BRAKE ADJUSTMENTS.

Note

m a y b e p e r f o r m e d when pressure bleeding

e q u i p m e n t is unavailable. Manual bleeding will

The parking brake must be capable of

require two men, one to depress and hold the

holding truck, with rated capacity load, on

brake pedal while the other opens and closes the

a 15% grade, If a major adjustment as

bleeder valves. Proceed as outlined under pressure

described in paragraph 4-30 will not restore

bleeding,

but observe the following special

proper operation, the parking brake linings

instructions:

should be replaced. See Section V.

4-22. It must be remembered that the brake pedal

a. Fully apply hand brake, moving lever from full

should be depressed slowly and held until the line

forward to full rearward position. Cable tension

connections or bleeder screws are securely

should be sufficient to require a definite effort in

tightened. This prevents the possibility of air being

pulling the lever over the center position.

drawn into the system during the bleeding

operation. Check the master cylinder reservoir level

b. With hand brake set, start truck engine and

often during manual bleeding and keep within l/4

place directional control lever in forward position.

inch from the top.

c. Depress engine throttle until engine runs up to

4-23. With filler cap off the master cylinder,

maximum stall speed (approximately 1500 RPM).

depress and release brake pedal. A small

Truck should not move or creep.

d i s p l a c e m e n t of fluid should be noticed in the

cylinder reservoir. If this happens, the brake pedal

d. If either of the above tests indicate a need for

(upon being released) is returning the master

a d j u s t m e n t , perform the minor adjustment first

c y l i n d e r piston to its normal position to open a

a n d recheck brake action. Then, if necessary, a

master cylinder port. This port must be open.

major adjustment should be performed.

4-24. If fluid is not displaced upon releasing the

4-29. MINOR ADJUSTMENT. Minor adjustment

brake pedal, a pedal adjustment is required.

to the parking brake linkage is made by placing the

lever in the full forward (released) position, then

4-25. BRAKE ADJUSTMENTS.

turning the knurled knob on the end of the lever

several turns clockwise. After making this

4-26. When the brake system is operating

adjustment, recheck brake action as described

properly, the cam like action of the reaction arm

above. If necessary, repeat adjustment.

allows self-adjustment for the total thickness of the

brake linings, without any noticeable increase in

Note

brake pedal free travel. The self-adjustment feature

eliminates the need for manual adjustment of the

brakes.

If brake effectiveness cannot be restored

within the range of travel of the lever knob,

4-27. When the brake linings become worn beyond

a major adjustment must be performed.

their designed limits, there will be a noticeable

change in the brake pedal effort required to stop

4-30. MAJOR ADJUSTMENT. When minor

adjustment is not sufficient to restore brake

the machine or, brakes will become noisy during

application. If either of these conditions exist, the

efficiency, a major adjustment should be

axle ends should be removed so an inspection of

performed as outlined below:

the brake linings can be made to determine their

further serviceability. If lining replacement appears

a. Release hand brake lever, returning lever to the

necessary, refer to Section V.

full forward position.

4-28. PARKING BRAKE CHECK AND ADJUST-

b. Rotate knurled knob on the end of the lever

MENT. Periodic checks to determine efficiency of

counterclockwise as far as possible, and pull lever

t h e parking brake are to be made as described

rearward to the applied position.

below.

4-26