TM10-3930-660-20 18-12. HYDRAULIC JOYSTICK CONTROL VALVE - REPLACE This task covers: a. Removal b. Installation Initial Setup Tools Tool Kit, Automotive Mechanics Materials/Parts Container, 6 Gal. Lockwashers  (10) Equipment  Condition Loctite 242 (App. C, Item 39) Vehicle parked on level ground. Tags (App. C, Item 51) Transmission cover removed, para.  16-6. WARNING Hydraulic oil in the system can be under pressures over 3000 psi with the engine OFF. ALWAYS relieve pressure in hydraulic lines before attempting to remove any component in the hydraulic system. With engine OFF, starter switch in RUN position, and MLRS attachment on the ground, move control levers through all operating positions several times to relieve line pressure. Relieve pressure in hydraulic oil reservoir by loosening filler cap very slowly. Failure to follow these precautions could result personal injury. WARNING in  serious CAUTION Wipe area clean around all hydraulic connections to be opened during removal. Cap lines and plug openings after removing lines. Contamination of hydraulic system could result in premature failure. If more than one hydraulic line is to be removed, identify lines to assure proper  installation.  Use  suitable container to catch any hydraulic oil that may drain from system. At operating temperatures, hydraulic oil is hot and under pressure. Hot oil can cause injuries. Allow hydraulic oil to cool before disconnecting any hydraulic lines. 18-48