TM  10-3930-638-24&P 2-55.  HYDRAULIC  LIFT  SYSTEM  TROUBLESHOOTING  (cont) MALFUNCTION TEST  OR  INSPECTION CORRECTIVE ACTION 3. UNABLE TO LIFT, TILT, SHIFT OR ROTATE LOAD (cont) Step 3. Remove strainer from hydraulic reservoir and check for blockage (para 2-56g(3)). a. If hydraulic reservoir strainer is clogged, clean (para 2-56g(3)). b. If hydraulic reservoir strainer is okay, proceed to step 4. Step 4. Check setting of relief valve (para 248b(2), step 20). a. Adjust pressure relief valve if setting is not 2500-2550 PSI (para 248 b(2), step 23). b. If pressure relief valve setting is okay, proceed to step 5. Step 5. Check for contaminated oil. Start engine and operate at idle speed. Place lift control lever in RAISE position and hold until tube located as shown below feels warm to touch (mast will be at full height). Remove hydraulic reservoir oil filler and take an oil sample: If hydraulic oil is contaminated as indicated by oil feeling gritty, milky color, or oil is dark and thick or smells scorched, drain and flush hydraulic system, clean strainer, and replace oil filter (para 2-56g). 2-391