Disc & Drum Dodge Ram I

BRAKE SYSTEM

Brake system consists of a master cylinder, vacuum power brake unit and proportioning valve. Colt Vista 2WD models and Ram-50 models have a height sensing proportioning valve. All brake systems are self-adjusting. All models are equipped with front disc brakes. All models are equipped with rear drum brakes. Parking brake is connected to rear brakes.

PEDAL HEIGHT & FREE PLAY

Back off stoplight switch. To adjust pedal height (distance from top of pedal to floor board) loosen lock nut, and rotate master cylinder push rod (yoke, if equipped). DO NOT depress push rod. Tighten lock nut, and ensure that brake pedal free play is .40-.60" (10-15 mm) on all other models.

FRONT DISC BRAKE PADS

Removal (Raider)

1. Raise and support vehicle. Remove front wheel. Remove spigot pins and pull out stopper plugs.
2. Pull caliper assembly up and down in a diagonal manner, and remove from mounting bracket. Remove inner and outer pad clips. Pull pads and anti-squeal shims from caliper support.

Installation

To install, reverse removal procedure. Press piston to bottom of caliper bore prior to pad installation. Make sure pad retaining clips are installed properly. (Scheme 1)

Installing Raider Pad Retaining Clips. Scheme 1

Removal (All Others)

1. Raise and support vehicle. Remove front wheel. Remove lock pin or bottom sleeve bolt. Lift caliper body upward.
2. Support caliper on a wire. Remove inner shim(s), anti- squeak shim, and pad assembly from support mounting. Remove pad clips.

Note. Replace all pads (left and right side) at the same time.

Press piston to bottom of bore. Install retaining clips, pad assembly, inner shim(s) and anti-squeak shim onto support mounting. (Scheme 2)and (Scheme 3). Lower caliper body and install lock pin.

Exploded View of Front Disc Brake Assembly (Colt W/1.5L). Scheme 2

Exploded View of Front Disc Brake Assembly (All Other). Scheme 3

Remove disc pads. Pull out hose clip from strut area. Disconnect brake hose from caliper. Remove caliper.

To install, reverse removal procedure. Tighten bolts to specification and bleed brake system.

Removal (All Except Raider)

Remove disc pads. Disconnect hydraulic line, and remove bolts attaching caliper assembly to steering knuckle. Remove caliper assembly.

To install, reverse removal procedure. Tighten caliper mounting bolts to specification and bleed hydraulic system.

FRONT DISC BRAKE ROTOR

Removal (Colt, Colt Vista)

1. Raise and support front of vehicle. Remove front wheels. Remove caliper. On all models, remove cotter pin, wheel bearing nut and washer. Remove lower ball joint nut. Position Puller (MB991113) to separate lower ball joint from steering knuckle.
2. Secure puller cord. DO NOT remove nut from puller. Using puller separate tie rod from steering knuckle. Disconnect stabilizer bar from lower arm. Using 2 screwdrivers, 11.4" (290 mm) in length, remove drive shaft from transaxle or center bearing. (Scheme 4) DO NOT use a pry bar.
3. Disconnect strut assembly from knuckle. Remove hub and knuckle assembly. Using Bracket (MB991056) and Bolt (MB990998), separate knuckle from hub. Remove rotor from hub.

1. Using Bolt (MB990998), install hub and rotor assembly into knuckle. On Colt Vista, tighten bolt to 144-188 ft. lbs. (196-256 N.m). Rotate hub to seat bearings. Measure hub starting torque and wheel bearing end play.
2. Starting torque should be 11 INCH lbs. (1.3 N.m) on 2WD models, or 16 INCH lbs. (1.8 N.m) on 4WD models, or greater. End play should be .008" (.20 mm) or more. If not, check for correct installation of hub. On all models, reverse removal procedure to complete installation.

Removing Drive Shaft From Transaxle. Scheme 4

Removal (Raider & 4WD Ram-50 Pickup)

With caliper assembly removed and supported by a wire, remove front hub assembly from the knuckle. See LOCKING HUBS article. After marking the hub and disc, disassemble the hub from the disc.

Note. If removal or replacement of bearings or races is necessary, see appropriate articles in FRONT SUSPENSION section.

To install, reverse removal procedures and tighten to specifications. See appropriate articles in SUSPENSION section.

Removal (2WD Ram-50 Pickup)

Remove front caliper. Remove hub cap, cotter pin and nut. Remove washer and outer wheel bearing. Remove front hub assembly. Remove bolts attaching rotor to front hub.

To install, reverse removal procedure. Tighten wheel bearings in the following sequence: 22 ft. lbs. (30 N.m), loosen, then tighten to 72 INCH lbs. (8 N.m). To install cotter pin, loosen nut 30 degrees maximum.

Removal (Colt Vista)

1. Raise and support vehicle. Remove brake drum and hold-down springs. (Scheme 5) Disconnect strut-to-shoe spring and upper shoe return spring end from trailing shoe.
2. Remove shoe hold-down spring and shoe retaining spring. Remove leading shoe. Remove parking brake cable from parking brake lever. Remove trailing shoe.

Colt Vista Rear Brakes. Scheme 5

Removal (Raider & Ram-50 Pickup)

1. Raise and support vehicle. Remove brake drum. Remove shoe return spring, shoe retainer spring and shoe hold-down pin. (Scheme 6)
2. Remove shoe and lining assembly and shoe and lever assembly. Remove cable from parking lever. Remove brake tube from wheel cylinder and wheel cylinder from backing plate.
3. Remove backing plate together with axle shaft. DO NOT remove backing plate from axle shaft, unless absolutely necessary.

Removal (Colt)

1. Raise and support vehicle. Remove brake drum, clip spring, shoe retainer spring, shoe-to-shoe spring and hold-down spring. (Scheme 7)
2. Remove shoes and adjuster as an assembly and separate. Remove parking brake cable from lever.

Installation (All Models)

1. To install, reverse removal procedure. Apply Lubriplate to all shoe contact points, adjuster assembly, wheel cylinder and parking brake lever pin.
2. Set adjustment lever all the way back. After assembling the brake shoes, install brake drum. Depress brake pedal to adjust shoe clearance. Adjust parking brake.
3. Ensure adjuster lever meshes with next tooth of adjuster when pulled, and returns to original position after wheel has moved one tooth. Adjuster assemblies differ between right and left sides.

Exploded View of Raider & Ram-50 Pickup Rear Brake Assembly. Scheme 6

Colt Rear Brake Assembly. Scheme 7

1. With drum removed, disconnect brake line from wheel cylinder. Disconnect bearing case from axle housing end. Remove brake backing plate, bearing case, and axle shaft as an assembly. If axle shaft binds, use Slide Hammer (CT-1003) and Puller (CT-637).
2. Remove "O" ring and shims for preloading wheel bearing. Retain shims for reassembly. Using slide hammer and hook on Ram-50 Pickup and screwdriver on Raider, remove oil seal.
3. To remove wheel bearing, remove lock washer and lock nut, using Remover (MB990785). Remove lock washer and washer. Reinsert lock nut on axle shaft approximately 3 turns. Install Puller (MB990787-A) to remove bearing case from axle shaft.
4. Turn nuts with equal pressure to ensure smooth removal of wheel bearing. Using a hammer and drift, drive bearing outer race from bearing case. Remove oil seal from bearing case.

1. Apply Multipurpose Grease (2525035) to oil seal. Install oil seal using Installer (C-4572). Apply grease to outside circum- ference of bearing outer race. Press race into bearing case.
2. Apply grease to lip of oil seal and to roller surfaces of bearing inner race. Install rear brake assembly and bearing case. Press inner bearing race onto the axle shaft.
3. Pack bearing case and axle threads with grease. Install lock washer (tab aligned with axle slot) and lock nut (chamfer toward lock washer). Tighten nut to 130-159 ft. lbs. (176-216 N.m). Bend tabs on lock washer into slots of lock nut.
4. Apply grease to oil seal area of rear axle housing. Install new oil seal into end of rear axle housing. Adjust clearance between bearing case and rear axle by inserting.04" (1.0 mm) shim and "O" ring into left rear axle housing.
5. Apply semi-drying sealant to mating surface of bearing case. Install left axle shaft into rear housing and tighten nuts diagonally to 36-43 ft. lbs. (50-58 N.m).
6. Install right axle shaft without shims and "O" ring. Temporarily tighten to about 53 INCH lbs. (6 N.m). Using a feeler gauge, measure clearance between bearing case and rear axle housing.
7. Remove right axle shaft. Install shims to equal measure- ment plus.002-.008" (.05-.20 mm). Install "O" ring to right rear axle housing. Apply sealant to mating surface of bearing case. (Scheme 8) Install axle into housing, tightening nuts diagonally to 36-43 ft. lbs. (50-58 N.m).
8. Using dial indicator, check axle shaft for.002-.008" (.05-.20 mm) end play.

Applying Sealer for "O" Ring & Shim. Scheme 8

Removal (Colt Vista 4WD)

Remove brake drum. Remove companion flange bolts. Using Wrench (MB990767), remove companion flange nut. Remove companion flange. Using a slide hammer, remove axle shaft. Press bearing from axle shaft. Remove backing plate. Mark inner arm position. Remove inner arm bolts. Remove oil seal and bearing from inner arm.

1. Using Driver (MB9900938) and Adapter (MB990931), install bearing in inner arm. Using Driver (MB990799), install oil seal with concave surface facing outward, from rear of inner arm. Align marks and install inner arm bolts.
2. Apply semi-drying sealant to inner arm mating surface. Install backing plate. Install dust cover onto axle shaft, with concave side facing bearing. Press bearing onto axle shaft.
3. Install companion flange and nut. Tighten nut to 116-159 ft. lbs. (158-216 N.m). Ensure end play is .031" (.79 mm). If not, check wheel bearings. Reconnect companion flange to drive axle. Install brake drum.

Removal (FWD Models)

With brake drum removed, pry out oil seal with screwdriver. Remove bearing outer races using a hammer and soft punch.

Installation (Colt)

Install bearing retaining nut until it is.08-.12" (2-3 mm) from stop. (Scheme 9) Check turning torque when LOOSENING from this point. Turning torque should be 48 ft. lbs. (65 N.m). If not, replace nut. To install, reverse removal procedure. Tighten rear wheel bearing nut to 72-108 ft. lbs. (98-147 N.m).

Installation (Colt Vista 2WD)

To install, reverse removal procedure. Adjust rear wheel bearings in the following order: Tighten nut to 14 ft. lbs. (19 N.m). Loosen nut, then tighten to 84 INCH lbs. (10 N.m). To install cotter pin, loosen nut 15 degrees maximum.

Installing Bearing Retaining Nut (Colt). Scheme 9

Colt

1. Raise and support vehicle. Remove wheel. Release parking brake. Measure brake drum end play with dial indicator. Maximum end play is .008" (.20 mm).
2. If end play exceeds limit, retighten wheel bearing nut to 72-108 ft. lbs. (100-150 N.m). Recheck end play. Replace wheel bearings if end play exceeds specification.

INSPECTION OF REAR WHEEL BEARING NUT

1. Set the rear wheel bearing nut at the position shown. see scheme 10
2. Turn nut counterclockwise and measure the turning torque required. Measure the torque indicated between the start of turning and 2 to 3 turns. NOTE: The limit for the torque is 48 ft.lbs. (67.2 N.m). Be sure to measure the turning torque when loosening the nut.
3. If the measured torque does not reach the limit, replace the rear wheel bearing nut with a new one.

Removal

Remove the sensor connector (if equipped). Disconnect brake lines from master cylinder. Slowly depress brake pedal several times to drain fluid from cylinder housing. Remove master cylinder from booster unit and separate reservoirs from housing.

PUSH ROD CLEARANCE SPECIFICATIONS

Reverse removal procedure. Prior to installation, check and adjust clearance between back of master cylinder piston and power brake push rod. See PUSH ROD CLEARANCE SPECIFICATIONS table. After installation, adjust pedal height and bleed brake system.

POWER BRAKE UNIT CHECK VALVE REPLACEMENT

Note. Test check valve before removal. Pull off vacuum hose on booster side of check valve. Place finger over check valve, and crank engine. Vacuum should be felt.

Remove hose clamps from both ends of check valve. Remove check valve clamp and remove check valve.

Coat both ends of check valve with sealer and install valve with arrow (identification mark) pointing toward intake manifold side. Install check valve clamp and vacuum hoses, and secure hose clamps.

Remove the brake master cylinder, and disconnect vacuum hose from power brake unit. Disconnect brake pedal and operating rod of power brake unit. From inside vehicle, remove 4 nuts attaching power brake unit to firewall. Remove power brake unit.

To install, reverse removal procedure. Install master cylinder. Bleed brake system, if necessary.

Disassembly

Remove dust boot. Apply compressed air to fluid inlet to remove piston. Remove piston seal without damaging caliper bore or seal groove.

Note. Repair kits contain proper lubricants to be used during reassembly.

Reassembly

Coat piston seal with rubber grease. Slide seal into groove in cylinder bore. Slip piston into bore making sure seal is not twisted. Lightly coat dust seal groove with recommended rubber grease. Fit dust boot into place. Refit cylinder to caliper.

Note. Possible cause of increased pedal stroke is insufficient fit between piston and piston seal. Correct by manually levering piston to seat several times. This will create a better fit between piston and seal. Ensure brake pad is removed during this procedure.

Exploded View of Front Disc Brake Caliper (Raider). Scheme 10

While holding cylinder in a soft-jawed vise, remove dust boot, retaining ring, stop washer and piston stop bolt. Withdraw primary piston assembly, secondary piston assembly and secondary return spring from master cylinder. Remove check valve caps, tube seats, check valves and check valve springs. (Scheme 11)

Note. DO NOT disassemble primary and secondary piston assembly.

Cleaning & Inspection

Check master cylinder bore and piston for wear or other damage. Replace as necessary. Check clearance between cylinder bore and piston. If clearance exceeds .006" (.15 mm), replace master cylinder assembly.

Reverse disassembly procedure. Before reassembly, apply rubber grease to all parts (except boots). When assembled, check that return port is not blocked by piston cup, when piston is at return position.

Disassembled View of Master Cylinder. Scheme 11

TORQUE SPECIFICATIONS (COLT)

COLT VISTA

TORQUE SPECIFICATIONS (COLT VISTA)

RAIDER & RAM-50 PICKUP

TORQUE SPECIFICATIONS (RAIDER & RAM-50 PICKUP)

DISC BRAKE ROTOR SPECIFICATIONS (COLT)

DISC BRAKE ROTOR SPECIFICATIONS (COLT VISTA)

RAIDER

DISC BRAKE ROTOR SPECIFICATIONS (RAIDER)

RAM-50 PICKUP

DISC BRAKE ROTOR SPECIFICATIONS (RAM-50 PICKUP)

DRUM BRAKE SPECIFICATIONS (COLT)

DRUM BRAKE SPECIFICATIONS (COLT VISTA)

DRUM BRAKE SPECIFICATIONS (RAIDER)

DRUM BRAKE SPECIFICATIONS (RAM-50 PICKUP)

PEDAL HEIGHT SPECIFICATIONS

PEDAL HEIGHT SPECIFICATIONS

After adjustment is made, start engine. Check pedal height. If clearance is not at least 3.7" (95 mm) on Raider, bleed system and check for misadjusted brakes.

STOPLIGHT SWITCH

On all models, loosen lock nut and adjust switch-to-pedal arm clearance to .02-.04"(.5-1.0 mm). Tighten lock nut. DO NOT depress master cylinder push rod during stoplight switch adjustment.

PARKING BRAKE

Note. If parking brake lever stroke is not to specifications after adjustment, automatic adjuster will malfunction.

Colt & Colt Vista

Remove console box or parking brake lever cover. Adjust the cable adjusting nut, allowing enough slack in cables to prevent brake shoe drag. Properly adjusted parking brake lever stroke should be 5-7 notches at 44 lbs. (20 kg) force.

When parking brake lever is pulled with a force of 45 lbs. (20.4 kg), the lever stroke should be 4-6 notches. If not, remove accessory box or parking brake lever cover. Turn cable adjusting nut until specified number of notches are obtained with a pull of 45 lbs. (20.4 kg) force.

1. Service brake adjustment must be accurate before making parking brake adjustment. Fully release parking brake, and allow slack in rear cable to prevent brake shoe drag.
2. Adjust turnbuckle for 2WD models (turn adjusting nut on equalizer for 4WD models) to obtain a brake lever stroke of 16-17 notches with a 66 lbs. (29.9 kg) setting force.
3. On 2WD models, balancer must be parallel with center line of vehicle. On 4WD models, the equalizer and joint must be at right angles to each other.

HEIGHT SENSING PROPORTIONING VALVE

Note. Remove all luggage and passengers before checking and adjusting. Ensure vehicle is parked on level surface.

Ensure lever is not against stopper bolt. Check spring length. If not 3.42-3.50" (86.9-88.9 mm), adjust cable until proper length is obtained. (Scheme 12)

Ensure lever is not against stopper bolt. Check spring length. If not 6.85-6.93" (174.0-176.0 mm), adjust support until proper length is obtained.

Measuring Height Sensing Proportioning Valve Spring (Colt Vista). Scheme 12

See also:
• PUSH ROD CLEARANCE SPECIFICATIONS