26-F CONTROL VALVE, Pc.No

Transcription

1 26-F CONTROL VALVE, Pc.No JANUARY, 1987 NOTE: The following description and operation is based on this device and its components being new or this device and its components having been repaired, tested, installed and maintained in accordance with instructions issued by this and any other applicable Wabtec Corporation publications. WARNING: At the time any part is replaced in this device, the operation of the complete device must pass a series of tests prescribed in the latest issue of the applicable Wabtec Test Specification. At the time this device is applied to the brake equipment arrangement, a stationary vehicle test must be made to insure that this device functions properly in the total brake equipment arrangement. (Consult your local Wabtec Representative for identity of the test specification, with latest revision date, that covers this device.) IMPORTANT: Only Wabtec supplied parts are to be used in the repair of this device in order to obtain satisfactory operation. Commercially available non- O.E.M. parts are unacceptable. NOTE: The part numbers and their associated descriptions are the property of Wabtec Corporation and may not be replicated in any manner or form without the prior sole written consent of an Officer of Wabtec Corporation WABCO Locomotive Products. A Wabtec Company. All rights reserved January, 1987 Page 1 of 24

2 1. DESCRIPTION F CONTROL VALVE The 26-F Control Valve is a pneumatic device designed for use in a locomotive equipment arrangement where the air pressure does not exceed 150 psig. It functions to respond to service rate and/or emergency rate changes in brake pipe pressure to develop a brake cylinder pressure from brake pipe reductions with reference to a control reservoir pressure. This 26-F Control Valve is comprised of a Pipe Bracket Portion, Pc.No ; on which a Quick Release Portion, Pc.No and a Service Portion, Pc.No are mounted. A brief description of the various components of this 26- F Control Valve follows: 1.2 PIPE BRACKET PORTION The major components of the 26-F Control Valve are mounted on the Pipe Bracket Portion in such a way that they can be removed for servicing or maintenance without disturbing the piping of the equipment arrangement. Pipe connections to the 26-F Control Valve are made to the Pipe Bracket Portion. Two wire mesh air strainers, Pc.No , are incorporated into the design of the Pipe Bracket Portion. These air strainers are located in ports 5 and 7 of the Pipe Bracket Portion. These air strainers are to be replaced at the scheduled maintenance period. Pipe connections are designated numerically, and are so identified in the diagrammatic view, Figure 2. The Pipe Bracket Portion is designed to be semi-permanently attached to the locomotive. 1.3 SERVICE PORTION (Figure 2) The Service Portion contains a service spool valve, which includes two diaphragms selected for proper reference of brake cylinder pressure development guided by reduction in brake pipe pressure. The application and release valve element controls the movement of the air from the auxiliary reservoir to the brake cylinder. When a reduction in brake pipe pressure occurs, the service spool valve assembly moves upward to open the application valve. The service valve spool element also serves to exhaust the brake cylinder pressure at the Control Valve whenever the brake pipe pressure is increased. The diaphragm area ratios, together with the spring arrangement included in the Service Portion, permit stable operation of the automatic brake together with proper development of brake cylinder pressure. The Service Portion also includes a charging valve that functions to cut off the flow of air from the quick service volume of the Pipe Bracket Portion to atmosphere One charging check valve and two dissipating check valves are utilized in the design of this Service Portion. These check valves function to: Direct air flow to the auxiliary reservoir from the brake valve Direct air flow from the control reservoir into the brake pipe during direct release action of the Control Valve Direct brake pipe air from the spring chamber of the selector valve to the quick service volume of the Pipe Bracket Portion during the initial stages of a brake application A graduated release cap, which is used to manually position the 26-F Control Valve for Graduated or Direct Release is mounted on the Service Valve Portion. The letters REL. are cast on the body below the graduated release cap. The letters DIR. and GRA. are cast on the cap. When the letters DIR. are over the letters REL., the valve is set for Direct Release; when the letters GRA. are over the letters REL., the valve is set for Graduated Release. The cap is set by removing two cap screws and turning the cap so that either DIR. or GRA. line up with REL. on the body. The cap screws are then re-installed to secure the cap in position. IMPORTANT: Graduated Release (GRA. REL.) Position is to be used for passenger type locomotive service. Direct Release (DIR. REL.) Position is to be used for freight type locomotive service The selector valve, which is designed into the Service Portion, provides the quick service feature and controls the direct and graduated release functions The Service Portion also contains two brake cylinder limiting valves. These limiting valves are designated as the Service Limiting Valve and the Emergency Limiting Valve. They are designed to function to limit the maximum brake cylinder pressure during service and emergency brake applications. The maximum pressure output of the Emergency Limiting Page 2 of 24 January, 1987

3 Valve is predetermined by the load setting of the spring within this valve. The Service Limiting Valve is a check valve type limiting valve and has a manual adjustment feature for setting pressure output The Quick Release Portion of the 26-F Control Valve is designed to permit a release of an automatic brake application. When the Independent Brake Valve handle at the controlling cab station is depressed, air pressure developed at the Controlling Brake Valve should flow into the 26-F Control Valve to operate the small diaphragm and stem assembly in the Quick Release Portion. Movement of this small diaphragm and stem assembly interrupts and vents the air pressure developed in the line connected to the brake cylinder to atmosphere. Operation of the small diaphragm and stem assembly also initiates the operation of the larger diaphragm and stem assembly of the Quick Release Portion. This action vents a sufficient amount of control reservoir air to atmosphere in order to equalize the control reservoir pressure with brake pipe pressure. With the control reservoir and brake pipe pressures equal, the 26-F Control Valve functions to restrict a reapplication of the automatic brake, even if the Independent Brake Valve handle is released The control reservoir pressure retaining check valve in the Quick Release Portion protects against low control reservoir pressure whenever an independent quick release function is initiated following an emergency brake application. This check valve retains an amount of pressure in the control reservoir as determined at the check valve by the check valve spring. If the brake pipe has been reduced to zero psi during an emergency brake application, and if conditions at the time warrant dropping control reservoir pressure through the independent quick release function, then, when control reservoir pressure reaches the setting of the pressure retaining check valve, the check valve closes and retains sufficient pressure to provide available air for transmittal to the locomotive brake cylinders to effect a brake application on the locomotive if it is required. 2.0 OPERATION NOTE: Reference to Figure 2 will help make the operation of the 26-F Control Valve more easily understood. This diagrammatic view has been prepared for functional study and is to be used without regard to the actual proportion and/or construction of parts. 2.1 With the automatic brake valve handle at the controlling cab station in Release Position, brake pipe air directed into Port No. 1 of the 26-F Control Valve Pipe Bracket Portion flows to the following passages and chambers of the Control Valve: To the quick release valve and then to the chamber above the large diaphragm To the spring chamber of the selector valve To the brake pipe diaphragm chamber in the service valve To the brake cylinder emergency limiting valve, where the brake pipe pressure overcomes the force of the spring and moves the spool valve to its downward position To the control reservoir dissipation check valve To the auxiliary reservoir charging check valve Control reservoir air flows through choke plug H to the spool valve chamber of the selector valve and then is directed through choke plug G to charge the selector reservoir. 2.2 If the brake equipment is fully charged, identical pressures will exist above and below the large diaphragm in the service valve, and, with the aid of the large spring, the diaphragm assembly will be positioned in its downward position. 2.3 When a brake application is made, the brake pipe pressure in Port No. 1 should be reduced. This pressure reduction in brake pipe will occur in the spring chamber of the selector valve and the chamber above the large diaphragm of the service valve. The pressure differential that exists across the diaphragms will initiate movement of these valves. The selector valve assembly and stem movement will cause the following to occur Control reservoir air, charging the selector reservoir through choke plugs H and G, is cut off at the selector spool valve Quick service action occurs when brake pipe air in the spring chamber of the selector valve flows to the backflow check valve and then to the quick service volume. The air pressure in the quick service volume in the pipe bracket is dissipated through choke plug C and the passage which leads to the charging valve where the exhaust port is located Selector valve volume air is directed to exhaust at January, 1987 Page 3 of 24

4 Figure 2 - Diagrammatic View This diagrammatic representation is for functional analysis only. It is not to be used as an actual physical representation of portion or pipe bracket configurations. Page 4 of 24 January, 1987

5 the selector volume overcharge check valve by the selector valve spool. The selector valve volume air pressure is reduced to that of brake pipe air and then the exhaust is terminated by the selector spool valve. The selector valve is poised to respond to further decreases of brake pipe or to an increase of brake pipe pressure. 2.4 When the application valve is opened by the upward movement of the service valve stem, auxiliary reservoir air directed to port No. 5 in the pipe bracket is admitted into the device. This air flows through the brake cylinder service limiting valve and to the following chambers: To the face of the charging valve diaphragm, thus initiating a movement of the charging valve which cuts off the exhaust of brake pipe air from the quick service volume to atmosphere and cuts off brake pipe port 1b from control reservoir port 7a Through the Quick Release Portion to port No. 16 in the pipe bracket and then by piping to the brake cylinder relay valve located in the equipment arrangement To the large spring chamber in the service valve where a continued buildup of pressure forces the diaphragm assembly downward until the combined forces of the spring, the air pressure in the spring chamber, and the brake pipe pressure balance the force of the control reservoir air pressure. Whenever this balance point is reached, the service valve will assume a Lap Position To the underside of the brake cylinder service limiting valve. Whenever this air pressure increases to a point in excess of the force of the spring, the check valve seat moves upward to seat the check valve and cuts off any further flow of auxiliary reservoir air through the Control Valve. The value of the spring force, in effect, limits the maximum pressure delivered to the relay valve during a service application. 2.5 Whenever high brake pipe pressures are employed, it is possible to get over reductions with the 26-F Control Valve; however, an over reduction will not normally have any effect upon the brake cylinder pressure, since the brake cylinder relay valve pressure is determined by the load of the springs in the service and emergency limiting valves. 2.6 When the handle of the controlling automatic brake valve is placed in the Emergency Position, the 26-F Control Valve functions as previously described; however, several additional features designed into the Control Valve are utilized as follows: The increased pressure differential across the diaphragm in the selector valve, as a result of the greater drop of brake pipe pressure, positions the diaphragm to enable this valve to momentarily provide those features obtained during a service application The auxiliary reservoir air flows from the application check valve to the brake cylinder service limiting valve, and the brake cylinder emergency limiting valve. The brake pipe pressure in the emergency limiting valve drops sufficiently to permit the spring to move the spool valve upward, to unseat the check valve. The unseating of the check valve permits the auxiliary reservoir air to flow at a rate determined by the application choke D to the externally mounted brake cylinder relay valve as well as the other associated member chambers in the Control Valve. Whenever the brake cylinder relay valve pressure reaches a point high enough to overcome the force of the emergency limiting valve spring, the spool valve will be forced downward to close the check valve which cuts off any further flow of any air to the brake cylinder relay valve. 2.7 When the handle of the controlling automatic brake valve is placed in the Release Position, brake pipe pressure is increased. When this higher pressure is admitted into the brake pipe chamber above the large diaphragm in the service valve, all of the combined downward forces position the diaphragm assembly and stem to permit the brake cylinder relay valve pilot air to vent to atmosphere through the service valve stem and then to port No. 10 in the pipe bracket. It must be remembered that the air on the face of the charging valve diaphragm is also vented to atmosphere which permits the spring to move the charging valve to its normal position. The continued build-up of brake pipe pressure in the brake cylinder emergency limiting valve overcomes the force of the spring and holds the spool valve down, permitting the check valve to remain seated. 2.8 During a release of the locomotive brake, with the graduated release cap in direct release position, brake pipe builds up behind the diaphragm of the selector valve piston moving it to release position. This permits control reservoir air to flow through the spool valve of the selector valve, through the release cap and into the brake pipe. As a result of this action, equalization occurs between control reservoir and brake pipe pressures providing a full steady release of the brakes at the Service Portion. 2.9 If the graduated release cap is positioned in the graduated release position, then the brake pipe build-up will cause the selector valve to move to release position as before. However, control reservoir air directed through January, 1987 Page 5 of 24

6 the selector spool valve is cut off from brake pipe by the release cap, preventing equalization with brake pipe. Control reservoir air is also directed through the selector spool valve cavity where it flows into passage 9a through choke G and into passage 9 which is connected to the volume selector valve volume in front of the selector valve diaphragm. This causes the build-up of selector volume pressure until it exceeds brake pipe pressure behind the selector valve diaphragm and the valve moves to lap position which terminates the reduction of control reservoir pressure. Further movement of the brake valve handle towards release position starts this cycle again, providing the graduated release feature The selector volume overcharge check valve provides a protective feature when brake pipe operating pressure is changed or when brake pipe is reduced to a very low pressure. If such a situation occurs, that results in a change in brake pipe pressure or if brake pipe is reduced to a very low pressure, the selector volume is permitted to flow to exhaust through the selector volume overcharge check valve to a predetermined selector volume pressure. In this equipment arrangement the selector valve will move to release position when the brake pipe pressure is restored to a similar pressure. This reduces the likelihood of a premature release of the brake or an overcharged selector valve volume. 3.0 MAINTENANCE SCHEDULE IMPORTANT: At least ONCE EVERY TWENTY-FOUR MONTHS, or more frequently if service conditions so indicate, the Component Portions of the 26-F Control Valve are to be removed from the equipment arrangement, taken to the shop, completely disassembled, the parts cleaned, inspected, lubricated, the Portion(s) assembled, using specified NEW parts and tested for correct operation. 4.0 PARTS CATALOG & REPLACEMENT PART INFORMATION 4.1 PARTS CATALOG When ordering replacement parts for the 26-F Control Valve, or any of its component Portions, refer to the current issue of the Wabtec Corporation Parts Catalog , S.45. NOTE: The reference numbers used in this publication and those used in the Parts Catalog may differ. Check the descriptive parts name to be sure that the desired part is ordered. 4.2 REPLACEMENT PARTS IMPORTANT: To obtain satisfactory operation and reliability of this device, and its Component Portions, USE ONLY Wabtec Corporation replacement parts in the maintenance of this device and its Component Portions. 5.0 SAFETY PROCEDURES 7 WARNINGS Regular shop safety procedures MUST BE followed when working on the valve or any of the portions. The work area should be clean and free of debris. WARNING The following statements of warning apply all or in part wherever the symbol appears in the maintenance procedures. Failure to observe these precautions may result in serious injury to those performing the work and/or bystanders. The use of an air jet, which must be less than 30 p.s.i.g., to blow parts clean or to blow them dry after being cleaned with a solvent will cause particles of dirt and/or droplets of the cleaning solvent to be airborne. Wire brushing may also cause particles of dirt, rust, and scale to become airborne. These conditions may cause skin and/or eye irritation. When using an air jet, do not direct it toward another person. Improper use of air jet could result in bodily injury. Personal eye protection must be worn when performing any work on this device or its components parts to avoid any possible injury to the eyes. The use of solvents as cleaning agents and the use of lubricants can involve health and/or safety hazards. The manufacturers of the solvents and lubricants should be contacted for safety data (such as OSHA Form OSHA-20 or its equivalent). The recommended precautions and procedures of the manufacturers should be followed. When performing any test or work on devices or equipment while they are on the vehicle (on car test, etc.) special precautions must be taken to insure that vehicle movement will not occur which could result in injury to personnel and/or damage to equipment. Assembly may be under a spring load. Exercise cau- Page 6 of 24 January, 1987

7 tion during disassembly so that no parts Fly Out and cause bodily injury. All air supply and/or electric current to this device and/or to any components part must be cut-off before this device and/or any component part is removed from the equipment arrangement. Bottled up air under pressure (even though air supply is cut-off) may cause gaskets and/or particles of dirt to become airborne and an increase in sound level when this device and/or any component part is removed from the equipment arrangement. 7.0 SPECIAL TOOLS In addition to the regular shop tools, the following tools MUST BE available to the repair person. 7.1 #1 TRUARC Pliers 7.2 #3 TRUARC Pliers 7.3 Tool for removing the emergency limtitng valve bushing from the service portion. Dimensions for making this tool are shown on Drawing R-42-4, Figure 3. Personal eye and ear protection must be worn and care taken to avoid possible injury when performing any work on this device and/or component part. An adequate support or lifting device must be available to support the Device and/or Valve Portion(s) during removal, installation and maintenance procedures. 6.0 CLEANING SOLVENT, LUBRICANTS & SEALANT 6.1 CLEANING SOLVENT The solvent used for cleaning reusable parts of the 26-F Control Valve MUST BE an aliphatic organic solution, such as mineral spirits or naphtha, that will dissolve oil or grease and that will permit all parts to be cleaned without abrasion. 6.2 LUBRICANTS The following lubricants MUST BE available #2 Silicone Grease, Wabtec Corporation Specification M , which is used to lubricate o-rings, o-ring grooves or shoulders, and the bearing surfaces of bushings into which o-ring assemblies are installed A compound consisting of one part of graphite, Wabtec Corporation Specification M and two parts of SAE 20 oil, by weight. This compound is used to lubricate the threads of choke plugs prior to their installation and after they have been cleaned and inspected LOCTITE, Pipe Sealant with Teflon, Wabtec Corporation Specification M , used to coat the threads of the vent protector assembly when it is being installed. Figure 3 - Service Portion Emergency Limiting Valve Bushing Removal Tool (Drawing R-42-4) 7.4 Tool for assembling the charging valve diaphragm and piston into the service portion body. Dimensions for making this tool are shown on Drawing R-42-3, Figure Tool for disassembling and assembling the selector valve. Dimensions for making this tool are shown on Drawing R-42-5, Figure Holding Fixture, used during disassembly of the Quick Release Valve Portion. Dimensions for making this fixture are shown on Drawing R-42, Figure 6. IMPORTANT: The information for making tools as shown in Figures 3, 4, 5, and 6 is furnished as a convenience. The Wabtec Corporation shall have no responsibility for tools which they do not manufacture, nor will they be responsible for results of the use of any tools, including claims by third parties. January, 1987 Page 7 of 24

8 8.0 MAINTENANCE PROCEDURES FOR THE 26-F CONTROL VALVE COMPONENTS ON-CAR 8.1 REQUIRED REPLACEMENT PARTS The repair person will require the following NEW parts, and NEW or repaired and tested Component Portions. Figure 4 - Hand Tool for Assembling Diaphragms (Dwg. R-42-3) A NEW Quick Release Valve Portion, Pc.No , or a Quick Release Valve Portion, Pc.No , that has been overhauled and that has been tested following the procedures of the current issue of the Wabtec Corporation Test Specification T-2426-O A NEW quick release valve portion mounting gasket, Pc.No A NEW Service Portion, Pc.No , or a Service Portion, Pc.No , that has been overhauled and that has been tested following the procedures of the current issue of the Wabtec Corporation Test Specification T O A NEW service portion mounting gasket, Pc.No Figure 5 - Selector Valve Piston Assembly Tool (Dwg. R-42-5) The following NEW or cleaned and inspected choke plugs are required. Each choke plug should be in an individual container (plastic bab) which is clearly marked with the piece number and size of the choke plug. The threads of the choke plugs are to be lubricated with the oil and graphite compound as described in Section A 3 /8-18 x 3 /64" drill, Brass Choke Plug, Pc.No This choke plug is used in Port 1A of the service portion mounting face of the Pipe Bracket Portion A 3 /8-18 x #37 drill, Brass Choke Plug, Pc.No This choke plug is used in Port 5A of the service portion mounting face of the Pipe Bracket Portion A 3 /8-18 x #71 drill, Brass Choke Plug, Pc.No This choke plug is used in Port 6 of the service portion mounting face of the Pipe Bracket Portion A 3 /8-18 x 7/64" drill, Brass Choke Plug, Pc.No This choke plug is used in Port 10 of the service portion mounting face of the Pipe Bracket Portion. Figure 6 - Holding Fixture for Quick Release Piston (Drawing R-42) Two NEW wire mesh strainers (air filters) Pc.No One of the strainers is located in Port 5 of the Pipe Bracket Portion and the other is located in Port 7. Page 8 of 24 January, 1987

9 8.2 REMOVAL & REPLACEMENT OF COMPONENT PORTIONS - ON-CAR IMPORTANT: ALL operating property safety procedures and the safety procedures and WARNINGS listed in Section 5.0 MUST BE adhered to Clean all free dirt from the exterior surfaces of the 26-F Control Valve by wiping with a clean, lint-free cloth or by blowing clean with a low pressure jet of clean, dry air. (Figures 7 & 8) It will be necessary to break the pipe connections at Ports 5 and 7 of the Pipe Bracket Portion to gain access to the wire mesh air strainers (34). Pipe connections should be broken following operating property and/or locomotive builder instructions. Remove the strainers (34) from Ports 5 and Visually inspect the flange face of the Pipe Bracket to be sure that it is clean and that the Ports 5 and 7 are unrestricted. Install a NEW strainer (34) into Ports 5 and 7 and reconnect piping per operating property and/or car builder instructions QUICK RELEASE PORTION IMPORTANT: Provide an adequate support or lifting device to assist in the handling of the Quick Release Portion. This Portion weighs approximately 15 pounds. (Figures 7 & 8) Remove the four 3/8-16 hex nuts (1) which secure the Quick Release Portion to the Pipe Bracket Portion Remove the Quick Release Portion from the Pipe Bracket Portion. (Figure 8) Remove and SCRAP the quick release portion mounting gasket (36) Visually inspect the quick release portion mounting face of the pipe bracket portion to be sure that it is clean and that all ports are unrestricted. Ports may be blown out, if necessary, with a low pressure jet of clean dry air. Exercise care so that no dirt is blown into the Figure 7 - Exterior Views January, 1987 Page 9 of 24

10 ports or passages of the pipe bracket portion. The mounting surface MUST BE clean and free of defects. Use a dry, clean lint-free cloth to wipe the surface clean Remove ALL protective materials from a NEW or overhauled and tested Quick Release Portion, Pc.No Be sure that all masking and/or protective tape is removed from the check valve seal area, the wasp excluders and the pipe bracket face of the body Install a NEW quick release portion mounting gasket, Pc.No , (36) and the NEW or overhauled and tested Quick Release Portion, Pc.No on the Pipe Bracket Portion and secure them in place by installing four 3/8-16 hex nuts (1). Equally tighten the nuts Provide adequate protection to prevent dirt and/ or moisture from entering the removed Quick Release Portion and transport it ot the shop area for maintenance SERVICE PORTION IMPORTANT: Provide an adequate support or lifting device to assist in the handling of the Service Portion. This Portion weighs approximately 80 pounds. (Figures 7 & 8) Remove the four 1 /2-13 hex nuts (27) which secure the Service Portion to the Pipe Bracket Portion Remove the Service Portion from the Pipe Bracket Portion Remove and SCRAP the service portion mounting gasket (37) Visually inspect the service portion mounting face of the Pipe Bracket Portion to be sure that it is clean and free of defects and that the ports are not restricted. (Figure 8) The choke plugs (30, 31, 32, 33) located in the service portion mounting face of the Pipe Bracket Portion MUST NOW be replaced with NEW or cleaned and inspected plugs. IMPORTANT: Remove ONLY ONE choke plug at a time and replace it with a NEW or cleaned choke plug of the same size. Figure 8 - Pipe Bracket Portion - Exploded View Be sure that the threads of the replacement choke plugs are lightly coated with the oil and graphite compound listed in Section prior to their installation. Choke plugs are to be installed so that they are just below or even with the service portion mounting face of the Pipe Bracket Portion Remove choke plug (30) from Port 6 of the Pipe Bracket Portion and tag for identification. This should be a 3 /8-18 brass choke plug with a #71 drill, Pc.No Visually inspect the port from which choke plug (30) was removed to be sure that it is not restricted. If necessary, the port may be blown out with a low pressure jet of clean, dry air. Exercise care so that dirt is blown into the passages or ports of the Pipe Bracket. Remove ALL protective material from a NEW or cleaned and inspected 3 /8-18 brass choke plug with #71 drill, Pc.No , (30). Be sure that the threads are lightly coated with the oil and graphite compound as listed in Section Install the choke plug (30) into Port 6 of the Pipe Bracket Portion Repeat the procedures of Sections and for choke plugs 31, 32, and 33. The sizes and piece numbers of the plugs are as follows: Page 10 of 24 January, 1987

11 Reference 31. A 3 /8-18 brass choke plug with a 7/64" drill, Pc.No , for Port Reference 32. A 3 /8-18 brass choke plug with a #37 drill, Pc.No , for Port 5A Reference 33. A 3 /8-18 brass choke plug with a 3/64" drill, Pc.No , for Port 1A Remove ALL protective material from the NEW or overhauled and tested Service Portion, Pc.No Be sure that ALL masking and protective tape is removed from the vent protector seal areas, wasp excluders and the mounting face of the body Install a NEW service portion mounting gasket, Pc.No (37) and the Service Portion on the Pipe Bracket Portion and secure them in place by installing four 1 /2-13 hex nuts (27). Equally tighten the nuts Provide adequate protection for the removed Service Portion to prevent dirt or moisture from entering it while it is being transported to the shop area IMPORTANT: Whenever the 26-F Control Valve or any Portion or Component of the 26-F Control Valve is removed from the equipment arrangement for any reason and it is reinstalled or replaced with a NEW or repaired and tested Valve, Portion, or Component, a stationary vehicle test MUST BE made to be sure that the Portion, Component, and the 26-F Control Valve function properly in the brake equipment arrangement. Remove ALL wheel chocks before attempting to move vehicle. 9.0 CHOKE PLUGS - MAINTENANCE PROCEDURE - IN-SHOP 9.1 CLEANING & INSPECTING Choke plugs are to be cleaned individually - one at a time - in order to avoid mixing chokes of different sizes in the same bag or storage area Wash the choke plug in a bath of the cleaning solvent as described in Section 6.1. DO NOT use metal tools to clean the choke as the size and shape of the orifice MUST NOT BE changed Remove the choke plug from the solvent bath and Figure 9 - Pipe Bracket - Choke Plug Location and Identification blow it completely dry with a low pressure jet of clean, dry air Inspect the choke plug for damage. If it is damaged in any way, or if the size or shape of the orifice has been changed in any way, the plug is to be SCRAPPED. Refer to Parts Catalog , S.45 for correct drill size of the various choke plugs Use the graphite-oil compound as described in Section to coat the threads of the choke plug. Put the choke plug in a suitable plastic bag with tag indicating piece number and size of choke plug if it is going to be stored Continue the procedure for each of the choke plugs, until all are cleaned and inspected QUICK RELEASE PORTION - MAINTENANCE PROCEDURES - IN-SHOP (Figure 10) 10.1 DISASSEMBLY Lift the edge of the seal of the vent protector assembly (21), then using the #1 Truarc Retaining Ring Pliers, CAREFULLY remove the ring retainer (20), vent January, 1987 Page 11 of 24

12 Figure 10 - Quick Release Portion - Exploded View protector seal assembly (21), check valve spring (23) and check valve assembly (23, 24) from the body (25) Remove and SCRAP the rubber plug (24) from the check valve (23) Remove the four 3 /8-16 x 1" hex head cap screws (12) which secure the large diaphragm cover (13) to the body (25), then remove the cover (13) from the body (25) Remove and SCRAP the 15 /16" O.D. ring gasket (19) from the body (25) Remove the large diaphragm - piston assembly (14 to 18) as a unit from the body (25) Remove and SCRAP the two 1 /2" O.D. o-rings (17) from the stem of the piston (18) With the aid of the piston holding fixture (Figure 6), CAREFULLY remove the 1 /2-13 self-locking hex nut (14) from the piston (18), then remove the diaphragm follower (15) and diaphragm (16). SCRAP the diaphragm and the self-locking nut Remove the three 3 /8-16 x 1 1 /2" hex head cap screws (2) which secure the small diaphragm cover (4) and clamping ring (5) to the body (25) Remove the following parts from the body (25) Small diaphragm cover (4) Clamping ring (5) Spring (6) Small diaphragm - piston assembly (7 to 11) as a Unit Remove and SCRAP the five 5 /8" O.D. o-rings (10) from the stem of the piston (11) With the aid of the piston holding fixture (see Figure 6), CAREFULLY remove the 1 /2-13 self-locking hex nut (7), diaphragm follower (8), and diaphragm (9) from the piston (11). SCRAP the diaphragm and self-locking nut. Page 12 of 24 January, 1987

13 10.2 CLEANING & INSPECTING NON-REUSABLE PARTS ALL gaskets, o-rings, diaphragms and self-locking nuts ARE TO BE SCRAPPED and replaced with NEW Wabtec Corporation parts RE-USABLE PARTS (Figure 10) VENT PROTECTOR SEAL ASSEMBLY Using a clean, lint-free cloth that has been saturated with the cleaning solvent described in Section 6.1, wipe the vent protector seal assembly (21) clean. After cleaning, the assembly MUST BE dried completely. A low pressure jet of clean, dry air may be used to blow it dry Visually inspect the vent protector seal assembly for damage. If any of the parts, other than the seal are damaged, cut, broken, or bent, the assembly is to be SCRAPPED and replaced with a NEW Wabtec Corporation part. If ONLY the seal is damaged, cut, torn, or excessively worn, it may be replaced by cutting away the damaged seal and then working a NEW seal, Pc.No , onto the rivet (post) of the assembly REMAINING PARTS Wash ALL of the remaining parts in the cleaning solvent as described in Section 6.1. A clean, dry, lintfree cloth that has been saturated with the cleaning solvent may be used to assist in the cleaning of the interior and exterior surfaces of the body (25) and diaphragm covers (3 & 13). The springs may be wire brushed to assist in the removal of any dirt, rust, or scale After the parts are cleaned, they MUST BE dried completely. Use a low pressure jet of clean, dry air to blow the parts dry Inspect the springs. Replace ANY spring that is rusted, pitted, distorted, or that has taken a permanent set. Refer to the current issue of the Wabtec Corporation Parts Catalog , S.45 for spring information and identification Inspect the body (25) and small diaphragm cover (3). Replace either if found to be cut, broken, damaged internal bushings, excessively worn or if they are in such a condition that may result in the unsatisfactory operation of the Quick Release Portion. Be sure that the wasp excluder (4) of the small diaphragm cover (3) and the wasp excluder (26) of the body (25) are clean, unrestricted and free of damage. If necessary, replace the wasp excluder(s). The wasp excluder (4) in the small diaphragm cover (3) is a press type part and can be removed from the cover by inserting the blade of a small screw driver between the openings in the face of the excluder and prying it out of the body. Press a NEW part in place. The wasp excluder (26) in the body (25) is threaded and may be removed by carefully turning it out of the body. Screw a NEW part in place Inspect ALL of the remaining parts. Replace ANY part that is cracked, cut, broken, excessively worn, damaged in any way, or that is in such a condition that may result in the unsatisfactory operation of the Quick Release Portion ASSEMBLY (Figure 10) Install a NEW small diaphragm (9) on the small diaphragm follower (8) being sure that the bead of the diaphragm is in the bead groove of the follower, then place the small diaphragm and follower assembly (9, 8) onto the small piston (11) Place the piston (11) on the holding fixture (Figure 5) and then install a NEW 1 /2-13 self-locking hex nut (7) to secure the small diaphragm follower and diaphragm (8, 9) in place. Tighten the nut (7) securely BUT DO NOT overtighten and crimp the diaphragm. Be sure that the diaphragm (9) is properly positioned on the piston (11) and that the bead is in the bead groove of the follower (8). Remove the assembly from the holding fixture Coat the surfaces of five NEW 5 /8" O.D. o-rings (10) with #2 Silicone Grease, Wabtec Corporation Specification M Also fill the o-ring grooves on the stem of the piston (11) and lightly coat the bearing surfaces of the small piston bushing of the body (25) with the lubricant. January, 1987 Page 13 of 24

14 Install a NEW lubricated 5 /8" O.D. o-ring (10) into each of the five o-ring grooves on the stem of the piston (11). Any excess lubricant may be removed by wiping with a clean, dry, lint-free cloth Install the small diaphragm - piston assembly (7 to 10) as a unit into the proper bushing of the body (25) just far enough to permit the bead of the small diaphragm (9) to be pressed into the bead groove of the body (25). The diaphragm (8) is to be pressed into the bead groove using finger pressure Place the clamping ring (5) in position on the body (25) Install the small diaphragm spring (6) in the body (25) so it seats in the cavity of the diaphragm follower (8) Place a small diaphragm cover (4) in position on the clamping ring (5) Using three 3 /8-16 x 1 1 /2" hex head cap screws (2), secure the small diaphragm cover (4) and the clamping ring (5) to the body (25). Equally tighten the screws Install a NEW large diaphragm (16) onto the large piston (18) so that the inner bead of the diaphragm fits into the groove provided in the piston (18) and the outer bead of the diaphragm faces the tail end of the piston (18). Carefully install the diaphragm follower (15) onto the diaphragm and piston assembly (16, 18). Be sure that the bead of the diaphragm (16) remains in the bead groove of the piston (18) Place the large diaphragm, piston and follower assembly (15, 16, 18) on the holding fixture (Figure 5), then install a NEW 1 /2-13 self-locking hex nut (14) to secure the parts together. Tighten the nut securely BUT DO NOT overtighten and crimp the diaphragm. Be sure that the diaphragm (16) is properly positioned on the piston (18). Remove the assembly from the holding fixture Coat the surfaces of two NEW 1 /2" O.D. o-rings (17) with #2 Silicone Grease, Wabtec Corporation Specification M Also fill the o-ring grooves on the stem of the large piston (18) and lightly lubricate the bearing surfaces on the large piston bushing of the body (25) with the lubricant Install a NEW lubricated 1 /2" O.D. o-ring (17) into each of the two o-ring grooves on the stem of the large piston (18). Any excess lubricant may be removed by wiping with a dry, clean, lint-free cloth Install the large diaphragm piston assembly (14 to 17) into its bushing in the body (25) so that the outer bead of the diaphragm (16) comes to rest in the bead groove provided in the body (25). Using finger pressure, press the bead of the diaphragm (16) into its groove on the body (25) Install a NEW 15 /16" O.D. ring gasket (19) into its groove in the large diaphragm cover mounting face of the body (25) Place the large diaphragm cover (13) in position on the body (25). Make certain that the ring gasket (19) and the diaphragm (16) remains in their grooves Secure the cover (13) in place using four 3 /8-16 x 1" hex head cap screws (12). Equally tighten the screws Install a NEW rubber plug (24) in place in the check valve (23) Install the check valve with plug assembly (23, 24) into its cavity in the body (25), rubber plug end first Install the check valve spring (22) into the cavity of the check valve (23) Gently gather the seal of the vent protector seal assembly (21) around the rivet, then install the retaining ring (20) between the seal and wing washer of the seal assembly (21), then with the aid of the #1 Retaining Ring Pliers, install the seal and retaining ring assembly (21, 20) into the body (25) so that the washer of the assembly contacts the spring (22) and the retaining ring (20) snaps into its groove in the body (25) TESTING & ADDITIONAL INFORMATION IMPORTANT: After the Quick Release Portion, Pc.No , has been assembled, but before it is returned to service, it MUST pass a series of tests following the current issue of the Wabtec Corporation Test Specification T-2426-O IMPORTANT: Whenever an overhauled and tested Quick Release Portion, Pc.No , is installed in an equipment arrangement, a NEW mounting gasket MUST BE used and a stationary vehicle test MUST BE made to be sure that the Quick Release Portion functions properly in the equipment arrangement. Page 14 of 24 January, 1987

15 Consult your Wabtec Corporation Representative if additional information is required SERVICE PORTION - MAINTENANCE PROCEDURES - IN-SHOP 11.1 DISASSEMBLY (Figure 12) Remove the vent protector assembly (96) from the service valve portion body (101) Remove the cap nut assembly (48) from the bottom cover (49). Remove the two limiting valve piston springs (69, 68) and shims (67) (if used) Remove the five 1 /2-13 x 1 3 /4" hex head cap screws (47) which secure the bottom cover (49) to the body (101). Remove the bottom cover (49) Remove and SCRAP the 15 /16" O.D. ring gasket (81) from the cover mounting face of the body (101) Remove the large piston assembly (51 to 53) as a unit from the body (101) Remove the eight 1 /4-20 x 1 /2" self-locking hex socket head cap screws (50) which secure the diaphragm follower (51) and diaphragm (52) to the large piston (53) Remove the diaphragm follower (51) and diaphragm (52) from the large piston (53). SCRAP the diaphragm and the self-locking screws Remove the eight 1 /4-20 x 1 /2" self-locking hex socket head cap screws (54) which secure the small diaphragm cover (57) to the body (101) To assist in removing the small diaphragm cover (57) insert one of the 1 /4-20 hex socket head cap screws (54) into each of the tapped holes provided in the cover (57). The remainder of the screws are to be SCRAPPED. Remove the cover (57) from the body (101) Remove the pusher pin (55) from the small diaphragm cover (57) Remove and SCRAP the 9 /16" O.D. o-ring (56) from the small diaphragm cover (57) Remove the small piston assembly (58 to 62) from the body (101) Remove and SCRAP the two 3 /4" O.D. o-rings (59) from the stem of the small piston (60) Remove the six 1 /4-20 x 1 /2" self-locking hex socket head cap screws (58) which secure the diaphragm follower (62) and diaphragm (61) to the small piston (60). SCRAP the screws (58) Remove the diaphragm follower (62) and diaphragm (61) from the small piston (60). SCRAP the diaphragm (61) Remove and SCRAP the 9 /16" O.D. ring gasket (80) from the body (101) CAREFULLY remove the retaining ring (63) which secures the spring retainer (64) and small diaphragm spring (65) in the body (101) Remove the spring retainer (64) and small diaphragm spring (65) from the body (101) Remove the emergency limiting valve piston (71) with o-rings (66 & 70) as a unit from the limiting bushing (78) Remove and SCRAP the 1 1 /16" O.D. o-ring (66) and the 1 3 /4" O.D. o-ring (70) from the limiting valve piston (71) Use the emergency limiting valve bushing removal tool, as shown in Figure 3, to remove the limiting valve bushing (78) from the body (101) Remove and SCRAP the 1 1 /4" O.D. o-ring (76) and the 1-9/16" O.D. o-ring (77) from the limiting valve bushing (78) CAREFULLY remove the retainer (72) that holds the spring cage (73), check valve spring (74) and check valve (75) in the limiting valve bush (78) Remove the spring retainer (73), check valve spring (74) and check valve (75) from the bushing (78). SCRAP the check valve (75) Remove and SCRAP the 2 3 /8" O.D. o-ring (79) from the body (101). (Figure 11) Remove the four 3 /8-16 x 1 3 /4" hex head cap screws (34) which secure the selector valve cover (35) to the body (101). January, 1987 Page 15 of 24

16 Figure 11 - Service Portion Exploded View (1 of 2) Page 16 of 24 January, 1987

17 Figure 12 - Service Portion - Exploded View (2 of 2) January, 1987 Page 17 of 24

18 Remove and SCRAP the 15 /16" O.D. ring gasket (46) from the body (101) Remove the selector valve piston assembly (36 to 45) as a unit from the body (101) Remove and SCRAP the six 9 /16" O.D. o-rings (41) from the piston stem (43) Turn the spring retainer (44) on the piston stem (43) until the slot in the stem (43) and the slot in the piston stop (40) are in line Insert the selector valve piston tool, as shown in Figure 5, into the aligned slots of the piston stem (43) and piston stop (40). Remove the 1 /2-13 stop nut (36), diaphragm follower (37), diaphragm (38), piston (39), spring (45), spring retainer (44), and piston stop (40) from the piston stem (43). SCRAP the 1 /2" stop nut (36) and diaphragm (38) Remove and SCRAP the 5 /8" O.D. o-ring (42) from the piston stem (43). (Figure 12) Lift the edge of the vent protector seal assembly (98) and CAREFULLY remove the following parts from the body (101) Retaining ring (97) Vent protector seal assembly (98) Check valve spring (99) Check valve assembly (100, 100A). Remove and SCRAP the rubber plug (100A) from the check valve (100). (Figure 11) Remove the four 3 /8-16 x 1" cap screws (20) which secure the service valve cover (21) to the body (101). Remove the service valve cover (21) Remove and SCRAP the cover gasket (22) Remove the check valve spring (23) Remove and SCRAP the three rubber check valves (30, 31, 32) Remove the check valve guide - spring guide - check valve assembly (24 to 29) as a unit from the body (101) Remove and SCRAP the 1 1 /4" O.D. o-ring (28) from the check valve guide (29) CAREFULLY remove the check valve retaining ring (26) from the guide (29). Remove and SCRAP the check valve (27) Remove the spring guide assembly (24,25) from the check valve guide (29) Remove and SCRAP the 13 /16" O.D. o-ring (24) from the spring guide (25) Remove the sealing wire (1) and the two 3 /8-16 x 1" hex head cap screws (2) which secure the limiting valve cover - adjusting screw assembly (3 to 9 incl.) to the body (101). SCRAP the sealing wire (1). Remove the cover adjusting screw assembly (3 to 9 incl.) as a unit from the body (101). Disassemble the unit as follows: Using the proper tool, CAREFULLY remove the 3 /32" x 1 /2" cylindrical spring pin (3) from the adjusting screw (9) Remove the hex adjusting collar (4) and 1/4" spacer (5) from the adjusting screw (9) Remove the adjusting screw - spring seat assembly (8, 9) as a unit from the limiting valve cover (6). Remove the spring seat (8) from the adjusting screw (9) Remove and SCRAP the 3 /8" O.D. o-ring (7) from the cover (6) Remove the spring (10) Remove and SCRAP the 1 7 /8" O.D. ring gasket (19) from the body (101) Remove the valve guide and seat sub-assembly with o-rings (11 to 18) as a unit from the body (101) Remove and SCRAP the two 1 1 /4" O.D. o-rings (18) from the valve seat (17) Using the proper tool, carefully remove the retaining ring (11), which secures the valve guide (12) in Page 18 of 24 January, 1987

19 place, from its groove on the inside of the valve seat (17) Remove the valve guide with o-ring assembly (12, 13), the spring (14) and the valve with o-ring assembly (15,16) from the valve seat (17). SCRAP the valve with o-ring (15,16) Remove and SCRAP the 15 /16" O.D. o-ring from the valve guide (12). (Figure 12) Remove the four 3 /8-16 x 1" hex head cap screws (85) which secure the charging valve cover (86) to the body (101). Remove the cover (86) from the body (101) Remove and SCRAP the charging valve piston diaphragm (87) from the piston (90) Remove the charging valve piston (88,90) and with o-ring assembly spring (89) from the body (101) Remove and SCRAP the four 1 /2" O.D. o-ring (88) from the stem of the piston (90) Remove and SCRAP the 7 /8" O.D. ring gasket (91) from the body (101) Remove the two 3 /8-16 x 1 1 /8" hex head cap screws (82) which secure the graduated and direct release cap (83) and gasket (84) to the body (101) Remove the release cap (83) and gasket (84) from the body (101). SCRAP the gasket (84) CLEANING & INSPECTING RE-USABLE PARTS BODY Wash the body (101) in the cleaning solvent described in Section 6.1. A clean, lint-free cloth that has been saturated with the cleaning solvent may be used to clean the interior and exterior surfaces of the body After cleaning, the body MUST BE dried completely. Use a low pressure jet of clean dry air to blow the body dry Inspect the body. If it is damaged in any way, or if it shows signs of excessive wear, it is to be replaced with a NEW body If the body passes inspection, the choke plugs (33, 92, 93 and 95) are to be serviced following the procedure of Section IMPORTANT: ONLY ONE choke plug is to be removed and serviced at a time. Choke plug (95) is located in passage G of the body behind a 3 /8" pipe plug (94). Choke plug (93) is located in passage J of the body behind a 3 /8" pipe plug (94). The pipe plugs (94) should be serviced in the same manner as choke plugs (93 & 95) The orifice size of the 3 /8 NPT brass choke plug (92), Pc.No , is a #60 drill The orifice size of the 1 /4 NPT brass choke plug (93), Pc.No , is a #65 drill The orifice size of the 1 /8 NPT brass choke plug (95), Pc.No , is a #59 drill The orifice of the 1 /8 NPT brass choke plug (33), Pc.No , is a #50 drill REMAINING RE-USABLE PARTS Wash all the remaining re-usable parts in the cleaning solvent described in Section 6.1. Springs may be wire brushed to assist in removing any dirt, rust or scale After the parts are cleaned, they MUST BE dried completely. Use a low pressure jet of clean, dry air to blow parts dry Inspect the parts Replace any spring that is rusted, pitted, or that has taken a permanent set. See Parts Catalog , Sup. 45 for spring identification and information Replace any retaining ring that is not elastic enough to hold securely Replace any wasp excluder that is broken or damaged in any way or that cannot be easily cleaned. A wasp excluder is located in the cap nut shown in Figure 12 as Ref. (48A) and in the limiting valve cover shown in Figure 11 as Ref. 6A. (Figure 12) Visually inspect the vent protector assembly (96). If the body of the assembly is damaged in any way, January, 1987 Page 19 of 24