TM 10-3930-659-20 Table 4-3.  Hydraulic Troubleshooting (Con't). MALFUNCTION TEST OR INSPECTION CORRECTIVE ACTION Step 2.  Check forklift control valve for sticking or damage. Replace sticking or damaged forklift control valve (see paragraph 17-8). 8.  HYDRAULIC FLUID OVERHEATS. Step 1.  Inspect transmission oil cooler for clogged fins. Remove all exterior restrictions from transmission oil cooler. Step 2.  Inspect hydraulic system lines and hoses for dents or twists. Replace damaged lines or hoses (see paragraph 17-14,17-15, 17-16, 17-17, 17-18, 17-19, 17- 20, 17-21, 17-22, 17-23, 17-24, 17-25, 17-26, 17-27, 17-37, 17-38, or 17-39). Step 3.  Test fork/brake hydraulic pump standby pressure (see paragraph 17-3). Adjust fork/brake hydraulic pump standby pressure (see paragraph 17-3). Replace damaged fork/brake hydraulic pump (see paragraph 17-5). Step 4.  Test main hydraulic pump flow (see paragraph 17-1). Replace damaged main hydraulic pump (see paragraph 17-6). 9.  HYDRAULIC FLUID FOAMS. Step 1.  Check hydraulic fluid for contaminants. Drain hydraulic reservoir (see LO 10-3930-659-12), replace hydraulic reservoir suction filter (see paragraph 17-29) and hydraulic oil return filter (see paragraph 17-31), and fill hydraulic reservoir with hydraulic fluid (Item 19, Appendix C) (see TM 10-3930-659-10). Step 2.  Check for foamy hydraulic fluid and leaking hydraulic lines, hoses, and fittings. Tighten all lines, hoses, and fittings. Replace worn or leaking preformed packings, lines, hoses, or fittings (see paragraph 17-14, 17- 15, 17-16, 17-17, 17-18, 17-19, 17-20, 17-21, 17-22, 17-23, 17-24, 17-25, 17-26, 17-27, 17-37, 17-38, or 17-39). STEERING SYSTEM 10.  SLOW OR HARD STEERING. Step 1.  Test priority valve relief pressure (see paragraph 12-27). Adjust priority valve relief pressure (see paragraph 12-27). Replace damaged priority valve (see paragraph 12-28). 4-39