I have a New Holland L220 Skid steer that will not lift like it should . We have tested main hydraulic pressure and flow which is good . We have also tested the boom section of the valve, testing for port relief problems . It builds proper pressure on the boom circuit . The boom does not leak down . Any ideas ?
Not sure it applies here, but is drive to the pump slipping?
What is your hydraulic pressure and flow readings? What are you trying to lift that it will not lift? Sometimes the main relief has a much lower cracking pressure than full flow pressure. This will make its lifting power weak. Check that if flow and pressure were within spec.
Ok we have already checked the main relief and it is within spec 3000 psi. We have a pump flow of 19GPM on the auxiliary hydraulics and on the loader valve . I didn't check about pump drive slipping but it does build correct main pressure .
What is the cracking pressure of the main relief? if pump was slipping, it should do it during your flow tests.
Cracking pressure is 2995 psi to be exact , about the pump slipping exactly my thoughts if it builds correct pressure on a test why would anything slip when working . I work hydraulic repairs specifically on skid loaders all the time but I must be missing something here . I will need to find out the exact weight of what my customer is trying to lift . He says he could lift whatever it is with his old LS170 with has an operating load spec of 1765 lbs. and the L220 has operating load of 2000 lbs. ???
I would find out what the operator is trying to lift first. Try another machine if you have one to compare. I'm assuming that this unit has the EH controls. Maybe the operator is doing something wrong. Maybe ride control is on. Maybe self leveling is acting up. Try leaving that off. Maybe has leakage in one of those valves. Perhaps you should flow test at the lift cylinders?
^ You say 'boom does not leak down' _ but is that with any amount of Weight/ Pressure on it, or Empty test only..?? Depending upon your answer to that, it may well be that you have a leak across ram seals internally _ although I am just a 'dumb farmer' at heart in many instances, it seems the simplest answer to me now, given what you have checked and informed us upon otherwise.. Good Luck!!
X2 on internal cylinder leak. Are pins and bushings greased and free?