TM 10-3930-671-24 Table 2-2.  Unit Troubleshooting Procedures - CONT. MALFUNCTION TEST OR INSPECTION CORRECTIVE ACTION HYDRAULIC SYSTEM (CONT.) 21. LOAD WILL NOT HOLD (DOWNDRIFT). Step 1. Check levers and linkage for correct adjustment. If levers or linkage are not adjusted correctly, adjust or replace levers (Appendix F, Main Hydraulic Control Valve, Section 10.5). If levers and linkage are OK, go to step 2. Step 2. Check lift cylinder for seeping that would cause downdrift (Appendix F, Upright Mainte- nance, Section 13.0). If lift cylinder is seeping, repair lift cylinder.  Notify DS/GS maintenance. If lift cylinder is OK, replace main hydraulic control valve.  Notify DS/GS mainte- nance. 22. LOAD DROPS WHEN SPOOL IS MOVED FROM NEUTRAL TO A POWER POSITION. Relief valve faulty. Replace relief valve (located in main valve), notify DS/GS maintenance. SERVICE BRAKE SYSTEM 23. NO BRAKE PEDAL. Step 1. Check brake wheel cylinders for external leaks (Appendix F, Transaxle, Section 7.0). If wheel cylinders have external leaks, replace wheel cylinders (Appendix F, TA18 Transaxle, Section 7.6). If wheel cylinders are OK, go to step 2. Step 2. Cap master cylinder exit port and check brake pedal firmness. If brake pedal is not firm, replace brake master cylinder (Para 3-29). If brake pedal is firm, go to step 3. 2-14