TM  10-3930-643-34 HYDRAULIC  SYSTEM  TROUBLESHOOTING  AND  MAINTENANCE.  (cont) 12-1. Hydraulic  System  Troubleshooting.  (cont) MALFUNCTION TEST  OR  INSPECTION CORRECTIVE  ACTION g. NOISY  OPERATION. Step 1. Check hydraulic pump to determine if it is worn out or malfunc- tioning. Replace  hydraulic  pump,  refer  to  paragraph  12-2. Step 2. Check system relief valve spring or circuit relief valve spring(s)  for  possible  chattering  in  loader control valve, refer to paragraphs 12-3, 12-4, 12-5, 12-6 and 12-7. Replace  spring(s). h. HYDRAULIC OIL HEATING UP, Step 1. Check loader control valve relief valve(s) for insufficient valve pressure or pressure too high, refer to paragraph 12-3. Adjust  to  correct  pressure  setting. Step 2. Check  loader  control  valve  system  relief  valve  to  determine  if defective,   refer to paragraphs 12-3, 12-4, 12-5 and 12-6. Repair  loader  control  valve  and/or  relief  valve(s). Step 3. Check hydraulic pump to determine if it is worn out or malfunc- tioning. Replace  hydraulic  pump,  refer  to  paragraph  12-2. i. INSUFFICIENT  PUMP  PRESSURE  BUILD-UP. Step 1. Check hydraulic pump to determine if it is malfunctioning or worn out. Replace pump, refer to paragraph 12-2. Step 2. Check valve pressure on loader control valve and relief valve(s), refer to paragraphs 12-3, 12-4, 12-5, 12-6 and 12-7. Adjust  to  correct  pressure  setting. 12-6