2240 Hydraulics bleeding off

[THEPARTYHOUND]

The hydraulics on my tractor bleed off over a short period of time. If i lift a bucket of dirt, it will drop 3 inches a minute, or more. Same on the curl, same on the 3 point. How hard is that to fix and what would it entail?

 

[Tx Jim]

3 pt & loader boom/bucket cylinders leaking down although both are hydraulic they are not related. 3 pt problem could be leaking control valve from faulty seals or set too tight &/or faulty rockshaft piston seal. Repair of either requires R&R of rockshaft housing from tractor. RS valve clearance can be changed by removing a plug on RH side of RS housing then turning a screw. Loader boom settling is caused by worn control valve & repair requires valve replacement. Settling of bucket could be failed bucket cyl piston packings on 1 or both cylinders or worn out control valve

 

[THEPARTYHOUND]

The control valves shouldnt be too costly to replace?

 

[Zebrafive]

Do you have quick disconnects on the hoses from the valve to your loader?
If so, you could disconnect the hoses and see if the dropping stops. If it does, the valve is leaking. If it continues to drop, the cylinders are leaking internally. Be for warned disconnecting the hoses might be hard to reconnect, due to the pressure trapped in the lines.

The valve will be very expensive.

 

[Tx Jim]

Zebrafive
I have a question. Maybe I can't see the forest for the trees because I'm getting OLD!!!!!!

If 1 or both frt end loader boom cylinders are leaking at piston seals then for ""boom to lower"" piston must move in cyl barrel toward butt of cyl end therefore displacing a larger volume of oil into rod end of cyl barrel because rod occupies some of the area where does this oil go if rod seal is good & control valve isn't leaking internally IE how can boom lower???
Thanks,Jim

 

[Zebrafive]

Zebrafive
I have a question. Maybe I can't see the forest for the trees because I'm getting OLD!!!!!!

If 1 or both frt end loader boom cylinders are leaking at piston seals then for ""boom to lower"" piston must move in cyl barrel toward butt of cyl end therefore displacing a larger volume of oil into rod end of cyl barrel because rod occupies some of the area where does this oil go if rod seal is good & control valve isn't leaking internally IE how can boom lower???
Thanks,Jim

I see what you are say Tx Jim, I can't explain it. I am guessing the same way a shock absorber works, the oil somehow goes from the "butt" end to the rod end. I am thinking is the cylinder piston seals are shot, the oil can and will leak by.

 

[Tx Jim]

Just food for thought:
Referring to shock absorber the shaft is much smaller in size in relation to barrel size than a normal hyd cylinder. Boom barrel ID on JD 145 FEL is 2'' while rod OD is 1.48'' which doesn't leave a lot of room for the extra amount of oil that must enter rod end of cyl barrel if piston seal is leaking.

I think if FEL boom cyl piston seal is leaking cyl will hydraulically lock before piston moves very far into barrel if control valve isn't leaking internally.

 

[THEPARTYHOUND]

No quick disconnects on valve; the hoses thread in. The cylinders do leak a bit around the shaft, but it is really just a slight seepage. Is there a way to tell for sure if the cylinder is leaking internally? There is a guy locally that rebuilds cylinders, but not valves to the best of my knowledge. Guess i could ask him...

 

[Tx Jim]

You can disconnect hose from end of cylinder that piston has fully traveled,leave orifice open,apply hyd pressure to other end of cyl & if piston packing(seal) has failed oil will exit open orifice.

 

[THEPARTYHOUND]

Ok, that makes sense. Do i need to have the cylinder fully extended to do this? Theres not going to be a lot of pressure on the hose when i take it off is there?