Thursday, July 11, 2013

Dodge Colt 1971-43 Brake Repair Guide

Dodge Colt uses two different braking systems on 1973 models. Early models (manufactured through December, 1972) use dual piston fixed caliper disc brakes on front wheels, and manually adjusted leading-trailing shoe/drum brakes on rear wheels. Late models (manufactured since January, 1973) use single piston floating caliper disc brakes on front wheels, and self-adjusting leading-trailing shoe/drum brakes on rear wheels. Models equipped with the later model braking system with the following identification numbers.
6H23K35 117753 6L21K35 307874
6H23K39 124991 6L21K39 300111
6H41K35 108843 6P23K35 000643
6H41K39 114906 6P23K39 000457
6H45K35 109389 6P45K35 000411
6H45K39 116220 6P45K39 000521
All models are equipped with tandem master cylinder, consisting of independent front and rear hydraulic systems; a pressure differential warning switch, actuating on indicator lamp on instrument panel in the event of a pressure drop in front or rear hydraulic system; and a cable actuated parking brake assembly, acting on rear wheels.

Front disc brakes are self-adjusting, therefore, no adjustment in service is required.
Early Models - Release parking brake. Using a suitable brake adjusting tool (CT-1107), tighten adjuster clockwise until brake shoes just contact drum. Back off adjuster until drum rotates freely. When propery adjusted, brake shoe-to-drum clearance should be .004-.012"
Late Models - Rear drum brakes are self-adjusting, therefore, no adjustment in service is required.
All Models - 1) Release parking brake lever. Loosen cable lever attaching bolt and adjusting nut, and move cable lever to right. Adjust clearance to left cable to .04", then tighten attaching bolt. Clearance is measured between extension lever and backing plate on early models, or between extension lever and stopper on late models.
2) With let cable adjusted, turn adjusting nut until some clearance is obtained at right extension lever. With parking brake properly adjusted, parking brake lever stroke should be less than 7 notches (14 clicks) on early models, or 4-6 notches (8-12 clicks) on late models.
Attach a bleed tube to wheel cylinder bleeder screw and immerse opposite end of tube in container partially filled with brake fluid. Depress and release pedal several times, hold in applied position, loosen bleeder screw, allow air to escape and tighten bleeder screw. Continue operation until air bubbles are no longer seen in discharged fluid. Repeat procedure at remaining brake lines until all air is bled from system. Bleeding sequence is right-rear, left-rear, left-front, and right-front.

Removal (Early Models) - Raise and support vehicle and remove front wheel. Remove clips holding pad retaining pins in place, then remove pins and cross spring. Using pliers, pull disc pads from caliper assembly.
Installation - Press pistons to bottoms of bores using a suitable tool, and install disc pads and shims. NOTE - Make sure shims are installed between pad and piston, and arrow mark on shim faces forward. Insert upper pin into caliper with "A" portion of cross spring hooked on retaining pin, then install clip. Insert lower retaining pin and install clip, making sure pad shim is between cross spring flanges ("B"). Firmly press "C" portion of spring onto retaining pin. See Illustration.
Removal (Late Models) - Raise and support vehicle and remove front wheel. Remove pad protector by prying up edge of clip at center of protector with a screwdriver. Hold center of "M" clip, detach "M" clip

from pad and its ends from retaining pins from caliper and remove "K" spring. Remove pads from caliper by grasping backing plate area of pads with pliers.
Installation - Press piston to bottom of bore using a suitable tool, install disc pads and retaining pins. Install "K" spring and "M" clip, making sure positions are not reversed.
See illustration. Install pad protector, making sure clips face outward.
Removal (All) - With disc pads removed, disconnect hydraulic line and remove bolts attaching caliper assembly to steering knuckle, and remove caliper assembly.
Installation - Reverse removal procedure, tighten caliper mounting bolts evenly, and bleed hydraulic system.

Removal (All) - With caliper assembly removed, remove hub dust cap, cotter pin, lock nut, and adjustment nut. Pull hub and rotor assembly from spindle, taking care not to drop outer wheel bearing. Remove bolts attaching rotor to hub, then separate.
Installation - Reverse removal procedure, tighten rotor-to-hub bolts evenly, and adjust wheel bearings. 
Removal (Early Models) - Raise and support vehicle and remove brake drum. Remove shoe hold-down springs and shoe return spring. Pull upper shoe ends from wheel cylinder and remove brake shoe assembly.
Installation - Reverse removal procedure and note the following: Apply brake grease to all shoe contact points of backing plate, adjuster assembly, and wheel cylinder. Brake shoes are not interchangeable. See illustration for proper installation.

Removal (Late Models) - Raise and support vehicle and remove brake drum. Remove shoe hold-down springs. Disconnect strut-to-shoe spring and upper shoe return spring end from trailing shoe. Remove trailing shoe and lower return spring. Hold adjusting latch downward, pull adjusting lever toward center of brake, and remove leading shoe assembly. Remove upper shoe return spring and strut-to-shoe spring.
Installation - Reverse removal procedure and note the following: Apply brake grease to all shoe contact points of backing plate, adjuster assembly, and wheel cylinder. Adjust amount of engagement of adjusting lever with strut only after pulling lever fully toward center of brake. Note the adjusting lever and latch spring differ between right and left sides.
Removal (All) - With rear drum and brake shoes removed, disconnect hydraulic line from wheel cylinder at rear of backing plate, remove volts attaching cylinder, and remove wheel cylinder.
Installation - Reverse removal procedure, tighten mounting bolts evenly, and bleed hydraulic system.
Removal - Disconnect hydraulic lines from master cylinder, then depress pedal slowly several times to discharge fluid. Remove clevis bolt retaining master cylinder push rod to pedal, remove cylinder mounting bolts, and remove master cylinder.
Installation - Reverse removal procedure, check and adjust pedal height, and bleed hydraulic system.

Disassembly (Early Models) -Remove retaining rings and dust seals. Remove outer piston from caliper by holding inner piston with a screw driver, and applying compressed air to fluid inlet. Remove inner piston by inserting a driver in fluid inlet and tapping out. Remove piston seals, taking care not to damage caliper bores or seal grooves.NOTE - Do not separate caliper halves or loosen bridge bolts.
Cleaning & Inspection - Clean all parts in brake fluid and inspect for wear or damage; replace all worn, damaged or rusty cylinders and pistons. NOTE - Manufacturer recommends replacing piston seals and dust seals whenever caliper has been disassembled.
Reassembly - Apply rubber grease to piston seals and install into caliper bores. Lubricate cylinder walls and pistons with rust preventative oil, and install pistons, taking care not to twist piston when installing. Install dust seals and retaining rings, lubricating inner side of dust seals with rubber grease before installation.
Disassembly (Late Models) - Remove caliepr attaching bridge bolts and separate outer and inner caliper halves. Remove retaining ring and dust seal, apply compressed air to fluid inlet, and remove piston. Remove piston seal taking care not to damage caliper bore or seal groove.
Cleaning & Inspection - Clean all metal parts in trichlorroethylene, alcohol, or brake fluid; clean piston seal in brake fluid or alcohol; clean dust seal and other rubber parts in alcohol only. Inspect caliper bore and piston for wear, damage, or rust; replace parts as necessary. NOTE - Manufacturer recommends replacing piston seal and dust seal whenever piston has been removed.
Reassembly - Reverse disassembly procedure and note the following: Apply rubber grease to piston seal and brake fluid to piston when reassembling. If torque plate was remove from inner caliper half, clean torque plate shaft and shaft bore in caliper, then apply special rubber grease to rubber bushing, wiper seal inner surface, and torque plate shaft before reassembly. Tighten bridge bolts of caliper halves evenly.
Disassembly - Removedust boot, retaining ring, stop washer, and piston stop bolt, and withdraw primaryNOTE - Do not disassemble primary piston assembly. Remove check valve caps, tube seats, check valves, and check valve spring.
piston assembly, secondary piston assembly, and secondary return spring from master cylinder. 
Inspection - Check master cylinder bore and piston for wear or other damage and replace as necessary. Check clearance between cylinder bore and piston; if clearance exceeds .006", replace parts as necessary. Check all parts of secondary piston assembly; if any parts are found defective, replace complete secondary piston assembly.
Reassembly - Reverse disassembly procedure and note the following: Apply rubber grease to all parts (except boots) before reassembly. When assembled, check that return port is not block by piston cup when piston is located at return position.


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