I have a 2.5 ton engine hoist. it has worked fine the 2 months i have had it, lifting like it should. 2 days ago it stopped working right. with no load on it it will lift about 1 inch per pump of the handle. I put an 80lb weight on the end of a chain to lift, and it will only raise maybe 1/8 of an inch every pump. and it makes a whining sound when i pump. it is full of oil and i believe I have blead all of the air out. Do i just need to have the thing rebuilt?
the cylinder could be leaking internally. check the fluid again, check if you have no air. if it still wont work, its leaking inside. take it to be rebuilt, or return it for your money back
