Disc & Drum Dodge Ram Wagon B3500

DESCRIPTION & OPERATION

All models are equipped with single piston, sliding caliper front disc brakes with ventilated cast rotors. Rear drum brakes use anti-lock cast brake drums. System also includes power brake booster, dual reservoir master cylinder and combination valve. Combination valve consists of metering valve and pressure differential switch.

On RWD vehicles, Rear Wheel Anti-Lock (RWAL) brakes are standard. All-Wheel Anti-Lock Brake System (ABS) which is also known as 4WAL brake system is available as an option.

Models without full floating rear axle use 9", 10" or 11" single anchor rear brakes. (Scheme 6) Models with 3/4 and one ton axle s use 11" or 12" single anchor rear drum brakes. (Scheme 7)or (Scheme 8).

Note. For information on Anti-Lock Brake Systems (ABS), see the ANTI-LOCK BRAKE SYSTEM - REAR WHEEL article or the ANTI-LOCK (4WAL) - KELSEY-HAYES EBC-5H article.

BLEEDING PROCEDURES

Before bleeding system, exhaust all vacuum from power unit by depressing brake pedal several times. Bleed master cylinder using bleeder screws (if equipped). Bleed slave cylinder on vehicles equipped with remote mount power assist units. Bleed wheel cylinders and calipers in sequence. See BLEEDING SEQUENCE table.

BLEEDING SEQUENCE

Master Cylinder (Bench Bleeding)

1. Bench bleed master cylinder before installation. Place master cylinder in soft-jawed vise. Install bleeder tubes in both outlets of master cylinder. (Scheme 1)
2. Fill master cylinder with clean brake fluid. Ensure ends of bleeder tubes are submerged in brake fluid.
3. Using a rod, apply and release master cylinder until no air bubbles exist in brake fluid flow. Leave bleeder tubes installed on master cylinder. Install master cylinder. Bleed brake system.

Scheme 1

Master Cylinder (On-Vehicle Bleeding)

1. Install master cylinder on vehicle. Remove bleeder tubes and install brake lines. DO NOT fully tighten brake lines at this time.
2. Slowly force brake pedal to floor, and hold pedal down. Tighten brake lines. Release brake pedal. Repeat procedure until no air bubbles exist at brake lines. Wheel cylinders and calipers may also require bleeding.

POSITIONING METERING VALVE BEFORE BLEEDING SYSTEM

1. Before using pressure tank bleeding procedure, correctly position metering valve (incorporated in combination valve) to allow brake fluid to flow through valve to entire brake system.
2. Valve stem may be retained in metering valve during bleeding procedure, using Valve Retainer (C-4121). (Scheme 2) Remove valve retainer once brake bleeding procedure is complete.

Scheme 2

VACUUM BLEEDING

Fill master cylinder. Install vacuum bleed equipment to first bleeder valve to be serviced. Open bleeder valve one turn. Depress vacuum pump, and pull fluid into reservoir jar. Bleed each bleeder valve in sequence. See BLEEDING PROCEDURES .

PRESSURE BLEEDING

1. Clean master cylinder cap and surrounding area. Remove cap. With pressure tank at least 1/2 full, connect it to master cylinder using appropriate adapters. Attach bleeder hose to first bleeder valve to be serviced. See «BLEEDING PROCEDURES»(/dodge/ram-wagon-b3500/1991-2000/remont/mechanical-hydraulic/#disc-drum__bleeding-procedures) .
2. Submerge other end of hose in clean glass jar partially filled with clean brake fluid. Position metering valve properly before pressure bleeding. See «POSITIONING METERING VALVE BEFORE BLEEDING»(/dodge/ram-wagon-b3500/1991-2000/remont/mechanical-hydraulic/#disc-drum__positioning-metering-valve-before-bleeding-system) SYSTEM.
3. Open release valve on pressure bleeder. Follow equipment manufacturer's pressure bleeding instructions. Open bleeder screw one turn, and note fluid flow.
4. Close bleeder screw when fluid flow is free of air bubbles. Repeat procedure on remaining wheels in proper sequence. Check brake pedal operation after bleeding.
5. Remove pressure bleeding equipment and valve retainer from metering valve (if installed). Ensure master cylinder is full of fluid.

MANUAL BLEEDING

Note. When bleeding disc brakes, air may tend to cling to caliper walls. Lightly tap caliper, while bleeding, to aid in removal of air.

Note. When bleeding brake system manually, ensure bleeder valve is closed when brake pedal is released.

1. Fill master cylinder. Install bleeder hose on first bleeder valve to be serviced. See «BLEEDING PROCEDURES»(/dodge/ram-wagon-b3500/1991-2000/remont/mechanical-hydraulic/#disc-drum__bleeding-procedures) . Submerge other end of hose in clean glass jar partially filled with clean brake fluid.
2. Open bleeder valve one turn. Depress brake pedal slowly through full travel. Close bleeder valve. Release pedal. Repeat procedure until fluid flow is free of air bubbles.

PARKING BRAKE

1. Release parking brake, and loosen cable adjusting nut to allow slack in cable. Adjust rear brakes. Tighten cable adjusting nut until a slight drag is felt while rotating rear wheels.
2. Loosen cable adjusting nut until both rear wheels can be rotated freely. Back off adjusting nut an additional 2 turns. Apply and release parking brake several times, checking for free rotation at rear wheels.

REAR BRAKE SHOES

1. Raise and support vehicle. Ensure parking brake is fully released. Remove rear wheels and brake drums. Ensure automatic adjuster levers and cables are properly connected. Insert brake gauge into brake drum. Expand brake gauge until inner legs of gauge contact inside of brake drum and lock into position.
2. Reverse brake gauge and install it onto center of brake shoes. Pull adjuster screw star wheel away from adjuster lever. Turn adjuster screw star wheel until brake gauge outside legs lightly drag on brake shoes. Repeat adjustment procedure on opposite brake shoes.
3. Install rear wheels and brake drums. Lower vehicle. Drive vehicle and make one complete forward stop followed by one complete reverse stop. Repeat this procedure 8-10 more times to operate automatic adjuster and equalize adjustment. If vehicle comes to a rolling stop instead of a complete stop, automatic adjusters will not be activated.

STOPLIGHT SWITCH

1. Remove either steering column trim cover or knee bolster to gain access to stoplight switch. Depress and hold brake pedal. Rotate stoplight switch counterclockwise about 1/16 turn to unlock switch. Pull switch straight out of mounting bracket and remove.
2. Pull switch plunger all the way out to fully extended position. Push switch plunger in 3 detents. Plunger will extend about .55" (14 mm) out of switch housing. Depress and hold brake pedal. Align switch locking collar index in switch bracket and install switch. Rotate stoplight switch clockwise about 1/16 turn to lock switch in place. Release brake pedal and gently pull pedal rearward against switch plunger. DO NOT use excessive force to pull brake pedal rearward or switch will be damaged. Pedal will adjust switch plunger to correct position. Install either steering column trim cover or knee bolster.

MASTER CYLINDER/POWER BOOSTER FUNCTIONAL TEST

1. Start engine, and check booster vacuum hose connections. A hissing noise indicates a vacuum leak. Repair any vacuum leaks before proceeding. Stop engine and shift transmission into Neutral. Pump brake pedal until all vacuum reserve in booster is depleted.
2. Hold brake pedal under light foot pressure. If pedal does not hold firm and falls away, master cylinder may be faulty. Bleed system using appropriate method, and repeat step 1). See the «BLEEDING PROCEDURES»(/dodge/ram-wagon-b3500/1991-2000/remont/mechanical-hydraulic/#disc-drum__bleeding-procedures) section.
3. If pedal still does not hold firm, master cylinder is faulty. If pedal holds firm, start engine and observe pedal action. If pedal action is not apparent, power booster or vacuum check valve is faulty. Install good check valve, and repeat steps 1) and 2). If pedal falls away slightly under light foot pressure and then holds firm, go to next step.
4. With engine running, rebuild booster vacuum reserve. Release brake pedal. Increase engine speed to 1500 RPM. Close throttle and immediately turn off ignition. Wait at least 90 seconds, and try brake action again. Booster should provide 2 or more vacuum assisted pedal applications. If vacuum assist is not provided, booster is faulty.

POWER BOOSTER VACUUM TEST

Connect vacuum gauge to booster check valve using "T" fitting. Start engine, and run it at idle speed for one minute. Clamp hose shut between vacuum source and check valve. Stop engine and observe vacuum gauge. If vacuum drops more than one in. Hg within 15 seconds, booster diaphragm or check valve is faulty.

POWER BRAKE BOOSTER CHECK VALVE TEST

Disconnect vacuum hose from check valve. Remove check valve and valve seal from booster. Using a hand operated vacuum pump, apply 15-20 in. Hg of vacuum at large end of check valve. Vacuum should hold steady. If gauge on pump indicates vacuum loss, check valve is faulty and should be replaced.

COMBINATION VALVE METERING VALVE TEST

Metering valve operation can be checked visually with aid of an assistant. While an assistant applies and releases brake pedal, observe metering valve stem. If valve is operating correctly, stem will extend slightly when brakes are applied and contract when brakes are released. If valve is faulty, replace combination valve assembly.

COMBINATION VALVE PRESSURE DIFFERENTIAL SWITCH TEST

1. Using an assistant, observe brake warning light and apply brake pedal. Raise and support vehicle. Connect a bleed hose to one rear wheel cylinder. Submerge other end of hose into container partially filled with brake fluid. Have assistant press and hold brake pedal down while observing brake warning light. If warning light glows, switch is operating properly.
2. If warning light fails to glow, check circuit fuse, bulb and wiring. Repair as necessary. Repeat step 1). If warning light fails to glow again, check brakelight, parking brake switches and related wiring. Repair as necessary. Repeat step 1). If warning light fails to glow again, pressure differential switch is faulty. Replace combination valve assembly, bleed brake system and verify proper valve operation.

CALIPER (BENDIX)

Removal

1. Raise and support vehicle. Remove wheels. Remove support key retaining screw. (Scheme 3) Using drift punch, drive out support key and spring. Remove caliper from adapter. Pry outer pad from caliper.
2. Support caliper aside. Remove inner pad and anti-rattle spring from adapter. Note position of anti-rattle spring on inner pad for installation. If reusing pads, mark pads for installation reference.

Scheme 3

Inspection

Replace pads if any part of lining is worn to within 1/8" (3 mm) of rivet heads or if bonded material is 3/16" (5 mm) or less. Inspect rotor. See inspection procedure for ROTOR under REMOVAL & INSTALLATION. Check piston seal for leaks and piston boot for cuts. If piston seal leaks or if boot is damaged, overhaul caliper assembly. Disconnect and plug hydraulic brake hose at caliper if caliper overhaul is necessary.

Installation

1. Clean caliper and adapter slide surfaces using wire brush. Lubricate with multipurpose grease. Install anti-rattle spring on inner pad, ensuring loop portion of spring is away from rotor. Install inner pad in adapter, ensuring spring remains in position.
2. Install outer pad in caliper. Free play should not exist between pad flange (tab) and caliper flange. If free play exists, bend pad flange (tab) until interference fit with caliper is obtained. If disc pad cannot be installed by hand, press into place using a block of wood and "C" clamp. Place caliper into position over rotor. Seat caliper in adapter.
3. Place support spring over support key. Install assembly between adapter and lower caliper machined surfaces. Tap assembly into place using drift punch. Install support key retaining screw, ensuring boss on screw fits into cut-out on support key.
4. If caliper overhaul was necessary, install brake hose. Bleed brake system. See appropriate bleeding procedure under «BLEEDING BRAKE SYSTEM»(/dodge/ram-wagon-b3500/1991-2000/remont/mechanical-hydraulic/#disc-drum) . Install wheels. Fill reservoir to proper level. Slowly pump brake pedal until firm. Check reservoir fluid level. Road test vehicle.

Raise and support vehicle. Remove wheels. Remove caliper retainer bolts, anti-rattle springs and clips. (Scheme 4) Carefully lift caliper assembly away from rotor. Pry between outer pad and caliper to remove outer pad. Support caliper aside. Remove inner pad from adapter.

Scheme 4

1. Clean caliper and adapter slide surfaces. Install inner pad into adapter. Lubricate slide surfaces of adapter and caliper with multipurpose grease. Remove protective paper from noise suppression gasket on outer pad. Install outer pad in caliper. Free play should not exist between pad flange (tab) and caliper flange. If free play exists, bend pad flange (tab) until interference fit with caliper is obtained.
2. Install caliper over rotor. Align caliper in adapter. Install retainer clips and anti-rattle springs. Install brake hose if caliper overhaul was necessary. Bleed brake system. See appropriate bleeding procedures under «BLEEDING BRAKE SYSTEM»(/dodge/ram-wagon-b3500/1991-2000/remont/mechanical-hydraulic/#disc-drum) . Install wheels. Fill master cylinder to proper level. Slowly pump brake pedal to obtain firm pedal. Check master cylinder fluid level. Road test vehicle.

Raise and support vehicle. Remove front wheels. Remove caliper guide pins. Pry caliper away from adapter and pads. (Scheme 5) Remove caliper. Support caliper aside. Remove outer pad, rotor and inner pad.

Scheme 5

1. Clean caliper and adapter slide surfaces using wire brush. Lubricate caliper and adapter slide surfaces with multipurpose grease. Remove protective paper from noise suppression gasket on inner and outer pads. Install anti-rattle clip on top of adapter. Install inner pad, rotor and outer pad. Install caliper assembly. Install and tighten caliper guide pins.
2. If caliper overhaul was necessary, install brake hose. Bleed brake system. See «BLEEDING BRAKE SYSTEM»(/dodge/ram-wagon-b3500/1991-2000/remont/mechanical-hydraulic/#disc-drum) . Install wheels. Fill master cylinder to proper level. Slowly pump brake pedal until firm. Check master cylinder fluid level. Road test vehicle.

ROTOR

1. Raise and support vehicle. Remove wheels. Remove dust cap and temporarily adjust wheel bearings to zero end play.
2. Mount dial indicator on steering arm, with plunger contacting rotor about 1" (25 mm) from edge of rotor. Slowly rotate rotor and note lateral runout. Lateral runout on either side of rotor should not exceed specification. maximum allowable runout is .004" (.10 mm).
3. If hub runout is within specification, install rotor on hub with chalk marks 180 degrees apart. Install wheel lug nuts and recheck rotor runout. If runout is not within specification, resurface or replace rotor.
4. Measure rotor parallelism. To measure parallelism, measure rotor thickness with micrometer at 12 equal points around rotor radius approximately 1" (25 mm) from edge of rotor. If thickness varies more than parallelism specification, resurface or replace rotor. See «DISC BRAKE SPECIFICATIONS»(/dodge/ram-wagon-b3500/1991-2000/remont/mechanical-hydraulic/#disc-drum__disc-brake-specifications) .

Raise and support vehicle. Remove wheels. Bottom caliper piston in bore. Remove brake caliper from adapter. Support caliper aside. Remove grease cap, cotter pin, nut lock, nut, thrust washer and outer wheel bearing. Pull rotor assembly off spindle.

1. Slide rotor assembly into position on spindle. Pack and install outer wheel bearing, thrust washer and nut. While rotating rotor and hub assembly, tighten wheel bearing nut to 20-25 ft. lbs.(27-34 N.m).
2. Back off nut to release preload. Retighten nut finger tight. Install nut lock and cotter pin. Coat inside of cap with grease, and install cap. To complete installation, reverse removal procedure.

Removal (9", 10" & 11" Drums)

1. Remove wheel and drum. Note how secondary spring overlaps primary spring. Using spring remover, remove brake shoe return springs. Slide automatic adjuster cable off anchor. Disconnect cable from adjusting lever.
2. Remove cable, cable guide and anchor plate. (Scheme 6) Disconnect adjusting lever return spring from lever. Remove lever and return spring from pivot pin. Remove shoe-to-shoe spring. Spread shoes and remove adjustment star wheel.
3. Remove shoe retainers, springs and nails. Remove parking brake lever from secondary shoe. Remove shoes and parking brake strut with spring.

Scheme 6

1. Apply a thin coat of multipurpose grease to 6 shoe contact pads on support plate. Connect parking brake lever to secondary shoe. Install primary shoe on support plate with shoe nail, spring and retainer.
2. Install spring on parking brake strut and engage strut into primary shoe. Install secondary shoe on support plate with shoe nail, spring and retainer. Insert strut into slot in parking brake lever.
3. Install anchor plate and eye of adjusting cable over anchor. Install primary return spring. Position cable guide over hole in secondary shoe and install secondary return spring. NOTE: To identify left and right adjustment star wheels, unscrew threaded rod from star wheel. Note stamped "L" or "R" on end of threaded rod.
4. Install adjustment star wheel with wheel closest to secondary shoe. Install shoe-to-shoe spring, engaging in primary shoe first with coil on opposite side of adjusting lever. Install lever spring and adjusting lever over pivot pin.
5. Slide lever rearward to lock in position. Thread adjuster cable over guide and hook end of cable in lever. Verify adjuster operation. Pull adjuster cable upward. Cable should lift lever and rotate star wheel. Ensure adjuster lever properly engages star wheel teeth. Adjust brakes. See «REAR BRAKE SHOES»(/dodge/ram-wagon-b3500/1991-2000/remont/mechanical-hydraulic/#disc-drum) under ADJUSTMENTS.

Removal (12" Drum)

1. Remove wheel and drum. See «AXLE BEARING & SEAL»(/dodge/ram-wagon-b3500/1991-2000/remont/mechanical-hydraulic/#disc-drum) (FULL FLOATING AXLE). Disconnect adjusting lever from cable. Disconnect adjusting lever return spring from lever. Remove lever and return spring from pivot pin. Remove upper shoe-to-shoe spring.
2. Disconnect and remove shoe retainers, springs and hold-down pins. Disconnect parking brake cable from lever. Remove both brake shoes, lower shoe-to-shoe spring and adjustment star wheel as an assembly. (Scheme 7) Remove lower shoe-to-shoe spring.

Note. Adjustment star wheel on left brake assembly has left-hand threads. Right side assembly has right-hand threads.

1. Lubricate and assemble adjustment star wheel. Apply a thin film of multipurpose grease to shoe contact pads on support plate. Assemble lower shoe-to-shoe spring, adjustment star wheel and both shoes. Position shoe assembly on support plate.
2. Attach parking brake cable to lever. Install shoe hold-down pins, springs and retainers. Install upper shoe-to-shoe spring. Position adjusting lever return spring on pivot. Install adjusting lever. Route cable, and connect it to adjuster. Install drum assembly and wheel. Adjust brakes. See «REAR BRAKE SHOES»(/dodge/ram-wagon-b3500/1991-2000/remont/mechanical-hydraulic/#disc-drum) under ADJUSTMENTS.

Scheme 7

Removal & Installation

1. Remove wheel, drum and brake shoes. Inspect boots for damage and signs of leakage. Disconnect and plug hydraulic brake line from wheel cylinder. Remove attaching bolts, and remove cylinder. (Scheme 8)
2. Apply silicone sealant to cylinder mounting surface, and position cylinder on support plate. Start brake line fitting in wheel cylinder. Install and tighten mounting bolts. Tighten brake line fitting. To complete installation, reverse removal procedure. Fill brake fluid reservoir, and bleed hydraulic system. See «BLEEDING PROCEDURES»(/dodge/ram-wagon-b3500/1991-2000/remont/mechanical-hydraulic/#disc-drum__bleeding-procedures) under BLEEDING BRAKE SYSTEM.

Scheme 8

1. Disconnect and plug primary and secondary brake lines from master cylinder. Remove master cylinder-to-power brake booster nuts. Slide master cylinder straight out and away from power brake booster unit. (Scheme 9)
2. To install, position master cylinder over studs of power brake booster. Align power cylinder brake push rod with cylinder piston. Install master cylinder nuts, and tighten to specification. See «TORQUE SPECIFICATIONS»(/dodge/ram-wagon-b3500/1991-2000/remont/mechanical-hydraulic/#disc-drum__torque-specifications). Connect brake lines. Bleed system. See «BLEEDING BRAKE SYSTEM»(/dodge/ram-wagon-b3500/1991-2000/remont/mechanical-hydraulic/#disc-drum).

Scheme 9

Removal (In-Line Mount)

1. Disconnect vacuum hose from booster check valve. Remove nuts attaching master cylinder and move cylinder away from booster. Inside vehicle, remove booster push rod-to-brake pedal clip. Pry clip off pedal pivot pin.
2. Remove lock nuts from booster mounting studs. Slide booster away from dash and out of engine compartment. If booster is being replaced, remove booster check valve and seal.

1. If new booster is being installed, install check valve and seal. Position booster on dash and install lock nuts on booster mounting studs finger tight. Install booster push rod on brake pedal pin and secure rod with new retaining clip.
2. Tighten booster lock nuts to 18 ft. lbs. (24 N.m). Install master cylinder on booster, and tighten mounting nuts to 16 ft. lbs. (22 N.m). Connect vacuum hose to booster check valve. Start vehicle and check booster operation.

Removal (Transverse Mount)

Disconnect vacuum hose from booster check valve. Remove nuts attaching master cylinder to booster studs. Remove master cylinder from booster. Remove pivot bolt, "O" ring and nut attaching booster rod to bellcrank. Remove lock nuts attaching booster to mounting bracket. Slide booster off mounting bracket and out of engine compartment. If booster is being replaced, remove booster check valve and seal.

1. Install check valve and seal if new booster is being installed. Position booster on mounting bracket and install lock nuts on booster mounting studs finger tight. Align booster rod with bellcrank arm, and install pivot pin, "O" ring and nut.
2. Tighten booster lock nuts and pivot pin nut to 30 ft. lbs. (41 N.m). Install master cylinder on booster. Tighten mounting nuts to 16 ft. lbs. (22 N.m). Connect vacuum hose to booster check valve. Start vehicle and check booster operation.

Raise and support vehicle. Mark brake lines for assembly reference. Disconnect parking brake cable from clip on valve. Disconnect brake warning light connection at switch. Disconnect all brake hydraulic lines at valve. Cap brake lines to prevent dirt from entering system. Remove valve. To install, reverse removal procedure. Bleed brake system. See BLEEDING PROCEDURES under BLEEDING BRAKE SYSTEM.

Removal & Installation (12" Drum)

1. Raise and support vehicle. Remove wheel. Remove axle shaft nuts and washers. Strike center of axle flange to free cones. Remove axle shaft and gasket.
2. Straighten and remove nut lock. Remove adjustment nut and outer bearing. Remove drum assembly. Remove seal and inner bearing from drum assembly.
3. Pack and install inner bearing and seal in drum. Install drum assembly, outer bearing and adjustment nut. While rotating drum, tighten adjustment nut to 120-140 ft. lbs. (163-190 N.m).
4. Back off adjustment nut 1/3 turn (120 degrees) to obtain .001-.008" (0.03-0.20 mm) end play. Bend nut lock into spindle keyway. Install gasket and axle shaft. Install wheel, and lower vehicle. See «TORQUE SPECIFICATIONS»(/dodge/ram-wagon-b3500/1991-2000/remont/mechanical-hydraulic/#disc-drum__torque-specifications) table.

OVERHAUL

Note. When overhauling components (Scheme 3)- (Scheme 9).

Note. Only the nylon reservoir and grommets are serviceable. Master cylinder body is only serviced as an assembly.

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

DISC BRAKE SPECIFICATIONS

DISC BRAKE SPECIFICATIONS

DRUM BRAKE SPECIFICATIONS

DRUM BRAKE SPECIFICATIONS

See also:
• ANTI-LOCK BRAKE SYSTEM - REAR WHEEL
• ANTI-LOCK (4WAL) - KELSEY-HAYES EBC-5H
• BLEEDING SEQUENCE
• BLEEDING PROCEDURES
• POSITIONING METERING VALVE BEFORE BLEEDING SYSTEM
• ROTOR
• DISC BRAKE SPECIFICATIONS
• TORQUE SPECIFICATIONS