Brake Master Cylinder - TM-10-3930-624-120091

deterioration of rubber parts, signs of leaking, or other

(3) Remove the clevis pin securing the push

damage; replace damaged wheel cylinders.

rod to the brake pedal assembly and disconnect tension

(6) Inspect the brake return springs for

spring (refer to fig. 4-52).

cracks, worn or damaged end hooks, or elongation. If

the springs are damaged or if they are elongated so that

spaces exist between loops of the springs, replace the

springs.

(7) Inspect the backing plate for cracks,

distortion, and other damage; replace authorized parts.

Note. The brake drum is an integral part of

the drive wheel.

(8) Inspect brake drum interior for scoring,

charring, or uneven wear. Replace the brake drum as

directed in paragraph 4-55.

c. Reassembly and Installation.

(1) Attach the adjuster assembly to the brake

shoes with the roll pins.

Figure 4-52. Pedal lash adjustment.

(2) Make certain the backing plate is secured

tightly to the axle.

(4) Remove the capscrews holding the

(3) If self-adjusting

link is inadvertently

master cylinder to the inside of the frame and remove

disassembled, it must be replaced.

the cylinder.

(4) Install the shoe and link assembly in place

b. Cleaning and Inspection.

and install the springs. Install the wheel assembly as

(1) Clean exterior of master cylinder with a

directed in paragraph 4-55.

cleaning solvent.

(2) Inspect the master cylinder for cracks,

4-52. Brake Master Cylinder

leaks, faulty operation, or other damage; replace if

a. Removal.

damaged.

(1) Remove the floor plate.

c. Installation. Install the master cylinder in the

truck by reversing the removal procedure.

Note. Check to make sure engine ground strap

is connected:

4-53. Pedal Linkage

If the pedal linkage does not provide proper clearance

between master cylinder piston and linkage with the

brakes released, the piston cannot return to full off

position. The brakes will drag after several applications

if the by-pass port is blocked. Refer to figure 4-52.

Adjust the linkage to provide 1/2 inch of free play

measured at the brake pedal by loosening the locknuts

and adjusting the adjusting nut. More free play will

reduce the usable stroke of the master cylinder piston.

Figure 4-51. Master cylinder.

4-43