TM 10-3930-671-24 3-33. HYDRAULIC OIL FILTER BASE ASSEMBLY REPAIR. a. Removal. (1) Disconnect batteries (Para 3-25). (2) Operate hydraulic control valve levers to relieve all pressure from hydraulic system. (3) Remove valve control cover (Para 3-36, Step a [11]). WARNING Hydraulic fluid is slippery and can cause personal injury when spilled on a floor or other smooth surface.  Precautions should be taken to avoid any spillage and to clean up any spills when they occur. (4) Remove hydraulic oil filter (1) from base (2). (5) Remove two screws (3) and base (2) from bracket (4). (6) Remove two clamps (5) and hoses (6) from two fittings (7). (7) Remove two fittings (7) and seals (8) from base (2).  Discard seals. 3-92