4320 Hydraulic problem

[Zete]

Hello all,
I own a 1996 50th Anniversary Zetor 4320. Runs like a sewing machine in a tub of warm butter. Anyway, the loader has been getting weaker with time, doesn't want to stay lifted unless I hold the stick down and rev the engine. There are no visible leaks on the cylinders. Reservoir is full of hydraulic fluid. The loader is a Bush Hog 2445 QT. What should I check first? Thanks

 

[JackDaniels1982]

I don't know if it is too late to help or not? If there are no substantial leaks then to me I would be checking the control valve. It is possible that it is bypassing or "leaking" internally the same way a cylinder would. The way I would "test" this is to change the up/down with the bucket curl lines and see if it lifts better or the same. Another test that might help confirm, or bring information to light would be putting downpressure on it and lifting the wheels up. Does that work better/ does it settle in that position too? My other thought depending on how everything is plumbed is that the cylinder is leaking internally and the oil is bypassing. If it stayed the same with the curl, I would be looking at that. To test that with a bucket for the oil you could take off your downpressure/return hose and put it into a bucket. As you lift oil will come out, but after you have lifted it shouldn't come out anymore. If it continues to come out (as you hold the stick down and rev the engine) then internally your seals are done and the dust seal is just doing a really good job. You might also have better luck in another forum as it is likely not unique to Zetor. Hope this helps in some way.