Load Check Valve In Control Valves May Need To Be Retorqued In Order To Provide Correct Load Sensing Signal Caterpillar

Load Check Valve In Control Valves May Need To Be Retorqued In Order To Provide Correct Load Sensing Signal

Usage:

EXCAVATORSM312 (6TL1-UP),
M315 ( 7ML1-UP),
M318 (8AL1-UP, 6ES1-UP, 8SS1-UP),
M320 (6WL1-UP, 9PS1-UP) EXCAVATORS

Problem:

The load check valves in the main control valve block, and the attachment control valves for the auxiliary circuits, may have the incorrect torque. If the load check valve is not tightened to the recommended value of 150 N·m (110 lb ft), the threads on the check valve can loosen and deteriorate the valve itself. As a consequence, the corresponding implement can not build up a load sensing pressure and in turn will be unable to operate.

Solution:

If there is one implement that cannot be activated and the source of the problem is not located in the main hydraulic system or the pilot system, inspect the main control valve for that implement. If the load check valve for the control valve is loose and/or damaged, replace the control valve with a new one.

NOTE: Refer to the illustration on Page 2 for the location of the load check valve.

Location of load check valve (1).

COPYRIGHT 1999 CATERPILLAR ALL RIGHTS RESERVED

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