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1 HWH Online Technical School Lesson 13: Hydraulic Leveling System Identification and Operation PART 2 Computer-Control (Automatic) Leveling Systems The 400 Series 610 Central Ground Series (400 / 500 / 510 / 600 / 610 / 610-CG) (Filename: ML DOC Revised: 15MAY16) CHAPTER 1 Introduction Click Here for Printable PDF File CHAPTER Series, Paddle Switch-Controlled NON-BI-AXIS 2-1 Electrical Component Functions 2-2 Hydraulic Component Functions 2-3 How the 400 Series NON-BI-AXIS System Works Manual Operation 2-4 How the 400 Series NON-BI-AXIS System Works Automatic Operation CHAPTER Series, Paddle Switch-Controlled BI-AXIS 3-1 Electrical Component Functions 3-2 Hydraulic Component Functions 3-3 How the 400 Series BI-AXIS System Works Manual or Automatic Operation CHAPTER Series, Touch Panel/Computer-Controlled BI-AXIS 4-1 Electrical Component Functions 4-2 Hydraulic Component Functions 4-3 How the 500 Series System Works Manual Operation 4-4 How the 500 Series System Works Automatic Operation CHAPTER Series, Touch Panel/Computer-Controlled BI-AXIS 5-1 Electrical Component Functions 5-2 Hydraulic Component Functions 5-3 How the 510 Series System Works Manual Operation 5-4 How the 510 Series System Works Automatic Operation CHAPTER Series, Touch Panel/Computer-Controlled BI-AXIS CHAPTER Series, Touch Panel/Computer-Controlled BI-AXIS 7-1 Electrical Component Functions 7-2 Hydraulic Component Functions 7-3 How the 610 Series System Works Manual Operation 7-4 How the 610 Series System Works Automatic Operation CHAPTER CG Series, Touch Panel/Computer-Controlled Central Ground (CG) BI-AXIS CONCLUSION TEST 8-1 Electrical Component Functions 8-2 Hydraulic Component Functions 8-3 How the 610 CG Series System Works Manual Operation 8-4 How the 610 CG Series System Works Automatic Operation C:\0_Web\ml57000(SchoolTech)\ml doc Page 1 of 56 Revised: 15MAY16

2 CHAPTER 1 - INTRODUCTION LESSON 13 PART 2, deals with identifying the different early HWH computerized, automatic hydraulic leveling systems and the basic operation of each system. To properly diagnose problems or obtain parts for repairs, you not only have to be able to identify which system you are working on, you also have to know how that system should function. For example, a 510 Series system with kick-down jacks functions differently than a 610 Series system with kick-down jacks. Although all automatic leveling systems up to and including the 625S Series Single-Step leveling system used jacks with single-acting cylinders, some present day automatic computerized leveling systems will use jacks with a double-acting cylinder. There are two basic types of leveling systems, the manual systems and the automatic computerized systems. The manual systems are covered in LESSON 13 PART 1. With automatic computerized systems, all functions of the leveling procedure, including air dump, are controlled by a computer that is part of the system. Store functions, like manual touch panel systems, are automatic. Automatic systems also have manual capability for operator control. Control panels, control boxes, valves, and other system features will be used in the identification of the systems. Due to the visual similarity of touch panels and control boxes, it is important to understand less obvious differences. Several touch panels are actually used with two different Series control boxes. The differences may be (but not limited to) the style of touch panel cable, valve arrangements on the hydraulic manifolds or even the type of warning switch used. Most of the computerized hydraulic leveling systems have a repair manual available but it is necessary to identify the system to obtain the correct manual. For example, there are two completely different 610 Series leveling systems. Each has its own repair manual. Much of the diagnostics for each system is not interchangeable. Using the wrong manual will probably result in an incorrect diagnosis of the issue. IMPORTANT: It would be very helpful to study LESSON 8 (Hydraulics and HWH ) and LESSON 9 (Electronics and HWH ) before continuing with this lesson or working on HWH equipment. These two lessons identify the individual system components along with their function and some diagnostics. This lesson will deal with some component information but not in great detail. As you study this lesson, refer back to LESSON 8 and LESSON 9 to get greater detailed information about specific components. If you want to review a specific system, return to the lesson directory and click on the system you wish to review. This lesson only covers systems for motorized vehicles. Note: For most systems (not all) there are complete schematics, diagrams and/or comprehensive repair manuals on the HWH web site at These will be located under Tech Support, Manuals, Online Schools. C:\0_Web\ml57000(SchoolTech)\ml doc Page 2 of 56 Revised: 15MAY16

3 CORPORATION CORPORATION CHAPTER SERIES, PADDLE SWITCH-CONTROL NON BI-AXIS SYSTEMS The 400 Series paddle switch system was the first computerized, automatic leveling system developed by HWH. The paddle switch systems are easily recognized by the control panel. The panel incorporates a Series of flat toggle type switches or paddle switches. STANDARD 400 SERIES PADDLE SWITCH PANEL MASTER ON EMERGENCY OFF R HWH CORPORATION LEVEL STORE 400 SERIES PADDLE SWITCH PANEL WITH REMOTE ON/OFF PANEL MASTER ON AUTOMATIC LEVELING MANUAL OPERATION HORIZONTAL MASTER ON AUTOMATIC LEVELING MANUAL OPERATION HORIZONTAL EMERGENCY OFF AUTOMATIC VERTICAL RETRACT CAUTION! BLOCK FRAME SECURELY BEFORE CHANGING TIRES OR WORKING UNDER VEHICLE. 5 AMP HW R H LEFT REAR LEFT FRONT RIGHT FRONT RIGHT REAR RETRACT RETRACT RETRACT HOLD HOLD HOLD EMERGENCY OFF CAUTION! AUTOMATIC RETRACT VERTICAL BLOCK FRAME SECURELY BEFORE CHANGING TIRES OR WORKING UNDER VEHICLE. LEFT REAR RETRACT LEFT FRONT RETRACT RIGHT FRONT RETRACT 5 AMP HW R H RIGHT REAR EXTEND EXTEND EXTEND HOLD HOLD HOLD TO PREVENT DAMAGE FROM OVERHEATING DO NOT HOLD SWITCH ON FOR MORE THAN TWO OUT OF EVERY FOUR MINUTES. EXTEND EXTEND EXTEND TO PREVENT DAMAGE FROM OVERHEATING DO NOT HOLD SWITCH ON FOR MORE THAN TWO OUT OF EVERY FOUR MINUTES. Figure 1 Not only does the panel have the control switches, it also contains the computer chip, control outputs and information inputs. There is no separate control panel and control box. The control outputs would be for the solenoid valves, the relays on the pump, a master warning light control and air dump control when so equipped. The information inputs would be the jack down warning switches, the level sensing unit and the hydraulic manifold pressure switch. There were quite a few different control panels. There were panels for straight-acting or kick-down style jacks. A different control panel was needed if air dump was used. There were different programs that may have extended one or two jacks when automatically leveling. There were even panels where the only difference was the color of the panel lexan; there were gray, black, brown, and silver lexans. The standard 400 Series panel was like the 100/110 Series lever controlled leveling systems. The panel was designed to control individual jacks. Even in the automatic mode, with a few exceptions, these systems operated individual jacks while leveling the vehicle. There is a BI-AXIS 400 Series leveling system. This system will be discussed in the next chapter of this lesson. The BI-AXIS panel has different text above the yellow paddle switch lens. Instead of LEFT REAR LEFT FRONT RIGHT FRONT RIGHT REAR that is on the standard panels (Figure 1), a BI-AXIS panel has LEFT SIDE FRONT RIGHT SIDE REAR above the yellow lens. (CHAPTER 2, Figure 6) The BI-AXIS hydraulic manifold is also totally different than the hydraulic manifold used with the standard 400 Series paddle switch systems. Many of the 400 Series panels have been obsoleted. ML11428QR 004 is a quick reference sheet that lists all the 400 Series panels that have been available along with a panel that can be used to replace the existing panel if it has been obsoleted. The replacement panel may have a different color lexan and have a slightly different leveling program. This sheet is available on the HWH web site. At this time, the 400 Series systems can still be serviced with new, remanufactured or repaired parts. It may be possible in the future that due to availability of certain components, HWH will not be able to supply the parts necessary to repair the system. The system may have to be replaced with a system available at that time. Depending on what systems are available, it may be possible some of the existing components such as the jacks, hoses, and pump can be used with a newer control system. 2-1 Electrical Component Functions The 400 Series systems (including the BI-AXIS systems) are unlike all of our other computerized systems. All other computerized systems have a touch panel and a control box or I/O module. The 400 switch system only has the paddle switch control panel. All inputs from the warning switches, manifold pressure switch, and the level sensing unit are routed to the paddle switch panel. All of these input signals are switched grounds from the component. Ignition power goes directly to the panel. Like other systems, it was recommended to use the ACC. side of the ignition switch. The ignition/acc. wire is in a two pin plug with the ground wire for the panel. The ignition and ground wire are twisted together to C:\0_Web\ml57000(SchoolTech)\ml doc Page 3 of 56 Revised: 15MAY16

4 reduce noise on the power wire. Control output signals for the solenoid valves, the relays, the master warning light and air dump (if so equipped), come directly from the paddle switch panel. Most paddle switch panels had either six or seven switches and a five amp glass fuse. There is an ON/OFF switch, an AUTOMATIC LEVEL/AUTOMATIC RETRACT switch, a HORIZONTAL/VERTICAL switch (if the system was equipped with kick-down style jacks), and four individual jack switches for manual control of the jacks. The indicator lights for the panel are part of the paddle switches. Each switch can have two lights. The switches have a removable lens on each side of the switch. The indicator light bulbs are located beneath the lens and are replaceable. There is a small metal tab under the lens that when pulled up, pops the bulb out for replacement. There were different colored lens used. A red lens was used on each side of the ON/OFF switch, AUTO LEVEL/RETRACT switch and the HORIZONTAL/ VERTICAL switch, when present. On some panels, the lower lens on the ON/OFF switch was a red lens with LOW VOLTS printed on it. The manual jack control switches had yellow lens on the top side of the switch for the level indicator lights and a red lens on the bottom of the switch was the jack down indicator light. Some Blue Bird panels had a black lens on the lower side of the jack control switches due to the fact Blue Bird supplied their own jack down indicator lights. AUTOMATIC "LEVELING" & "RETRACT" SWITCH SYSTEM ON LIGHT MASTER ON/EMERGENCY OFF SWITCH LOW VOLTS LIGHT (OPTIONAL) INDIVIDUAL JACK CONTROL SWITCHES (4) WARNING LIGHTS (4 Red) MASTER ON LOW VOLTS EMERGENCY OFF LEFT REAR RETRACT HOLD EXTEND AUTOMATIC LEVELING AUTOMATIC RETRACT LEFT FRONT RETRACT HOLD EXTEND MANUAL OPERATION HORIZONTAL VERTICAL CAUTION! BLOCK FRAME SECURELY BEFORE CHANGING TIRES OR WORKING UNDER VEHICLE. RIGHT FRONT RETRACT HOLD EXTEND FUSE 5 AMP. R HWH CORPORATION RIGHT REAR AUTOMATIC LEVELING LIGHT "HORIZONTAL/VERTICAL" SWITCH CONTROL FUSE (5 AMP) AUTOMATIC RETRACT LIGHT LEVELING LIGHTS (4 Yellow) TO PREVENT DAMAGE FROM OVERHEATING DO NOT HOLD SWITCH ON FOR MORE THAN TWO OUT OF EVERY FOUR MINUTES. Figure 2 Most of the paddle switches were three position ON/OFF/ON momentary switches. Some panels had a two position ON/OFF maintain switch. Panels that had the two position ON/OFF switch did not have an automatic off feature. The ON/OFF switch was pushed to the ON position to operate the system and had to be pushed to OFF, or EMERGENCY OFF on some panels, to turn the system off. Panels that have an automatic off feature used the three position (ON/OFF/ON) switch for the ON/OFF switch. Some systems were equipped with a remote panel that had the ON/OFF switch and the AUTOMATIC LEVEL / AUTOMATIC RETRACT switch. The main paddle switch panel for these systems did not have the ON/OFF switch or the AUTOMATIC LEVEL/AUTOMATIC RETRACT switch. Because of the design of the paddle switch control panel, the panel switches a ground to control the pump relay, the hydraulic manifold solenoid valves and the air dump valves if so equipped. In the automatic mode, because these ground signals come from a small driver chip controlled by the processor, the ground signal is very weak. A transistor is needed for each component controlled by the paddle switch panel. There is a transistor for the pump relay mounted on a breaker/fuse panel mounted to the hydraulic manifold. That same panel will have a transistor for the air dump valves if an air dump system is used. HYDRAULIC MANIFOLD ASSEMBLY RIGHT REAR RIGHT FRONT HORIZONTAL VERTICAL LEFT FRONT Figure 3 STABILIZE LEFT REAR C:\0_Web\ml57000(SchoolTech)\ml doc Page 4 of 56 Revised: 15MAY16

5 Each solenoid valve on the manifold has a transistor mounted to the exterior of the valve. All of these transistors supply a ground to their components when the control panel grounds the transistor. Proper grounding of the hydraulic manifold is critical to the operation of the system. If the manifold has a weak ground due to loose mounting bolts, corrosion, or other issues, the component transistors will burn out. A transistor can become totally inoperative, the component will not function at all, or can become shorted to ground and the component will be on whenever the master relay is on. A valve can be open or the pump can run whenever the panel is on. Even if the manifold has a good ground, corrosion or loose mounting bolts can cause an issue with the transistors on the breaker/fuse panel mounted to the manifold. Again, the manifold and the breaker/fuse panel with transistors mounted to the manifold require good, clean and tight mounting connections to ensure proper system operation. The breaker/fuse panel supplies power for the solenoid valves along with having the pump and air dump transistors. Originally, the panel was equipped with three automatic circuit breakers. An automatic circuit breaker will reset on its own after a cooling period. Some very early panels only had two breakers. Later, the breakers were replaced with three 20 amp inline automotive blade fuses. Each breaker or fuse supplies power to two solenoid valves. Newer panels are equipped with a panel ground wire to help insure a good ground for the panel. A huge difference between all manually controlled leveling systems and the computerized automatic leveling systems is the relay arrangement for the pumps. The manual systems all have one relay to control the pump. (Some manual systems used two pump relays if the vehicle was equipped with an HWH room extension.) All automatic leveling systems have two relays for the pump. There is a master relay and a pump relay. (Like with manual systems, there are different relay arrangements but all automatic leveling systems have at least one master and one pump relay.) The master relay is used to control power to operate the pump motor and the hydraulic manifold solenoid valves. The master relay is controlled with a +12 volt signal from the control panel when the control panel is on. The pump relay is controlled with a ground signal from the control panel through a transistor on the breaker/fuse panel. The +12 voltage for the pump relay coil is supplied from the switched side of the master relay. The master relay must be on for the pump to run. Both the master and pump relays used with the 400 systems were continuous duty relays with the same part number. The same relay used on the 400 systems is still available from HWH today. An intermittent duty relay, like those used on present day systems, can be used for the pump relay, but will create some minor mounting and wiring problems. Note: Detailed wiring diagrams for the 400 Series system are available in the repair manual for this system. The manual number is ML7879 and can be found on the HWH web site under Service Manuals in the Technical and Installation Information section of the web site. As with all leveling systems, the 400 Series jack down warning switches, the manifold pressure switch and the level sensing unit all provide a switched ground to the control panel. Due to the early technology used, the manifold pressure switch and the level sensing unit were connected to the control panel with a shielded cable to reduce electronic interference or noise that could inhibit operation of the system. There are small wires for the shielding cable that need to be grounded at the sensing unit and the manifold pressure switch. C:\0_Web\ml57000(SchoolTech)\ml doc Page 5 of 56 Revised: 15MAY16

6 Sensing units for the 400 Series systems used a five wire harness plus the shield wire that is grounded at the sensing unit. One of the five wires is a ground for the sensing unit. The other four wires were the signal wires. Each wire controls one yellow level light. The sensing unit is mounted in an X position to read the corners of the vehicle. The sensing unit also has an UP position. The sensing units have a sticker that indicates the proper mounting direction and the UP side of the sensing unit. There are three mounting screws with a spring between the sensing unit and mounting surface at each screw. The mounting screws are also the adjusting screws. The original sensing units have mercury bulbs as part of the assembly and are not available any more. A new style electronic sensing unit can be used to replace the original sensing unit but will need an adaptor harness kit so it will function properly. Contact HWH technical service for assistance. SHIELDING STRAP MOUNTING SURFACE SPRINGS (3) SCREWS (3) REAR Figure 4 THIS SIDE UP The jack down warning switches used with the 400 Series systems switch a ground to control the red jack down warning lights on the control panel. Warning switches used with straight-acting jacks were different than switches used today. The older straight-acting jacks used a side port switch or a two inch plunder switch mounted on the top of the jack. Straight-acting jacks would extend approximately two inches before turning on the warning lights. These older switches were one wire switches and were grounded through the jack itself. A rusted pivot point on these jacks could cause a warning light to not come on. The kick-down jack warning switches were basically the same as used today. The main difference was the switch was grounded at the jack mounting bracket so the warning switch harnesses only had one wire per jack. Refer to SECTION 2-8 in LESSON 9, Electronics and HWH for detailed views and explanations for the warning switches used with the 400 systems. The 400 Series system is the only automatic system where the jack down warning switches are not used for any part of system operation except the panel red warning lights. A warning switch that will not turn on or off will not interfere with any automatic leveling or store function. 2-2 Hydraulic Component Functions The only thing that is similar between present day leveling systems and the 400 Series non-bi-axis leveling system is the use of single-acting cylinders for the jacks. The manifold and pump are mounted separately and can be in different locations. The manifold and pump are connected with a pressure line to deliver fluid to the manifold and a low pressure line for fluid return to the pump. The manifold uses six solenoid valves if kick-down style jacks are used and five solenoid valves if straightacting jacks are used. The manifold also uses a shuttle valve, an individual check valve for each jack, an adjustable pressure reducing valve, a pressure switch and if kick-down jacks are used, a relief bleed valve for thermal expansion. Review CHAPTER 4 of LESSON 8, Hydraulics and HWH for detailed explanations of the different hydraulic components such as shuttle valves and actuators. Note: Detailed hydraulic plumbing diagrams for the 400 Series system are available in the repair manual for this system. The manual number is ML7879 and can be found on the HWH web site under Service Manuals in the Technical and Installation Information section of the web site. C:\0_Web\ml57000(SchoolTech)\ml doc Page 6 of 56 Revised: 15MAY16

7 All 400 Series manifolds have one solenoid valve for each jack. The manifolds also will have a stabilize valve. If the system has kickdown jacks, the manifold will be equipped with a horizontal/vertical valve. All of the solenoid valves on the manifold are the same and are interchangeable. The valves are normally closed, zero leak valves. The jack valves open to extend and retract the jack cylinders. The stabilize valve opens during automatic leveling to stabilize the vehicle after leveling is complete. The adjustable relief valve lowers the pump pressure during the stabilize procedure. The four individual jack check valves allow low pressure fluid to flow to jacks that need to extend during the stabilize procedure while keeping jacks already under a higher pressure in their present position. The horizontal/vertical valve opens to move jacks to the vertical or horizontal position. The bleed valve is not shown in Figure 5. The shuttle valve and the relief valve must be removed to access the bleed valve. HORIZONTAL/VERTICAL KICK-DOWN JACKS ONLY STABILIZE PRESSURE SWITCH LEFT REAR CHECK S (4) ACTUATOR CONNECTION KICK-DOWN JACKS ONLY PUMP + STAB + + LEFT FRONT STAB RIGHT FRONT ADJUSTABLE RELIEF RETURN LINE PRESSURE LINE Figure 5 + RIGHT REAR MAIN CYLINDER CONNECTIONS (4) SHUTTLE The bleed valve relieves pressure between the jack kick down actuators and the manifold caused by thermal expansion so jacks will not kick down to a vertical position while the vehicle is traveling. The shuttle valve blocks the return line to the pump when the pump is running. The pressure switch is used to indicate an excess slope situation. Most 400 Series systems use a 3000 psi pressure switch although some early systems used a 2500 psi pressure switch. Systems with kick-down style jacks have two hydraulic hoses routed from the manifold to each jack. One hose is for the kick down actuator cylinder and the other hose is for the main jack cylinder. The hose for the actuator is a common hose teed to each jack actuator. There is only one connection at the manifold for all four jack actuators. There is an individual connection at the manifold for each jack cylinder. 2-3 How the 400 Series System Works Manual Operation Manual leveling: The ignition key must be on and the park brake should be set. The 400 Series systems do not use a park brake signal to inhibit system operation. If the system uses kick-down jacks, the front of the vehicle should be the low end. Lifting the weight of the vehicle off of the rear wheels will allow the vehicle to roll off of kick-down jacks. Note: If the vehicle is equipped with an air suspension, air should be dumped before a leveling procedure is started. If the vehicle has kick-down jacks, the air should be dumped after the jacks are in the vertical position. Push the ON/OFF paddle switch to the on position. The red system on light should come on. The panel will send a +12 volt signal to turn the master relay on. The master relay supplies power to the breaker/ fuse panel for the solenoid valves and to the pump relay. C:\0_Web\ml57000(SchoolTech)\ml doc Page 7 of 56 Revised: 15MAY16

8 If the system has kick-down jacks, push and hold the Horizontal/Vertical paddle switch to the Vertical position. The panel will send a ground signal to the breaker/fuse panel pump transistor. The pump transistor sends a ground signal to the pump relay. The pump relay contacts will close and send +12 volts to the pump motor. The panel, at the same time, sends ground signal to the Horizontal/Vertical valve. With the pump running and the valve open, pressure forces the jack actuators to push the jacks to the vertical position. When all four red jack down warning lights are on, release the Horizontal/Vertical paddle switch. If the system has straight-acting jacks or when the jacks are in the vertical position, the jacks can be extended to level the vehicle by pushing individual jack control paddle switches to the Extend position. Pushing a switch to the Extend position sends a ground signal to the pump transistor on the breaker/fuse panel and the appropriate jack solenoid valve. The pump will push oil to that jack and the jack will extend until the switch is released. The system level sensing unit will send a ground signal to the panel to turn on a yellow level light. A lit level light indicates a corner of the vehicle is low. One or two level lights can be on at the same time. Opposing level lights such as the right front and the left rear should not be on. Push and hold the appropriate jack control paddle switches until the yellow lights are all out. Push and hold the paddle switch or switches for jacks not used to level the vehicle. These jacks should be extended until they lift the vehicle slightly, approximately ½ inch. Manual retract: The ignition must be in the ON or ACC. position to use the manual control paddle switches to retract the jacks. Push the ON/OFF paddle switch to the on position. The red system on light should come on. The panel will send a +12 volt signal to turn the master relay on. The master relay supplies power to the breaker/ fuse panel for the solenoid valves. Push and hold the manual jack control paddle switches to RETRACT. This sends a ground signal to open the solenoid valves and allows the fluid to return to the pump from the jacks. If the system has straight-acting jacks, hold the paddle switches to RETRACT until the red jack down warning lights are out. Remember, the red warning light goes out with the foot of the jack still extended one to two inches. Hold the paddle switches to RETRACT for five to ten seconds after the red warning lights go out. This will help make sure the foot of the jack is fully retracted. If the system has kick-down jacks, the foot of the jack must be off the ground before the jack can return to the vertical position. It will be necessary to visually check that the jacks are retracted far enough to swing the jacks to the vertical position. When all jacks will clear the ground, push and hold the HORIZONTAL/VERTICAL paddle switch to VERTICAL until all red jack down warning lights are out. Use the individual jack control switches to make sure the foot of each jack is fully retracted. Note: It may be best to retract the front jacks together and then the rear jacks together. This can help reduce twisting of the vehicle while retracting the jacks. 2-4 How the 400 Series System Works Automatic Operation Automatic leveling: The ignition key must be on and the park brake should be set. The 400 Series systems do not use a park brake signal to inhibit system operation. If the system uses kick-down jacks, the front of the vehicle should be the low end. Lifting the weight of the vehicle off of the rear wheels will allow the vehicle to roll off of kick-down jacks. Note: If the vehicle has an air suspension but is not equipped with an HWH air dump system. The suspension air should be dumped using an air dump system supplied by the coach manufacturer. If the vehicle has straight-acting jacks, dump the air before starting the leveling procedure. If the vehicle has kick-down jacks, dump the air after the jacks are put in the vertical position but before starting the leveling procedure. Push the ON/OFF paddle switch to the on position. The red system on light should come on. The panel will send a +12 volt signal to turn the master relay on. The master relay supplies power to the breaker/ fuse panel for the solenoid valves and to the pump relay. C:\0_Web\ml57000(SchoolTech)\ml doc Page 8 of 56 Revised: 15MAY16

9 If the vehicle has kick-down jacks, Push the AUTOMATIC LEVELING/RETRACT switch to AUTOMATIC LEVELING The red Automatic Leveling light will start to flash. The panel will send ground signals to the pump transistor on the breaker/fuse panel and to the horizontal/vertical valve. The pump will push fluid through the horizontal/vertical valve to all four jack actuators at the same time. The jacks will swing to the vertical position. There is no set order that the jacks go vertical. As a jack swings vertical, the jack warning switch sends a ground to the control panel to turn the appropriate red warning light on. When the control panel sees a ground from the 3000 psi manifold pressure switch, the panel will turn the pump and the horizontal/vertical valve off. The red Automatic Leveling light will stop flashing and remain on steady. Push the AUTOMATIC LEVELING/RETRACT switch to AUTOMATIC LEVELING a second time. The red Automatic Leveling light will start flashing. If the vehicle is equipped with an HWH air dump system, the air will dump from the suspension at this time. Depending on the program, the system will dump air for approximately 30 seconds. (If the system does not have an air dump system, the leveling procedure will start when the switch is pushed to AUTOMATIC LEVELING.) The system will start to level the vehicle according to lit yellow level lights. Different panels have different leveling programs. Normally, the system will extend jacks to turn lit rear lights off first. Some systems will operate two jacks at the same time, depending on lit level lights. When all four yellow level lights are out, the system will pause briefly then automatically go into the stabilize procedure. The stabilize procedure is a timed sequence. That means the pump will run for a specific amount of time then shut off. There are different times for different systems. The stabilize procedure will be 20 seconds for a vehicle without an HWH air dump system, ten seconds for a vehicle with an HWH air dump system and 60 seconds for a Blue Bird motor home with straight-acting jacks. During the stabilize procedure, the panel will send a ground signal to the pump transistor on the breaker/fuse panel and to the stabilize valve. Individual jack valves DO NOT open. When the stabilize valve is open, fluid is directed through the stabilize valve, then through the individual jack check valves out to the jacks that need to be extended. Fluid is also directed to a pressure reducing valve. This lowers the pressure available to extend jacks to approximately 250 to 350 psi. Jacks on the ground under pressure, will not extend. The check valves keep the jacks under pressure from retracting. Jacks not under pressure will extend until the system pressure allowed by the pressure reducing valve is reached. When the stabilize timer is done, the red Automatic Leveling light will shut off and the red System On light will turn off. Systems with the two position ON/OFF switch will remain on until the switch is turned off. If the vehicle has straight-acting jacks, review the automatic leveling sequence for kick-down jacks starting with Push the AUTOMATIC LEVELING/RETRACT switch to AUTOMATIC LEVELING a second time. At this point, the procedure is the same for both systems. Automatic retract: The ignition key must be on and the park brake should be set. The 400 Series systems do not use a park brake signal to inhibit system operation. Note: If the vehicle has an air suspension, it is best to start the vehicle engine at this time to build up air pressure. Push the ON/OFF paddle switch to the on position. The red system on light should come on. The panel will send a +12 volt signal to turn the master relay on. The master relay supplies power to the breaker/ fuse panel for the solenoid valves and to the pump relay. Push the AUTOMATIC LEVELING/RETRACT switch to AUTOMATIC RETRACT. The red Automatic Retract light will start to flash. The pump DOES NOT run during the retract procedure. The control panel will send a ground signal to all of the individual jack solenoid valves. The panel will also send a ground signal to the horizontal/vertical valve if the system is equipped with kick-down jacks. The jack springs will retract the cylinders, forcing the fluid back to the pump. If the vehicle is equipped with kick-down jacks, the springs will pull the jacks to the horizontal position as the foot of the jack clears the ground. If the system has straight-acting jacks, the jack warning switch contacts will open when the jack is within one to two inches of being fully retracted. The red jack down warning light will go out. If the system has kickdown jacks, the jack down warning switch contacts will open after the jack swings back to the horizontal position. The red jack down warning light will go out. The 400 Series systems have a timed automatic retract procedure. The procedure time is four minutes from when the AUTOMATIC LEVELING/RETRACT switch is pushed to AUTOMATIC RETRACT. At the end of the four minute time, the red Automatic Retract light will go out and the red System On light will go out. Systems with the two position ON/OFF switch will remain on until the switch is turned off. C:\0_Web\ml57000(SchoolTech)\ml doc Page 9 of 56 Revised: 15MAY16

10 Additional information for the 400 Series systems Excess Slope: Excess slope is when one or two jacks become fully extended with their yellow level lights remaining on. There is no indicator light for excess slope. When a jack becomes fully extended and its level light stays on, the pressure in the system will build up until the 3000 psi manifold pressure switch turns on. This sends a ground signal to the control panel. The processor will immediately turn the pump and any open jack solenoid valves off. After a several second delay, the system will go to the stabilize procedure and turn off after completing the stabilize procedure. Low Volts: Some paddle switch panels are equipped with a red LOW VOLTS lens on the bottom of the ON/OFF paddle switch. This light will come on if the voltage on the red and white twisted pair of wires going to the panel drops below approximately 8.5 volts. The system may continue to function but should be turned off if the LOW VOLTS light turns on. Low voltage can damage some of the system components. Master warning light: Most vehicles will have a master JACKS DOWN warning light that will be on anytime one or more individual paddle switch panel red jack down warning lights are on. The master warning light is controlled with a switched ground from the paddle switch panel. Power for the light is usually supplied by the paddle switch panel. C:\0_Web\ml57000(SchoolTech)\ml doc Page 10 of 56 Revised: 15MAY16

11 CORPORATION R CORPORATION CORPORATION R CHAPTER SERIES PADDLE SWITCH-CONTROL BI-AXIS SYSTEMS The 400 Series Paddle Switch-Control BI-AXIS system was used mainly on the larger Holiday Rambler motor homes that were equipped with an air suspension. There were other coaches that used this system. The standard paddle switch system panel and the BI-AXIS paddle switch system panel are very similar except for the wording around the manual jack control switches. Refer to CHAPTER 2, Figure 1 or Figure 2 for a view of the standard paddle switch panel. Figure 6 below shows the BI-AXIS panels. MASTER ON HW R H LEVEL EMERGENCY STORE MASTER ON AUTOMATIC LEVELING HORIZONTAL HWH OFF MASTER ON AUTOMATIC LEVELING MANUAL OPERATION HORIZONTAL LOW VOLT 5 AMP EMERGENCY AUTOMATIC VERTICAL OFF RETRACT MANUAL OPERATION CAUTION! BLOCK FRAME SECURELY BEFORE CHANGING TIRES OR WORKING UNDER VEHICLE. MANUAL USE LIMITED TO 4 MIN. WITHOUT COOL DOWN SWITCHES & LEVELEZE INDICATORS LEFT SIDE FRONT RIGHT SIDE REAR RETRACT RETRACT RETRACT EMERGENCY AUTOMATIC VERTICAL OFF RETRACT 5 AMP HWH CAUTION! BLOCK FRAME SECURELY BEFORE CHANGING TIRES OR WORKING UNDER VEHICLE. MANUAL USE LIMITED TO 4 MIN. WITHOUT COOL DOWN SWITCHES & LEVELEZE INDICATORS LEFT SIDE FRONT RIGHT SIDE REAR RETRACT RETRACT RETRACT HOLD HOLD HOLD HOLD HOLD HOLD EXTEND EXTEND EXTEND LEFT REAR LEFT FRONT RIGHT FRONT RIGHT REAR JACK DOWN INDICATORS EXTEND EXTEND EXTEND LEFT REAR LEFT FRONT RIGHT FRONT RIGHT REAR JACK DOWN INDICATORS Figure 6 Review CHAPTER 2 for a detailed discussion of the 400 Series systems. Because the components of both systems are very much alike, the same in most cases, and the two systems are operationally much the same, only the differences in the two systems will be discussed in this chapter. 3-1 Electrical Component Functions There are virtually no differences in the two systems electrically. The control panel for both systems is wired the same. The only difference in the two panels besides the visible difference of the panel lexan, is the individual jack control switches operate two jacks at the same time instead of one at a time. All of the system components, except the level sensing unit, such as valves, warning switches, pressure switch, master and pump relays, the breaker/fuse panel and the pump work the same for both systems. The repair part numbers for the individual parts are the same. One small difference is the breaker/fuse panel does not mount to the hydraulic manifold as it does on a standard 400 Series manifold. It is mounted separate from the manifold but must be mounted very close to the manifold mounting location. The grounding requirements for all of the components are the same. Like the standard 400 system, proper grounding of components is critical for the proper operation and maintenance of the 400 Series BI-AXIS systems. Level sensing unit: The level sensing unit for a 400 Series BI-AXIS system is electrically the same as a standard 400 Series level sensing unit. Like the standard system, the sensing unit switches a ground to turn the control panel yellow level lights on. BUT, it is mounted with a different orientation. The BI-AXIS sensing unit mounting sticker looks the same but the switches in the sensing unit are now orientated to indicate the front, rear, left side or right side low instead of corners of the vehicle. Like the standard 400 system sensing unit, the BI-AXIS sensing unit has a shielding cable that is grounded at the sensing unit. BI-AXIS SENSING UNIT MOUNTING SURFACE Figure 7 REAR THIS SIDE UP C:\0_Web\ml57000(SchoolTech)\ml doc Page 11 of 56 Revised: 15MAY16

12 3-2 Hydraulic Component Functions The 400 Series BI-AXIS leveling system incorporates the same style leveling jacks and hydraulic pump that the standard 400 Series system uses except the BI-AXIS system was only available with kick-down style jacks. Although the same valve functions were used on the BI-AXIS hydraulic manifold, the manifold arrangement was totally different. Like the standard manifold the BI- AXIS manifold had a shuttle valve to isolate the pressure side of the manifold from the return side, 4 jack solenoid valves; one valve for each jack, a horizontal/vertical valve for the kick-down procedure, a bleed valve to keep the jacks in the horizontal position while traveling, a stabilize valve and a pressure reducing valve for stabilizing the vehicle after the leveling procedure was complete. The manifold also has a 3000 psi pressure switch for the kick-down procedure and for the indication of excess slope. The four jack valves, the horizontal/vertical valve, and the stabilize valve are all the same part number valve and are interchangeable with each other and also with the valves on a standard 400 Series system. Although they perform the same function for both systems, the shuttle valve and the bleed valve are different from the standard system valves and are not interchangeable. The pressure reducing valve and the 3000 psi pressure switch are the same for both systems. The biggest difference between the two styles of hydraulic manifolds is the check valve arrangement. The standard 400 Series manifold had one check valve for each jack and was only used for stabilizing the vehicle. The BI-AXIS hydraulic manifold had 2 check valves for each jack, an inner check valve and an outer check valve. RIGHT REAR HOR.-VERT. RIGHT FRONT STABILIZE Figure 8 LEFT FRONT LEFT REAR The check valve arrangements in the BI-AXIS manifold are necessary for the leveling procedure and the stabilizing procedure. During leveling, two valves may be opened at the same time. During the stabilizing procedure, all four jack solenoid valves are open. The check valve arrangements prevent higher pressure fluid flowing from a jack that is extended to a jack that is not extended. This keeps the vehicle from dropping during a leveling or stabilizing procedure. The outer check valve can be accessed simply by removing the check valve cap. The inner check valve is directly below the outer check valve but is on the other side of the solenoid valve seat. The solenoid valve must be removed to access the inner check valve. Except for the pressure connection from the pump, the hose connections are not shown in Figure 8 and are on the back side of the manifold. There are two hydraulic hoses for each jack, one for the kickdown actuator and one for the main jack cylinder. All four jack actuator hoses tee together and are routed to one fitting on the manifold. Each hose for the main jack cylinders has its own fitting on the manifold. The schematics in Figure 9 and Figure 10 on the following page are for the 400 Series standard and BI- AXIS systems. These schematics show how the two systems differ hydraulically. C:\0_Web\ml57000(SchoolTech)\ml doc Page 12 of 56 Revised: 15MAY16

13 Figure 9 to the right shows a 400 Series standard manifold. Notice the four check valves are on a different circuit than the jack solenoid valves. If everything is working correctly, the only time the check valves are relevant, is when the system is in the stabilize mode. A diagnostic difference between the 400 standard system and not only the 400 Series BI-AXIS system but all BI- AXIS automatic hydraulic leveling systems is when a jack will not stay extended. With the standard system, a solenoid valve or check valve with an internal leak would cause a jack to retract when the system is inactive. With a BI-AXIS system, only a solenoid valve with an internal leak would cause this problem. A check valve that is leaking would not allow a jack to retract when the solenoid valve is closed. M PRESSURE RETURN SHUTTLE SOLENOID S MAIN HYDRAULIC SOLENOID MANIFOLD ASSEMBLY MAIN JACK CYLINDER RETURN PRESSURE BLEEDER CHECK S RELIEF (ADJUSTABLE ON SOME UNITS) + 12 VOLT DC HYDRAULIC POWER UNIT HORIZONTAL VERTICAL SOLENOID STABILIZING SOLENOID LR LF RF RR LEFT REAR LEFT FRONT Figure 9 RIGHT FRONT RELIEF ELECTRICAL PRESSURE SWITCH RIGHT REAR ACTUATOR C:\0_Web\ml57000(SchoolTech)\ml doc Page 13 of 56 Revised: 15MAY16

14 Figure 10 shows the 400 Series BI-AXIS manifold. Note the difference in the check valve arrangements between the two manifolds. The BI-AXIS manifold has two check valves for each solenoid valve. The check valves are on the same hydraulic circuit as the jack solenoid valves and are in the circuit before the solenoid valves. This schematic shows that, other than visible oil leaks, only a solenoid valve with an internal leak will cause a jack to retract when the system is inactive. The hydraulic circuits for the horizontal/vertical valve along with the bleed valve and the stabilize valve with the pressure reducing valve are virtually the same for both systems. The only difference in those circuits is the standard bleed valve is internally mounted and the BI- AXIS bleed valve is externally mounted. M 12 VOLT D.C. HYDRAULIC POWER UNIT RETURN CHECK INNER CHECK OUTER MAIN HYDRAULIC SOLENOID MANIFOLD ASSEMBLY *THE FLOW SWITCH FEATURE IS NOT USED ON PADDLE SWITCH BI-AXIS SYSTEM OR ON SOME TOUCH PANEL SYSTEMS. PRESSURE/ RETURN SHUTTLE 3-PORT DRAIN SOLENOID LR RELIEF (ADJUSTABLE ON SOME UNITS) PRESSURE STABILIZING SOLENOID SOLENOID LF *RELIEF /FLOW SWITCH SOLENOID RF ACTUATOR LEFT FRONT Figure 10 LEFT REAR RIGHT FRONT RIGHT REAR HORIZONTAL/ VERTICAL SOLENOID SOLENOID RR BLEEDER ELECTRICAL PRESSURE SWITCH HORIZONTAL/ VERTICAL ACTUATOR LINE MAIN JACK CYLINDERS 3-3 How the 400 Series BI-AXIS Leveling System Works Manual or Automatic Operation Review SECTION 2-3 and SECTION 2-4 of CHAPTER 2 in this lesson for complete operating information about the 400 Series BI-AXIS leveling system. The only difference between the standard 400 Series system and the BI-AXIS 400 Series system is the operation of two jacks at a time for leveling. Putting kick-down jacks in the vertical position, manual or automatic, is the same for both systems, air dump procedures are the same for both systems, excess slope is the same for both systems except the BI- AXIS system will almost always have at least two jacks fully extended to go into an excess slope situation, and all electrical functions such as jack down warning switches, the level sensing unit and the relays on the pump function the same for both systems. For manual leveling, the yellow indicator lights and the jack control paddle switches function in a BI- AXIS manner. Looking at the control panel from left to right, the switches and lights are labeled; LEFT SIDE FRONT RIGHT SIDE REAR. A lit yellow level light means that side or end of the vehicle is low instead of corners. The manual paddle switches operate the same as the lights are labeled. Pushing the LEFT SIDE switch extends or retracts the left front and left rear jacks at the same time. Pushing the FRONT switch extends or retracts the left front and right front jacks at the same time. Pushing the RIGHT SIDE switch extends or retracts the right front and right rear jacks at the same time. Pushing the REAR switch extends or retracts the right rear and left rear jacks at the same time. If manually leveling the vehicle, the operation for the BI-AXIS system is the same as the standard system; use paddle switches corresponding to lit yellow lights to extend jacks to put those yellow lights out. Extend jacks to turn off lit side lights to level the vehicle side to side before leveling the vehicle front to rear. When stabilizing a BI- AXIS leveling system, we recommend using the FRONT paddle switch if a front jack needs to be extended and use the REAR paddle switch if a rear jack needs to be extended, even if a front and rear jack on the same side need to be extended to stabilize the vehicle; don t use the LEFT SIDE or RIGHT SIDE paddle switches to stabilize the vehicle. For automatic leveling, except for operating two jacks at a time, there is no operational difference between the standard and BI-AXIS 400 Series leveling systems. The following is a quick review of the automatic procedure, refer to SECTION 2-4 of CHAPTER 2 for a detailed explanation of automatic operation. Push the Master On switch to ON. Push the Automatic Leveling/Retract switch to Automatic Leveling. The jacks will swing to the vertical position. Push the Automatic Leveling switch to Automatic C:\0_Web\ml57000(SchoolTech)\ml doc Page 14 of 56 Revised: 15MAY16

15 Leveling a second time, the system will level the vehicle according to the yellow level indicator lights then stabilize the vehicle when all yellow lights are out. The system will then shut off. Retracting jacks, automatic and manual. Review SECTION 2-3 and SECTION 2-4 of CHAPTER 2 for detailed information about retract procedures. Like leveling, there is very little difference between the two systems. With the BI-AXIS system, it is recommended to always use the FRONT and REAR paddle switches to manually retract the jacks. This will reduce twisting of the vehicle. C:\0_Web\ml57000(SchoolTech)\ml doc Page 15 of 56 Revised: 15MAY16

16 CHAPTER SERIES TOUCH PANEL/COMPUTER-CONTROL BI-AXIS SYSTEMS The 500 Series leveling system was the first HWH system to use a touch panel to control the system. The 500 Series leveling system was also used for more years than any other leveling system except the four lever manual leveling system. The 500 Series leveling system was introduced in 1988 and Country Coach used a version of this system until approximately late Although the electronics for touch panels have gone through many changes, the basic size and appearance of the touch panels used with current systems is not much different than the touch panels used for the 500 Series systems. The same template used to make a cutout for a 500 Series touch panel is used to make the cutout for the present day 725 Series leveling system. Unlike the 400 Series system that had the paddle switch panel which contained the control switches, indicator lights, processing components and the input and output connections, the 500 Series system has the touch panel which contains the control buttons and indicator lights but is connected to a control box that contains the processing components along with the input and output connections. The first 500 Series system was a combination system that could provide hydraulic leveling with jacks or air leveling using the vehicle s suspension air bags. The air leveling side of the system will be discussed in the next lesson, LESSON 14 Air Leveling System Identification and Operation. As you cover other chapters in this lesson, remember that these panels look the same as the panels used in the newer systems. They usually are not interchangeable with other panels. It is always important to get the correct touch panel. Some panels that look the same and even have the same panel connector are not interchangeable due to electronic differences such as being used in a 12 volt or 24 volt system. Figure 11 below shows some of the different touch panels used with the 500 Series system. HYDRAULIC LEVELING ONLY HYDRAULIC LEVELING WITH AIR DUMP HWH COMPUTERIZED LEVELING HWH COMPUTERIZED LEVELING CAUTION! CAUTION! HYDRAULIC OR AIR LEVELING AIR LEVELING ONLY HWH COMPUTERIZED LEVELING HWH COMPUTERIZED LEVELING CAUTION! CAUTION! Figure 11 C:\0_Web\ml57000(SchoolTech)\ml doc Page 16 of 56 Revised: 15MAY16