THE FOLLOWING INFORMATION is from TM9-768 (OCT. 1944) 45 TON TANK TRANSPORTER TRUCK – TRAILER M19. TM 9-768 45-46,Section XXXI,Maintenance Instructions,(46) SERVICE (AIR) BRAKE SYSTEM; { f. Brakes Release Slowly. }
(1) BRAKE CONTROL ROD NOT RETURNING PROPERLY. Check adjustment of control rod. Adjust if necessary (subpar. b (1) above).
Check condition of brake pedal pull-back spring. Replace spring if weak or broken. (2) RESTRICATION IN AIR TUBE OR HOSE.
Remove obstruction (subpar. e (4) and (9) above ) or replace faulty tube or hose. (3) DEFECTIVE APPLICATION VALVE. Replace defective valve (par.166). (4) BRAKE CAMSHAFT BINDING. Lubricate brake came with engine oil. DO NOT GET OIL ON LINING.
(5) BRAKES NEED ADJUSTING OR LUBRICATING. Adjust (par.176 b ) and / or lubricate (par.22) brakes. (6) OBSTRUCTION IN EXHAUST PORT OF BRAKE VALVE, QUICK RELEASE VALVE, OR RELAY VALVE. Remove obstruction. (7) DEFECTIVE BRAKE VALVE, RELAY VALVE, OR QUICK RELEASE VALVE. Replace defective valve (pars.166,170, and 172).
NOTE: I FOUND THIS INFORMATION ON WEB ; (search TM9-768).
INFORMATION FROM WIKIPEDIA : (search G159); MILITARY DIAMOND T TRUCK MODEL 981 {12 TON, 6×4, M20} was built on the SAME CHASSIS (as the MILTARY DIAMOND T TRUCK MODEL 980). MILITARY DIAMOND T TRUCK MODEL 981 CAME with open / or closed cab
and cargo box. THE winch could be used through the front and rear and was 20 feet longer. BOTH the Model 980 and 981 used a cab design similar to the 4 TON MILITARY DIAMOND T TRUCK.
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