TM10-3930-660-20 8-51. HYDRAULIC BYPASS SWITCH - REPLACE/TEST This task covers: a. Removal b.  Installation c. Testing Initial Setup Tools Materials/Parts Shop  Equipment,  Automotive Container, 1 gal. Maintenance and Repair, Common #2 Loctite 59241 (App. C, Item 42) Less Power Cap and Plug Test  Equipment Ohmmeter Voltmeter Set Personnel  Required Two  Personnel Equipment  Condition Reference Vehicle parked on level ground. TM10-3930-660-10 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 tank by loosening filler cap very slowly. Failure to follow these precautions could result in serious personal injury. CAUTION Wipe the area clean around all hydraulic connections to be opened during removal and disassembly. Cap out lines and plug holes after removing lines. Contamination of the hydraulic system could result in premature failure. WARNING 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. CAUTION Wipe the area clean around all hydraulic connections to be opened during removal and disassembly. Cap out lines and plug holes after removing lines. Contamination of the hydraulic system could result in premature failure. 8-160