Rear control valve 332/Y3028 JCB 3DX, genuine

For the JCB 3DX backhoe loader: rear control valve 332/Y3028, a genuine JCB part.

This rear control valve controls the movements at the back of the JCB 3DX backhoe loader. In the mechanical version the spools are linked to the cab levers by rods and joints: moving a lever shifts its spool and sends oil to one side of the cylinder. Control valves come in several versions, differing in the number of sections and whether an extra hydraulic line is fitted, so compare the number, the section count and the port layout with the old block. The spools are lapped into the body with very small clearances, so when the body is worn a new spool alone does not help and the whole block is replaced. Dirty oil is the most common cause of scored spools. Check the lever joints as well: slack linkages stop the spool making a full stroke and weaken the services. The rear valve carries auxiliary relief valves (ARVs) protecting each cylinder line, while the main relief valve limits system pressure. When the block is changed, label the hoses and pipes, release the pressure and renew the sealing rings. After the new block is connected, run every service slowly through its full stroke to bleed the air and check the pressures with a gauge. The block is heavy; lift it with two people or a hoist.

Specifications

Compatibility

Other parts are in Hydraulic control valves.

Fitting

If the oil is dirty, clean the tank and renew the oil along with the block change, or the new spools will soon be scored.