New Holland L190 boom drifts down fast

I have a New Holland L190 with pilot controls. The boom drifts down fast. I Have repacked the lift cyls and found no problems there. Does anyone know if there is a lift lock valve, check valve that could be causing this? Any help or ideas would be appreciated.

Thanks.

Does the boom drift down with the machine off? With the machine controls off? What year is it?

Does your machine have ride control or float? Those valves could be faulty.

Other than that, its not likely, but you could have too much leakage in the control valve or your pilot valve is sticking.

Thanks for the reply Gary.

The machine is an 06, it drifts down with the machine or controls on or off.

I located the problem tonight the emergency lowering control valve below the seat was partially bypassing, nothing a #8 jic plug and cap couldn't fix. No more drift.

Thanks again for the help.

You may want that in case you loose power and need to drop the boom.

Repacking cylinders is one of the last steps for cylinder drift, people do it first all the time though. You could take the seals completely out of the cylinder and it will not drift down on its own. The rod end can't accept any fluid from the blind end, thus something outside of the cylinder is causing it to drift down (some sort of control along the fluid path). Leaking piston seals could cause it to drift up though.