Hydraulic tank cap, non-locking 123/04055 JCB 3CX/4CX, aftermarket

Hydraulic tank cap, non-locking 123/04055 is an aftermarket part for the JCB 3CX and 4CX backhoe loaders.

This non-locking hydraulic tank cap closes the filler neck and lets the tank breathe. In the JCB catalogue the non-locking cap 123/04055 has been replaced by the lockable filler and breather cap 333/Y1376, and both fit the same filler neck. The breather lets the tank breathe as the cylinders move and limits dust entry. Replace a cap whose seal has hardened or whose breather is blocked, since a blocked breather creates a vacuum in the tank and makes it harder for the pump to draw oil. The aftermarket cap is made to the filler neck size of the original. The part is chosen by part number and compared with the old one before fitting.

Specifications

Compatibility

Lockable cap: 333/Y1376. Other parts are in Hydraulic tanks.

Fitting

Before changing the valve, release all system pressure, lower any loaded equipment and clean around the valve so no dirt enters the cavity. After removing the old valve, clean the O-ring remains out of the cavity. Oil the new valve's O-rings with clean hydraulic oil, start it by hand and tighten it to the specified torque. With the engine running, test the function first without load, then under load, and check the joint for leaks.