TM 10-3930-671-24 Table 2-2.  Unit Troubleshooting Procedures - CONT. MALFUNCTION TEST OR INSPECTION CORRECTIVE ACTION ENGINE (CONT.) 8. ENGINE KNOCKING. Step 1. Bleed fuel system (Appendix F, Fuel System, Section 5.0), and prime fuel system (Appendix F, Diesel Fuel Injection System, Section 5.3). If engine still knocks, go to step 2. Step 2. Check that fuel type is correct type and not contaminated (VV-F-800). If fuel is incorrect type or contaminated, drain fuel tank and refill with correct/clean fuel. If fuel is OK, notify DS/GS maintenance. HYDRAULIC SYSTEM 9. NO LIFT, TILT, OR SIDESHIFT FUNCTION. Check hydraulic pump output pressure (Appendix F, Hydraulic System, Section 10.0). If hydraulic pump pressure is below 2500 psi (17237 kPa), adjust hydraulic pump (Appendix F, Hydraulic System Relief Pressure Check & Adjustment, Section 10.2). If hydraulic pump pressure is still below 2500 psi (17237 kPa), hydraulic pump is faulty.  Notify DS/GS maintenance. If hydraulic pump pressure is 2500 psi (17237 kPa), main hydraulic valve is faulty. Notify DS/GS maintenance. 10. LOAD CANNOT BE LIFTED TO MAXIMUM HEIGHT. Step 1. Check that upright assembly is adjusted correctly (Appendix F, Upright Maintenance, Section 13.0). If upright assembly is not adjusted correctly, adjust upright assembly (Appendix F, Upright Maintenance, Section 13.1). If upright assembly is adjusted correctly, go to step 2. 2-9