I have acquired a Clark 4Ton forklift, was parked for 3 yrs. Finally got the engine running. There is a lot of little things still need to be taken care of, but at least it moves. Now, my main problem is , in the hyd. mast sys., it won't raise any kind of load but it's own weight and it won't hold or stay up. It drops down fast. My question is, could the problem be in the main cyl. seals or in the control valve? Thanks for any advise or help I can get.
All the forklift main cylinders I've seen are one way, so unless it's leaking a lot of oil onto the ground the cylinder is not the problem, it's either the valve, or the relief (in the valve). If you post a couple of pics of the cylinder we can help a little better. And post a couple of the valve too.