MAIN CONTROL VALVE MAINTENANCE

TM 10-3930-660-24-1

MAIN CONTROL VALVE MAINTENANCE

0175 00

THIS WORK PACKAGE COVERS

Removal, Installation, Adjustment of Main Relief Valve, Adjustment of Boom Extend Relief Valve, Adjustment of Boom

Hoist Relief Valve, Adjustment of Boom Lower Relief Valve

INITIAL SETUP

Personnel Required

Tools and Special Tools

Tool kit, general mechanic's (Item 39, WP 0324 00)

Two

Shop equipment, common no. 1 (Item 20, WP 0324

Equipment Condition

Materials/Parts

Vehicle on level ground (10-3930-660-10)

Cap and plug set (Item 8, WP 0323 00)

Boom placed in horizontal position and supported

Sealant, Loctite (Item 43, WP 0323 00)

with rigid chocking (TM 10-3930-660-10)

Tag, marker (Item 57, WP 0323 00)

Lockwasher (5)

Transmission cover removed (WP 0150 00)

WARNING

When working under the boom, always use blocks or other supports. Combined weight of boom and

MLRS attachment is approximately 6,300 lb (2858 kg). Failure to adequately support the boom could

result in severe injury or death.

Do NOT remove hydraulic tank filler cap or disconnect or remove any hydraulic system line or fitting

unless hydraulic system pressure has been relieved. Hydraulic system pressure can be over 3,000 psi

(20685 kPa), even with engine and pump OFF. To relieve pressure, lower all hydraulic attachments to

the ground and shut down engine. Move control levers through all operating positions, then SLOWLY

loosen hydraulic tank filler cap. After maintenance, tighten all connections before applying pressure.

Escaping hydraulic fluid under pressure can penetrate the skin, causing injury or death.

At operating temperature hydraulic oil is hot. Allow hydraulic oil to cool before disconnecting any

hydraulics. Failure to do so could result in injury.

CAUTION

Wipe the area clean around all hydraulic connections to be opened during removal and disassembly. Cap oil

lines and plug holes after removing lines. Contamination of the hydraulic system could result in premature

failure.