Figure 4-46. Adjusting Pedal Free Travel

TM 10-3930-633-12

lining wear and excessive fuel consumption.

(3) Loosen locknut.

Using a ruler, measure brake pedal free travel.

(4) Rotate clevis to obtain specified pedal free

(Depress pedal by hand.) Clearance should be

travel.

measured from top pedal position to where the

(5) Tighten locknut to hold adjustment.

pedal meets resistance from the master cylinder.

(6) Reinstall clevis pin and cotter pin.

When pedal meets resistance from the master

(7) If the brake pedal travels beyond the free

cylinder, the distance traveled should be to

travel distance, this could indicate either of the

of an inch. If the free travel is incorrect, adjust as

following conditions:

follows:

(a) Lack of fluid in the reservoir.

(1) Locate the pedal to push rod connecting

(b) Air in the brake system lines.

link, shown in figure 4-46.

(2) Remove cotter pin and clevis pin from one

replacement.

end of this connecting link.

Figure 4-46. Adjusting Pedal Free Travel

tighten all hydraulic connections and bleed

c. Power Brake System Test. As a system

screws. Apply pedal again and if pedal again falls

check, apply brakes several times with the engine

away to floor, there is a hydraulic leak in the

off and car standing still. Hold the brake pedal

system. Locate and repair leak.

applied firmly and start the engine. The brake

(3) If pedal is spongy, bleed remaining air out

pedal should drop or "fall away" slightly under

of hydraulic system.

steady pressure but then should remain firm

d. Fluid Leakage Check. The general routing

without further travel or sponginess.

of all the brake system tubing is shown in figure

(1) If pedal fails to "fall away," check

4-47. Check at each connector for loose fittings,

vacuum hose connection.

cracks, or signs of leakage, and replace damaged

(2) If pedal continues to fall, check and