Transcript
TM
Dry Disc Park Brake Frein de parc à disque Maintenance Manual MM4A Manuel de maintenance MM4A
Models 1270, 1286 and 1287 Modèles 1270, 1286 et 1287
Issued 04-03 Edité Avril-03
Service Notes Service Notes Before You Begin
This manual provides instructions for AxleTech International’s models 1270, 1286 and 1287 dry disc park brakes. Before you begin procedures: 1.
Read and understand all instructions and procedures before you begin to service components.
2.
Read and observe all Caution and Warning safety alerts that precede instructions or procedures you will perform. These alerts help to avoid damage to components, serious personal injury, or both.
3.
Follow your company’s maintenance and service, installation, and diagnostics guidelines.
4.
Use special tools when required to help avoid serious personal injury and damage to components.
Safety Alerts, Torque Symbol and Notes A Warning alerts you to an
WARNING instruction or procedure that you must follow exactly to avoid serious personal injury.
CAUTION
A Caution alerts you to an instruction or procedure that you must follow exactly to avoid damage to components. A torque symbol alerts you to tighten fasteners to a specified torque value.
NOTE
A Note provides information or suggestions that help you correctly service a component.
The instructions contained in this Field Maintenance Manual are intended for use by skilled and experienced mechanics knowledgeable in the installation, repair and replacement of AxleTech dry disc park brakes. Installation, maintenance and replacement of AxleTech dry disc brakes require a high degree of skill and experience. The consequences of improper installation, maintenance or replacement are grave and can result in brake failure and resulting loss of control of the vehicle and possible injury to or death of persons. AxleTech does not authorize anyone other than highly skilled and experienced individuals to attempt to utilize the instructions contained in this Manual for the installation, maintenance or replacement of AxleTech dry disc brakes and AxleTech shall have no liability of any kind for damages arising out of (or in connection with) any other use of the information contained in this Manual.
Table of Contents Table of Contents
Asbestos and Non-Asbestos Fibers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i Exploded View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Section 1: Introduction Brake Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Section 2: Component Replacement Brake Pads Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Seal Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Caliper Assembly Installation
Section 3: Maintenance and Inspection Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Inspect Parts Linings Caliper
Section 4: Prepare Parts for Assembly Clean, Dry and Inspect Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Clean Parts Dry and Inspect Parts Apply Corrosion Protection
Section 5: Adjustments Brake Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Parking Brake Emergency Release Bleed Brake
Section 6: Specifications Hydraulic Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Hydraulic Pressure Seal Kit MPS4646
Notes
Asbestos and Non-Asbestos Fibers ASBESTOS FIBERS WARNING
NON-ASBESTOS FIBERS WARNING
The following procedures for servicing brakes are recommended to reduce exposure to asbestos fiber dust, a cancer and lung disease hazard. Material Safety Data Sheets are available from AxleTech.
The following procedures for servicing brakes are recommended to reduce exposure to non-asbestos fiber dust, a cancer and lung disease hazard. Material Safety Data Sheets are available from AxleTech.
Hazard Summary
Hazard Summary
Because some brake linings contain asbestos, workers who service brakes must understand the potential hazards of asbestos and precautions for reducing risks. Exposure to airborne asbestos dust can cause serious and possibly fatal diseases, including asbestosis (a chronic lung disease) and cancer, principally lung cancer and mesothelioma (a cancer of the lining of the chest or abdominal cavities). Some studies show that the risk of lung cancer among persons who smoke and who are exposed to asbestos is much greater than the risk for non-smokers. Symptoms of these diseases may not become apparent for 15, 20 or more years after the first exposure to asbestos. Accordingly, workers must use caution to avoid creating and breathing dust when servicing brakes. Specific recommended work practices for reducing exposure to asbestos dust follow. Consult your employer for more details.
Most recently manufactured brake linings do not contain asbestos fibers. These brake linings may contain one or more of a variety of ingredients, including glass fibers, mineral wool, aramid fibers, ceramic fibers and silica that can present health risks if inhaled. Scientists disagree on the extent of the risks from exposure to these substances. Nonetheless, exposure to silica dust can cause silicosis, a non-cancerous lung disease. Silicosis gradually reduces lung capacity and efficiency and can result in serious breathing difficulty. Some scientists believe other types of non-asbestos fibers, when inhaled, can cause similar diseases of the lung. In addition, silica dust and ceramic fiber dust are known to the State of California to cause lung cancer. U.S. and international agencies have also determined that dust from mineral wool, ceramic fibers and silica are potential causes of cancer. Accordingly, workers must use caution to avoid creating and breathing dust when servicing brakes. Specific recommended work practices for reducing exposure to non-asbestos dust follow. Consult your employer for more details.
Recommended Work Practices 1. Separate Work Areas. Whenever feasible, service brakes in a separate area away from other operations to reduce risks to unprotected persons. OSHA has set a maximum allowable level of exposure for asbestos of 0.1 f/cc as an 8-hour time-weighted average and 1.0 f/cc averaged over a 30-minute period. Scientists disagree, however, to what extent adherence to the maximum allowable exposure levels will eliminate the risk of disease that can result from inhaling asbestos dust. OSHA requires that the following sign be posted at the entrance to areas where exposures exceed either of the maximum allowable levels: DANGER: ASBESTOS CANCER AND LUNG DISEASE HAZARD AUTHORIZED PERSONNEL ONLY RESPIRATORS AND PROTECTIVE CLOTHING ARE REQUIRED IN THIS AREA. 2. Respiratory Protection. Wear a respirator equipped with a high-efficiency (HEPA) filter approved by NIOSH or MSHA for use with asbestos at all times when servicing brakes, beginning with the removal of the wheels. 3. Procedures for Servicing Brakes. a. Enclose the brake assembly within a negative pressure enclosure. The enclosure should be equipped with a HEPA vacuum and worker arm sleeves. With the enclosure in place, use the HEPA vacuum to loosen and vacuum residue from the brake parts. b. As an alternative procedure, use a catch basin with water and a biodegradable, non-phosphate, water-based detergent to wash the brake drum or rotor and other brake parts. The solution should be applied with low pressure to prevent dust from becoming airborne. Allow the solution to flow between the brake drum and the brake support or the brake rotor and caliper. The wheel hub and brake assembly components should be thoroughly wetted to suppress dust before the brake shoes or brake pads are removed. Wipe the brake parts clean with a cloth. c. If an enclosed vacuum system or brake washing equipment is not available, employers may adopt their own written procedures for servicing brakes, provided that the exposure levels associated with the employer’s procedures do not exceed the levels associated with the enclosed vacuum system or brake washing equipment. Consult OSHA regulations for more details. d. Wear a respirator equipped with a HEPA filter approved by NIOSH or MSHA for use with asbestos when grinding or machining brake linings. In addition, do such work in an area with a local exhaust ventilation system equipped with a HEPA filter. e. NEVER use compressed air by itself, dry brushing, or a vacuum not equipped with a HEPA filter when cleaning brake parts or assemblies. NEVER use carcinogenic solvents, flammable solvents, or solvents that can damage brake components as wetting agents. 4. Cleaning Work Areas. Clean work areas with a vacuum equipped with a HEPA filter or by wet wiping. NEVER use compressed air or dry sweeping to clean work areas. When you empty vacuum cleaners and handle used rags, wear a respirator equipped with a HEPA filter approved by NIOSH or MSHA for use with asbestos. When you replace a HEPA filter, wet the filter with a fine mist of water and dispose of the used filter with care. 5. Worker Clean-Up. After servicing brakes, wash your hands before you eat, drink or smoke. Shower after work. Do not wear work clothes home. Use a vacuum equipped with a HEPA filter to vacuum work clothes after they are worn. Launder them separately. Do not shake or use compressed air to remove dust from work clothes. 6. Waste Disposal. Dispose of discarded linings, used rags, cloths and HEPA filters with care, such as in sealed plastic bags. Consult applicable EPA, state and local regulations on waste disposal.
Regulatory Guidance References to OSHA, NIOSH, MSHA, and EPA, which are regulatory agencies in the United States, are made to provide further guidance to employers and workers employed within the United States. Employers and workers employed outside of the United States should consult the regulations that apply to them for further guidance.
Maintenance Manual MM-4A Issued 04-03
Recommended Work Practices 1. Separate Work Areas. Whenever feasible, service brakes in a separate area away from other operations to reduce risks to unprotected persons. 2. Respiratory Protection. OSHA has set a maximum allowable level of exposure for silica of 0.1 mg/m3 as an 8-hour time-weighted average. Some manufacturers of non-asbestos brake linings recommend that exposures to other ingredients found in non-asbestos brake linings be kept below 1.0 f/cc as an 8-hour time-weighted average. Scientists disagree, however, to what extent adherence to these maximum allowable exposure levels will eliminate the risk of disease that can result from inhaling non-asbestos dust. Therefore, wear respiratory protection at all times during brake servicing, beginning with the removal of the wheels. Wear a respirator equipped with a high-efficiency (HEPA) filter approved by NIOSH or MSHA, if the exposure levels may exceed OSHA or manufacturers’ recommended maximum levels. Even when exposures are expected to be within the maximum allowable levels, wearing such a respirator at all times during brake servicing will help minimize exposure. 3. Procedures for Servicing Brakes. a. Enclose the brake assembly within a negative pressure enclosure. The enclosure should be equipped with a HEPA vacuum and worker arm sleeves. With the enclosure in place, use the HEPA vacuum to loosen and vacuum residue from the brake parts. b. As an alternative procedure, use a catch basin with water and a biodegradable, non-phosphate, water-based detergent to wash the brake drum or rotor and other brake parts. The solution should be applied with low pressure to prevent dust from becoming airborne. Allow the solution to flow between the brake drum and the brake support or the brake rotor and caliper. The wheel hub and brake assembly components should be thoroughly wetted to suppress dust before the brake shoes or brake pads are removed. Wipe the brake parts clean with a cloth. c. If an enclosed vacuum system or brake washing equipment is not available, carefully clean the brake parts in the open air. Wet the parts with a solution applied with a pump-spray bottle that creates a fine mist. Use a solution containing water, and, if available, a biodegradable, non-phosphate, water-based detergent. The wheel hub and brake assembly components should be thoroughly wetted to suppress dust before the brake shoes or brake pads are removed. Wipe the brake parts clean with a cloth. d. Wear a respirator equipped with a HEPA filter approved by NIOSH or MSHA when grinding or machining brake linings. In addition, do such work in an area with a local exhaust ventilation system equipped with a HEPA filter. e. NEVER use compressed air by itself, dry brushing, or a vacuum not equipped with a HEPA filter when cleaning brake parts or assemblies. NEVER use carcinogenic solvents, flammable solvents, or solvents that can damage brake components as wetting agents. 4. Cleaning Work Areas. Clean work areas with a vacuum equipped with a HEPA filter or by wet wiping. NEVER use compressed air or dry sweeping to clean work areas. When you empty vacuum cleaners and handle used rags, wear a respirator equipped with a HEPA filter approved by NIOSH or MSHA, to minimize exposure. When you replace a HEPA filter, wet the filter with a fine mist of water and dispose of the used filter with care. 5. Worker Clean-Up. After servicing brakes, wash your hands before you eat, drink or smoke. Shower after work. Do not wear work clothes home. Use a vacuum equipped with a HEPA filter to vacuum work clothes after they are worn. Launder them separately. Do not shake or use compressed air to remove dust from work clothes. 6. Waste Disposal. Dispose of discarded linings, used rags, cloths and HEPA filters with care, such as in sealed plastic bags. Consult applicable EPA, state and local regulations on waste disposal.
Regulatory Guidance References to OSHA, NIOSH, MSHA, and EPA, which are regulatory agencies in the United States, are made to provide further guidance to employers and workers employed within the United States. Employers and workers employed outside of the United States should consult the regulations that apply to them for further guidance.
Copyright 2003 AxleTech International
Page i
Notes
Exploded View Exploded View
2 19
14
20
5
21
4
22 15
23
6
24
17
18
3 9
7
16 12
13
8 10
1
11
25
26
Item 1 2 3 4 5 6 7 8 9 10 11 12 13
Description Housing Large Snap Ring Pressure Ring Piston Screw Cap Slide Pin Retainer Ring Dust Boot Brake Pad Friction Sleeve Magnet Cup Seal Cup Seal
Maintenance Manual MM-4A Issued 04-03
Item 14 15 16 17 18 19 20 21 22 23 24 25 26
Copyright 2003 AxleTech International
Description Adjusting Screw Lock Nut Nut Cotter Pin O-Ring Seal O-Ring Seal O-Ring Seal Cup Spring Wear Plate Thrust Bolt Bleeder Screw Washer Inlet Adapter
Page 1
Section 1 Introduction Section 1 Introduction Brake Operation
The two brake pads slide on the guide bolts in the housing. When the brake is actuated, the cup springs move the piston, adjusting screw, thrust bolt and inner brake pad toward the brake disc. When the inner brake pad contacts the brake disc, the housing shifts onto the guide bolts and the outer brake pad is pressed against the brake disc also. The brake is released by hydraulic pressure. When the brake is released, the piston compresses the cup springs, pulling the inner brake pad away from the brake disc. Brake lining and brake disc wear reduces braking force. The brake must be adjusted to maintain braking force. Refer to Section 5. When replacing parts, only use factory original parts and parts sets. Parts must be ordered through the vehicle manufacturer. Any damage to parts not described in this manual must be repaired or replaced using original parts.
Page 2
Copyright 2003 AxleTech International
Maintenance Manual MM-4A Issued 04-03
Section 2 Component Replacement 5.
Section 2 Replacement Component
WARNING To prevent serious eye injury, always wear safe eye protection when you perform vehicle maintenance or service. Park the vehicle on a level surface. Block the wheels to prevent the vehicle from moving. Support the vehicle with safety stands. Do not work under a vehicle supported only by jacks. Jacks can slip and fall over. Serious personal injury and damage to components can result.
NOTE: You only need to remove one of the two guide bolts to remove the brake pads from the housing. 6.
Remove a guide bolt cotter pin. Unscrew the castellated nut. Pull the guide bolt out of the brake housing.
7.
Remove the brake pads from the brake housing in the direction of the removed guide bolt.
8.
If there is not enough clearance to replace the brake pads, the brake housing must be completely removed.
When the parking brake is released, the vehicle does not have any park brake function. You must block the wheels to prevent the vehicle from moving. Serious personal injury and damage to components can result.
A. If the hydraulic pressure hose is too short to remove the brake, you must release the pressure and disconnect the hose. Perform the parking brake emergency release procedure before you remove the brake. Refer to Section 5.
Brake Pads Replacement
B. Pull both guide bolts out of the brake housing to remove the housing.
CAUTION Always replace both linings with specified parts. If you only replace one lining, damage to the disc can occur. If you use non-AxleTech parts, incorrect brake operation can occur. Damage to components can result. Brake lining thickness must be inspected at regular intervals, depending on vehicle usage. Inspect the lining thickness every six months minimum. Use the following procedure to replace the linings if lining thickness reaches: 0.04-inch (1.0 mm) or less for model 1270 brake. 0.08-inch (2.0 mm) or less for models 1286 and 1287 brakes. 1.
Park the vehicle on a level surface. Block the wheels to prevent the vehicle from moving. If it is necessary to raise the vehicle to service the parking brake, use a jack to raise the vehicle. Support the vehicle with safety stands.
2.
Apply 1450 psi (100 bar) of hydraulic pressure to release the parking brake.
3.
Remove the screw cap.
4.
Loosen the lock nut. Use a male hex wrench, M8 for model 1270 brake or M10 for models 1286 and 1287 brakes, to turn the adjusting screw counterclockwise.
Maintenance Manual MM-4A Issued 04-03
Use a screwdriver to push the inner pad away from the brake disc to create clearance for the new brake pads.
9.
Install new brake pads. Insert the guide bolts into the brake housing. Check the permanent magnets to verify that they have enough magnetic force to hold the brake pads. If the permanent magnets do not have enough magnetic force to hold the brake pads: Replace the magnets. Use a screwdriver to pry the magnets from the outer end of the thrust bolt and caliper boss.
10. Secure the guide bolts with the castellated nut and cotter pin. 11. If you completely removed the brake, connect the pressure hose and bleed the brake. 12. Before you return the vehicle to service, adjust the brake using the procedure in Section 5.
Copyright 2003 AxleTech International
Page 3
Section 2 Component Replacement Seal Replacement NOTE: See Section 6 for contents of Seal Kit MPS4646.
10. Use a suitable tool with rounded edges to install the new piston seals. Take care to avoid damage to the sealing lips.
1.
Park the vehicle on a level surface. Block the wheels to prevent the vehicle from moving.
11. Use a suitable seal driver and a screw-type clamp to press a new dust cap into the housing.
2.
Apply 1450 psi (100 bar) of hydraulic pressure to release the parking brake.
3.
Remove the screw cap.
4.
Loosen the lock nut. Use a male hex wrench, M8 for model 1270 brake or M10 for models 1286 and 1287 brakes, to turn the adjusting screw counterclockwise until the adjusting screw extends 1.1-1.2-inches (27-30 mm) outside of the piston.
5.
Release hydraulic pressure. Remove the pressure hose and completely remove the brake.
6.
Remove the large snap ring. Remove the pressure ring from the housing.
7.
Remove the cup springs, piston and thrust bolt. Maintain cup spring orientation.
8.
Remove the piston seals.
9.
Use a suitable tool to pry out the dust cap.
12. Use silicone grease, Dow Corning DC-4 or equivalent, to lightly grease the sliding and sealing surfaces of the piston. 13. Install the piston and thrust bolt assembly. Install the dust cap lip into the thrust bolt groove. 14. Install the cup springs in the original orientation. Figure 2.1. 15. Install the pressure ring into the housing. Install the large snap ring. 16. Mount the caliper on the axle adapter using the procedure in this section.
Caliper Assembly Installation NOTE: Install the caliper assembly when the brake is cold.
CAUTION You must mount the piston seals in the direction shown in Figure 2.1. I ncorrect mounting can result in leakage and loss of pressure.
1.
Park the vehicle on a level surface. Block the wheels to prevent the vehicle from moving.
2.
Remove the screw cap.
3.
Loosen the lock nut. Use a male hex wrench, M8 for model 1270 brake or M10 for models 1286 and 1287 brakes, to turn the adjusting screw counterclockwise.
4.
Push the inner brake pad and pressure bolt assembly toward the caliper head to create a larger opening between the brake pads.
5.
Install the caliper assembly onto the brake disc and fasten it to the axle adapter.
6.
Install a hydraulic pressure line to the caliper inlet fitting. Apply 1450 psi (100 bar) of pressure. The piston will retract and the cup springs will be pre-tensioned.
7.
Before you return the vehicle to service, adjust the brake using the procedure in Section 5.
8.
Bleed all air from the piston chamber. See Bleed Brake in Section 5.
Figure 2.1 1
2
5
3 4
1 2 3 4 5
CUP SPRINGS LARGE SNAP RING PRESSURE RING PISTON SEALS DUST CAP
Page 4
Copyright 2003 AxleTech International
Maintenance Manual MM-4A Issued 04-03
Section 3 Maintenance and Inspection Caliper
Section 3 Maintenance and Inspection
WARNING To prevent serious eye injury, always wear safe eye protection when you perform vehicle maintenance or service.
Maintenance The brake pads are maintenance-free. Check for damaged parts and verify that the brake disc operates correctly.
1.
Inspect for fluid leaks. Disassemble the caliper if there is a leak. Inspect the piston, piston bore and seals. Replace parts as necessary.
2.
Inspect the piston and housing bores for scratches and corrosion. Use a fine emery cloth to remove scratches or corrosion. Replace worn or damaged components. Replace components that are heavily corroded or have large scratches.
Inspect Parts Linings CAUTION Always replace both linings with specified parts. If you only replace one lining, damage to the disc can occur. If you use non-AxleTech parts, incorrect brake operation can occur. Damage to components can result. Brake lining thickness must be visually inspected at regular intervals, depending on vehicle usage. Inspect the lining thickness every six months minimum. 1.
Remove the linings. Inspect the linings for wear and damage. Replace damaged linings.
2.
Replace linings if you find the following conditions: If the lining thickness reaches: — 0.04-inch (1.0 mm) or less for model 1270 brake. — 0.08-inch (2.0 mm) or less for models 1286 and 1287 brakes. Each lining has a different thickness. The linings are contaminated with oil or grease. The linings have large or deep cracks. Small, tight cracks or heat checks on the lining’s surface, which are caused by high temperatures, are normal.
Maintenance Manual MM-4A Issued 04-03
Copyright 2003 AxleTech International
Page 5
Section 4 Prepare Parts for Assembly Dry and Inspect Parts
Section 4Parts for Assembly Prepare
WARNING To prevent serious eye injury, always wear safe eye protection when you perform vehicle maintenance or service.
Clean, Dry and Inspect Parts
1.
Use soft, clean paper or cloth rags or compressed air to completely dry parts immediately after you clean them.
2.
Carefully inspect all parts for wear or damage before you assemble them.
3.
Repair or replace worn or damaged parts.
Apply Corrosion Protection
WARNING Solvent cleaners can be flammable, poisonous and cause burns. Examples of solvent cleaners are carbon tetrachloride, and emulsion-type and petroleum-base cleaners. Read the manufacturer’s instructions before using a solvent cleaner, then carefully follow the instructions. Also follow the procedures below. Wear safe eye protection.
1.
Apply brake system hydraulic fluid to cleaned, dried parts. Be careful that you do not apply the grease to the linings or rotor.
2.
If you will store the parts, apply a special material, which prevents corrosion and rust, to all surfaces. Store parts inside special paper or other material that prevents rust and corrosion.
Wear clothing that protects your skin. Work in a well-ventilated area. Do not use gasoline, or solvents that contain gasoline. Gasoline can explode. You must use hot solution tanks or alkaline solutions correctly. Read the manufacturer’s instructions before using hot solution tanks and alkaline solutions. Then carefully follow the instructions.
Clean Parts CAUTION Do not use hot solution tanks or water and alkaline solutions to clean ground or polished parts. Damage to parts can result. 1.
Use a cleaning solvent or kerosene or diesel fuel to clean ground or polished metal parts or surfaces. Examples of ground or polished parts are the piston and the piston bore in the caliper.
2.
Use a wire brush to clean fastener and fitting threads.
3.
Remove mud and dirt on the linings. Replace all linings contaminated with oil or grease.
Page 6
Copyright 2003 AxleTech International
Maintenance Manual MM-4A Issued 04-03
Section 5 Adjustments 6.
Hold the adjusting screw in position. Tighten the lock nut securely.
To prevent serious eye injury, always wear safe eye protection when you perform vehicle maintenance or service.
7.
Install and hand-tighten the screw cap.
8.
Actuate the brake several times.
Park the vehicle on a level surface. Block the wheels to prevent the vehicle from moving. Support the vehicle with safety stands. Do not work under a vehicle supported only by jacks. Jacks can slip and fall over. Serious personal injury and damage to components can result.
9.
Check the parking brake on a slope.
Section 5 Adjustments
WARNING
When the parking brake is released, the vehicle does not have any park brake function. You must block the wheels to prevent the vehicle from moving. Serious personal injury and damage to components can result.
Brake Adjustment Brake adjustment is required after installing new brake pads or brake discs, after all repairs, and to improve braking performance. Adjust the brakes when the brake is cold. The park brake must be in the released condition during the adjustment procedure. 1.
Park the vehicle on a level surface. Block the wheels to prevent the vehicle from moving. If it is necessary to raise the vehicle to service the brake, use a jack to raise the vehicle. Support the vehicle with safety stands.
2.
Apply 1450 psi (100 bar) of hydraulic pressure to release the parking brake.
3.
Remove the screw cap.
4.
Loosen the lock nut. Use a male hex wrench, M8 for model 1270 brake or M10 for models 1286 and 1287 brakes, to turn the adjusting screw clockwise until both brake pads contact the brake disc.
5.
Turn the adjusting screw counterclockwise to set the TOTAL clearance specified in the following table.
Total Lining-to-Disc Clearance
Adjusting Screw Revolutions Models 1286 and 1287
Inch
mm
Model 1270
Minimum
0.020
0.5
1/4
1/5
Rated
0.040
1.0
1/2
2/5
Maximum
0.060
1.5
3/4
3/5
Maintenance Manual MM-4A Issued 04-03
Parking Brake Emergency Release WARNING When the parking brake is released, the vehicle does not have any park brake function. You must block the wheels to prevent the vehicle from moving. Serious personal injury and damage to components can result. If hydraulic pressure is not available, the parking brake can be manually released using the following procedure. 1.
Park the vehicle on a level surface. Block the wheels to prevent the vehicle from moving.
2.
Remove the screw cap.
3.
Loosen the lock nut.
4.
Use a male hex wrench, M8 for model 1270 brake or M10 for models 1286 and 1287 brakes, to turn the adjusting screw counterclockwise until the brake is released. Emergency release requires approximately 30 lb-ft (40 N•m) torque on the adjusting screw. T
5.
Tighten the lock nut. Install and hand-tighten the screw cap.
6.
Before you return the vehicle to service, adjust the brake using the procedure in this section.
Bleed Brake NOTE: When you loosen any brake system hydraulic connection, you must bleed the brake to remove all air from the system. 1.
Make sure that the master cylinder is filled to the specified level with the type of hydraulic fluid specified by the equipment manufacturer. Keep the master cylinder filled during bleeding so that you do not pull air into the system through the master cylinder. Make sure the master cylinder is filled when you are done bleeding the system.
2.
Put a clear tube on the bleeder screw. Submerge the other end of the tube in a clear container of the specified fluid.
Copyright 2003 AxleTech International
Page 7
Section 5 Adjustments 3.
Bleed brake. For full hydraulic systems: Slowly apply low hydraulic pressure to the brake. Loosen the bleeder screw. Continue to apply pressure until no air bubbles appear in the container of fluid. Tighten the bleeder screw 9-12 lb-ft (12-16 N•m), then release the pressure to the brake. T For air/hydraulic or mechanical actuator systems: Apply the brake pedal, then loosen the bleeder screw. Tighten the bleeder screw 9-12 lb-ft (12-16 N•m) before you release the brake pedal so that air is not pulled back into the system. Repeat this procedure until no air bubbles appear in the container of fluid when you apply the brake pedal. T
4.
Check for fluid leaks.
Page 8
Copyright 2003 AxleTech International
Maintenance Manual MM-4A Issued 04-03
Section 6 Specifications Section 6 Specifications
WARNING Use only the type of hydraulic fluid specified by the equipment manufacturer. Do not use or mix different types of hydraulic fluid. Using incorrect hydraulic fluid will damage the rubber parts of the caliper. Loss of braking control, serious personal injury and damage to components can result. Do not reuse hydraulic fluid. Used fluid can be contaminated and can cause incorrect operation. Serious personal injury and damage to components can result.
Hydraulic Fluid Petroleum base hydraulic fluid or mineral oil. Example: meets MIL-H-5606 specifications.
Hydraulic Pressure Release pressure is 1450 psi (100 bar). Never exceed 2,030 psi (140 bar). Fluid Volume Volume to release brake: Approximately 1.1 oz (33 cc), plus allowance for brake line. NOTE: Always verify brake is fully released when pressure is applied.
Seal Kit MPS4646
Part Name
Quantity
Exploded View Item Number
O-Ring
1
20
O-Ring
1
19
Cup Seal
1
13
Cup Seal
1
12
O-Ring
1
18
Dust Boot
1
8
Maintenance Manual MM-4A Issued 04-03
Copyright 2003 AxleTech International
Page 9
Suite 400 3001 West Big Beaver Road Troy, Michigan 48084 U.S.A. 877-877-9717 FAX: 248-435-1990 Website: www.axletech.com
AxleTech, International France 4, Rue Jean Servanton Boite Postale 656 42042 Saint Etienne Cedex 1 France (33) 477.92.88.00 FAX: (33) 477.92.88.93
MM-4A Issued 04-03
© Copyright AxleTech International Printed in the USA
