Installation

Instructions

CALIPER REPAIR KIT - HYDRAULIC DISC BRAKE

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IMPORTANT! PLEASE READ AND FOLLOW

THESE INSTRUCTIONS TO AVOID

PERSONAL INJURY OR DEATH:

When working on or around a vehicle, the following general precautions should be observed at all times.

1. Park the vehicle on a level surface, apply the parking brakes, and always block the wheels.

2. Stop the engine when working around the vehicle.

3. If the vehicle is equipped with air brakes, make certain to drain the air pressure from all reservoirs before beginning ANY work on the vehicle.

4. Following the vehicle manufacturer’s recommended procedures, deactivate the electrical system in manner that removes all electrical power from the vehicle.

5. When working in the engine compartment the engine should be shut off. Where circumstances require that the engine be in operation, EXTREME

CAUTION should be used to prevent personal injury resulting from contact with moving, rotating, leaking, heated, or electrically charged components.

6. Never connect or disconnect a hose or line containing pressure; it may whip. Never remove a component or plug unless you are certain all system pressure has been depleted.

7.

Never exceed recommended pressures and always wear safety glasses.

8.

Do not attempt to install, remove, disassemble or assemble a component until you have read and thoroughly understand the recommended procedures. Use only the proper tools and observe all precautions pertaining to use of those tools.

9.

Use only genuine Bendix replacement parts, components, and kits. Replacement hardware, tubing, hose, fittings, etc. should be of equivalent size, type, and strength as original equipment and be designed specifically for such applications and systems.

10. Components with stripped threads or damaged parts should be replaced rather than repaired.

Repairs requiring machining or welding should not be attempted unless specifically approved and stated by the vehicle or component manufacturer.

11. Prior to returning the vehicle to service, make certain all components and systems are restored to their proper operating condition.

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GENERAL

The procedures presented here are of a general nature and are intended as a guide to the installation of the parts contained in this kit. Complete brake maintenance and overhaul procedures are contained in the vehicle manufacturer's maintenance manual.

It is recommended that these instructions be thoroughly read as well as those presented in the vehicle maintenance manual before attempting to install this kit.

VEHICLE PREPARATION & CALIPER REMOVAL

1. Park the vehicle on a level surface and prevent movement by means other than the brakes.

2. Position the vehicle on floor stands and remove the appropriate wheel assemblies. Follow the procedures presented in the vehicle maintenance manual.

3. If the caliper piston(s) must be backed off to clear a worn rotor, check the fluid level of the master cylinder reservoir and remove as much as necessary to bring the level down to approximately one-third full.

4. Clean the exterior of the caliper assembly and hydraulic hose, removing all loose scale and grime. Inspect the hoses for deterioration and replace if necessary.

5. Disconnect the hydraulic hose(s) from the caliper and cap the lines to prevent fluid loss. Make certain to avoid getting grease or brake fluid on the disc pads.

6. Following the instructions presented in the vehicle maintenance manual, remove the caliper from the anchor plate. Remove the disc pads from the caliper assembly.

CALIPER DISASSEMBLY

1. Remove the piston or pistons from the caliper. (NOTE:

Some pistons incorporate boot shields which should be removed and discarded.) Air can be used to assist in piston removal however care MUST be taken to restrict piston travel and to prevent piston damage. A block of wood or shop towel can be used to accomplish this.

NOTE: On twin piston calipers it will be necessary to restrict the travel of BOTH pistons sufficiently to prevent one piston from clearing the caliper bore before the other.

IMPORTANT: Do not use excessive air pressure to remove the piston(s). If a piston appears seized or cocked and will not readily move, release the air pressure and using a soft mallet (non-steel) sharply rap on and around the end of the piston. Reapply air pressure to remove the piston. To avoid injury, keep hands away from the area between the piston(s) and piston stop.

Make certain to avoid brake fluid spray when applying compressed air to the caliper.

2. Remove the boot or boots from the caliper and discard.

3. Remove the seal or seals from the caliper and discard.

NOTE: Use a non-metallic tool when removing the seal(s) to avoid scratching the metal sealing surface.

CLEANING AND INSPECTION

1. Using a wire brush, remove rust and corrosion from the exterior of the caliper and anchor plate. Pay particular attention to rail surfaces of the caliper and anchor plate.

DO NOT USE A STEEL WIRE BRUSH TO CLEAN THE

CYLINDER BORE OR BOOT AND SEAL GROOVES.

2. Use a brass wire or fiber brush to remove all rust and foreign matter from the cylinder bore and seal and boot grooves.

3. Using fresh, clean brake fluid or denatured alcohol, clean the caliper housing and cylinder bore. Pay particular attention to the seal and boot grooves. Dry thoroughly before proceeding.

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4. Carefully examine the outer surface of the piston for scoring, nicks, corrosion and worn or damaged plating.

Replace if wear or damage is found.

REASSEMBLY

1. Place the caliper assembly on a clean work surface and with clean hands begin reassembly.

2. LIGHTLY LUBRICATE the new piston seal in clean brake fluid and install in the caliper groove. Avoid getting brake fluid in the boot groove. Make certain the seal is fully seated in the caliper groove.

3. If the piston incorporates a boot shield, install the new shield on the piston so that the shield is within approximately 1/16 of an inch (1.6 mm) from the outboard edge of the piston. A groove, large enough to accept the boot bead should be formed by the shield and piston body.

NOTE: The I.D. lip of the boot shield should face the outboard end of the piston.

4. LIGHTLY LUBRICATE the exterior of the piston with clean brake fluid.

5. Expand the boot and install it over the inboard end of the piston. Position the piston bead of the boot about 1 inch

(25.4 mm) from the inboard end of the piston. NOTE:

Avoid getting brake fluid on the caliper groove bead of the boot.

6. Locate the boot and piston over the caliper cylinder bore and work the boot bead into the caliper groove until it is entirely seated in the groove.

7. Gently push and work the piston into the cylinder bore while making certain not to dislodge the boot bead from its caliper groove. Once the piston is through the seal in the caliper, pull the boot bead up until it is in the piston groove. Push the piston into the caliper until it bottoms.

Check to make sure that boot is still firmly in the caliper groove by gently tugging on it.

8. Repeat Steps 2 thru 7 for twin piston calipers.

CALIPER INSTALLATION

1. Following the instructions presented in the vehicle maintenance manual, install the disc pads on the caliper assembly and mount the caliper on the anchor plate.

2. Reconnect the hydraulic hoses to the calipers making certain to avoid getting grease or brake fluid on the disc pads.

3. Thoroughly bleed the brake system following the instructions presented in the vehicle maintenance manual.

4. Check the master cylinder fluid level and fill as necessary with fresh, clean brake fluid of the type specified by the vehicle manufacturer.

5. Replace the wheels assemblies. Test the brakes prior to placing the vehicle in service.

S-897 © 2002 Bendix Commercial Vehicle Systems LLC 2/2002 Printed in U.S.A. All rights reserved.