Dipper ram lock valve 420-00004A Doosan, aftermarket

Dipper ram lock valve 420-00004A is an aftermarket part for the Doosan machines. According to the product card, this part is a dipper ram lock valve.

The stabiliser lock valve (hydraulic lock) is a dual pilot-operated check valve block in the stabiliser cylinder lines that traps the oil in the cylinder when the control is in neutral. This keeps the stabilisers from retracting under load while digging, so the machine stays stable. A faulty lock lets the legs creep up, makes the machine rock while digging and is a safety risk. The block is supplied new. The lock valve opens under pilot pressure from the control: it opens while the stabiliser is lowered or raised and closes when the lever is released, trapping the oil in the cylinder. The leg therefore stays put even if the engine stops or a hose is damaged. Each stabiliser has its own lock valve. The block body is steel; tighten the bolts evenly and make the hose joints with new seals. The block is supplied new with its ports capped. The block is light to handle.

Specifications

Compatibility

According to the product card, the part number is 420-00004A. The card also lists 410114-00154C. Fit is confirmed by the part number and the machine serial number. Other parts are in Backhoe arm.

Fitting

Check the joints for leaks after assembly.