TM  10-3930-638-24&P 2-41.   BRAKE   SYSTEM   TROUBLESHOOTING   (cont) MALFUNCTION TEST  OR  INSPECTION CORRECTIVE ACTION 4.  SERVICE  BRAKES  GRAB Step 1. Check source of brake fluid to ensure that brake fluid is correct; also check for contaminated brake fluid. a. If incorrect brake fluid was used or if brake fluid is contaminated, drain brake system of brake fluid and refill using correct brake fluid (refer to current lubrication order) (para 2-43a). b. If brake fluid is okay, proceed to step 2. Step 2. Check  brake  pedal/return  spring  linkage  for  binding,  interference,  missing  parts,  or  damage  (para  2-43e). a. If brake pedal/return spring linkage is binding, has interference, is missing parts or damaged, repair or replace (para 2-43e). b. If brake pedal/return spring are okay, proceed to step 3. Step 3. Check hydraulic brake valve for damage/leaking condition (para 2-43c). a. If hydraulic brake valve is damaged or leaking, repair or replace it (para 2-43c). b. If hydraulic brake valve is okay, proceed to step 4. Step 4. Place blocks (6 by 6 by 18 inches wood blocks) at each wheel to prevent vehicle from moving. Remove  shipping  lock  pin  from  storage  area  under  operator’s  seat  (para  2-4b(1))  and  install  in  chassis. Ensure that parking brake is in released position. WARNING Before raising axle off ground, be sure that shipping lock pin is installed. Failure to do so may cause vehicle to turn and slip off jack or jack stands causing serious injury or death. If you are injured by falling equipment, obtain  medical  aid  immediately. Raise one axle and wheels off ground. Rotate wheel by hand; there should be a very slight dragon wheel. Repeat  above  for  remaining  wheel  and  axle. a. If there is a very slight drag on wheels, proceed to step 5. b. If there is excessive dragon wheels, adjust brakes (para 243a). Step 5. Remove axle shafts and hub and drum assemblies from one axle (para 2-39f). Check brake shoe return spring (para 243a). Repeat  above  for  remaining  axle. a. If brake shoe return spring is permanently set, replace (para 2-43a). b. If brake shoe return spring is okay, proceed to step 6. 2-263