Publication CB 00 GB CV Master Cylinders NOTE: This instruction describes the replacement and servicing procedures for the Carlisle range of CV Master Cylinder assemblies. Information contained in this publication is subject to change without notice or liability. WARNING: For optimum results and safety, Carlisle recommends that all work should be carried out by a suitably trained fitter/mechanic. If it is decided to replace used components or assemblies, always use genuine Carlisle replacement parts. If in doubt seek professional help. WARNING: Any defective master cylinder assembly must be replaced with a new genuine Carlisle assembly. brake oil systems. The system band attached to all units. BLACK ID bands GREEN ID bands indicate mineral brake oil contamination and premature failure of Brake Oil recommended by the vehicle CAUTION: Always ensure appropriate safety glasses and gloves are worn when carrying out the procedures detailed below. Typical Assembly 12 7 8 9 10 11 1 2 3 4 1 If printed this document is uncontrolled Copyright Carlisle Brake and Friction 2012
Park the vehicle on hard ground and chock the wheels. Follow the vehicle manufacturer s recommendations to gain access to the master cylinder. Ensure the parking brake is applied and no hydraulic pressure is held in the system. Clean any dirt or debris from the master cylinder assembly paying particular attention to the areas around the hydraulic connections. WARNING: If the areas around the hydraulic connections are not cleaned before the connections are removed there is a possibility that debris can enter the master cylinder hydraulic ports during the connection removal process. Any debris entering the hydraulic ports will compromise the master cylinder function and could lead to premature failure. Master Cylinder Removal NOTE: The orientation of the brake port and method of securing the master cylinder unit to the vehicle may vary due to different vehicle installations. Before removal note the orientation of the master cylinder assembly and position of the hydraulic pipework connection (Fig. 1) to aid re-assembly. CAUTION: Ensure any residue brake oil / brake fluid from the disconnected hydraulic pipe or master cylinder assembly is caught in a suitable container and/or wiped clean with a suitable cloth. Dispose of any residue brake oil or contaminated cloth in accordance with local environmental regulations. Drain the braking system of brake oil by attaching a rubber tube to a bleed screws, unscrew the bleed screw half a turn and pump out the brake oil/brake fluid into a suitable container by operating the foot pedal. Remove the hydraulic pipe connection/s from the master cylinder and carefully ease the hydraulic pipe/s clear of the master cylinder hydraulic port/s. Disconnect the push rod from the foot pedal linkage. Remove the nuts, or where applicable bolts, securing the master cylinder assembly to the vehicle bulkhead. Carefully remove the master cylinder assembly from the vehicle taking care to avoid spillage of any residual brake oil from the hydraulic ports or fluid reservoir. Dismantling Remove the dust excluder (1) from its location on the cylinder body. Slide the dust excluder along the pushrod (2), or peel back, to allow access to the circlip (4) in the mouth of the cylinder bore. Remove the circlip (4) and discard. Remove the dust excluder (1) from the pushrod and discard. Place the pushrod (2) and washer (3) aside in a clean area for re-use. Carefully shake out the plunger assembly, or tap the end of the cylinder on a soft wooden block to remove the plunger assembly (Fig 2). 2 Carefully lift the leaf (13) on the spring retainer (10) to dismantle the plunger assembly (Fig 3). Remove the spring washer (7) and seal () from the head of the valve stem (). Carefully remove the plunger seal (11) and discard (Fig 3). 12 3 11 13 9 CAUTION: Do not use any type of sharp implement to remove the valve stem seal () or plunger seal (11). Any damage to the seal location grooves on the valve stem head or plunger will prevent correct seal location and may lead to insufficient sealing and premature failure of components. 7 NOTE: If the cylinder assembly is to be serviced, this must be carried out in a clean environment.
Cleaning and Inspection Clean all parts which are to be re-used with new unused Brake Fluid or Brake Oil. Examine the plunger (12) and cylinder bore; if the surfaces are not in perfect condition, or there is any doubt in the suitability for further service, a new genuine Carlisle cylinder assembly must be fitted. Re-assembly Lightly lubricate the new plunger seal with unused Brake Fluid/Brake Oil and fit the new plunger seal (11) to the plunger (12). Lightly lubricate the new valve stem seal () with unused Brake Fluid/Brake Oil and fit the new spring washer (7) and seal () to the valve stem (), (Fig 3). Re-assemble the plunger assembly as shown in Fig 4. and carefully press down the leaf (13) in the spring retainer (10) to secure the plunger components together. 8 9 10 11 12 NOTE: if the spring (9) is cone shaped, the small end is fitted to the spring retainer (10). Lubricate the cylinder bore and plunger seal (11) with unused Brake Fluid/Brake Oil, before inserting the plunger assembly into the cylinder bore. Locate the pushrod (2) and washer (3) in the bore of the cylinder and retain with a new circlip (4). Smear the internal sealing areas of the new dust excluder (1) with rubber grease. CAUTION: Use only the grease recommended by the vehicle The use of any other grease could lead to contamination of the dust excluder and may lead to insufficient sealing and premature failure of components. Carefully slide the new dust excluder (1) over the push rod and fit the large diameter of the excluder correctly in to the location groove on the cylinder body. Ensure the dust excluder is securely located on the cylinder body. Master cylinder Assembly Fitment Fit the new master cylinder assembly to the vehicle bulkhead, in the correct orientation and secure with the retaining nuts/bolts. Tighten the fixings to the torque value recommended by the vehicle manufacturer NOTE: The brake pedal must be in the at rest position, held against the pedal backstop by the pedal return spring during pushrod connection/adjustment. Connect the push rods to the brake pedal linkage. Adjust the push rod/s at the pedal linkage following the recommendations of the vehicle NOTE: Ensure the brake pedal remains held against the pedal backstop when pushrod adjustment has been completed. Refit the hydraulic pipework connection/s to the hydraulic port/s on the master cylinder assembly (Fig. 1). Refer to the note made at master cylinder removal if necessary. Reference should be made to the following table for the correct tightening torque for each of the various hydraulic fittings and master cylinder retaining bolts or nuts. 4 7 13
Description Master cylinder Retaining Bolt / Nut Thread Specification Tightening Torque Refer to the vehicle manufacturers recommendations M12 x 1 H 20 24Nm M12 x 1. - H 20 24 Nm 9/1 18UNF - 3/8 24UNF - 7/1 20UNF - 23 27 Nm 7-10 Nm 20 24 Nm When the master cylinder assembly has been secured to the vehicle and the hydraulic connections made it is important to remove any air in the hydraulic system. Follow the bleeding procedure detailed below. Bleeding Procedure Attach a rubber tube to the right and left hand bleedscrews, unscrew the left hand bleed screw half a turn. Hydraulic Port Adaptor Replacement NOTE: There may be sufficient working access on certain installations which allow the hydraulic port adaptors to be replaced without the need to remove the cylinder assembly. If sufficient access is available disregard the cylinder removal and re-fitting detail contained in this publication. If there is any doubt regarding sufficient access, always remove the cylinder assembly following the Master Cylinder Removal section of this publication. Adaptor Removal Cylinders Fitted to the Vehicle Using a suitable hose clamp, clamp off the flexible rubber hose, close to the adaptor (14). Remove the flexible rubber hose from the adaptor. 14 Apply the brake pedal and fully stroke the cylinder push rod approximately twenty times to expel aerated brake oil from the cylinder unit into a suitable container. Tighten the bleedscrew. Ensure the oil/fluid level in the reservoir is kept at the correct level during the bleeding process. Repeat the procedure for the right hand bleedscrew. 1 Depending on the type of installation, the bleeding procedure, detailed above, may need to be repeated until all air has been expelled from the hydraulic system. CAUTION: Ensure any residue brake oil / brake fluid from the cylinder assembly is caught in a suitable container and/or wiped clean with a suitable cloth. Dispose of any residue brake oil or contaminated cloth in accordance with local environmental regulations. Check for fluid leaks at all disturbed hydraulic connections and rectify as necessary. Where applicable, refit the road wheels, remove the axle stands and lower the vehicle to the ground. Where applicable, refit the road wheels, remove the axle stands and lower the vehicle to the ground. All Cylinders Remove the adaptor (14) from the hydraulic port and discard (Fig ). WARNING: Ensure the hydraulic port is not damaged during the removal of the adaptor seal. Any damage could prevent correct fitment of the new adaptor and seal or lead to premature failure of the assembly. Carefully remove the adaptor seal (14) from the hydraulic port (Fig ). Compare the size of the adaptor seal removed from the cylinder with the new adaptor seal. DO NOT allow any contact between the used and new seal. If the new seal appears to be smaller than the used seal removed from the cylinder, this could indicate system fluid contamination. If there is any doubt in the suitability for further service, always replace the cylinder assembly with a new genuine Carlisle replacement. If printed this document is uncontrolled Copyright Carlisle Brake and Friction 2012
Adaptor Fitment 1 14 Lubricate the new adaptor seal (1) with new, unused brake fluid or brake oil to the correct specification. Carefully locate the new seal (1) correctly in the cylinder hydraulic adaptor port (Fig ). Lubricate the new adaptor (14) with new, unused brake fluid or brake oil to the correct specification. Carefully push the adaptor (14) through the adaptor seal (1), until it locates correctly (Fig ). Refit the cylinder assembly following the Master Cylinder Fitment section of this publication, or Cylinders Fitted to the Vehicle Refit the flexible rubber hose to the adaptor. Remove the hose clamp from the flexible rubber hose. Carlisle Brake Products (UK) Ltd. Omega 00 Unit, Mamhilad Technology Park, Pontypool, Torfaen, NP4 0JJ Tel: 0149 77300 Fax: 0149 77330 E-Mail: sales@carlislecbf.com