TM10-3930-660-20 18-27. HYDRAULIC TUBING - REPLACE This task covers: a. Removal b.  Installation Initial Setup Tools Materials/Parts Shop  Equipment,  Automotive Caps Maintenance, Common #2 Less Power Container, 1 Gal. Lockwasher  (5) Cap and Plug Set Equipment  Condition Vehicle parked on Wheels chocked. level  ground. 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 in serious personal injury. 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. 18-113