JD hydraulic

myjohndeere2022 · Mar 19, 2022

I have a JD 4400 series with a 430 loader bucket will go up and down but not with any weight in it , fluid level is good and this happened all of a sudden, Thanks for the help in advance!

Kyle_in_Tex · Mar 19, 2022

So many possibilities.

Can you use the down motion to lift the tractor's front wheels up? Air in system possibly?
Hydraulic pressure OK? Possible pump problem.
Do bucket curl cylinders still have power?
If so, maybe time to rebuild lift cylinders. Probably all 4 cylinders.

Buna N rubber only lasts about 15 years. If your loader has not been rebuilt, it might be time to do it.

Leejohn · Mar 19, 2022

Make sure 3pt not all the way up, relief valve stuck open.

LD1 · Mar 20, 2022

Ditto what leejohn said. Sometimes the feedback linkage is slightly out of adjustment and when all the way up it will do some strange things to the loader.

So try lowering the 3ph and see if there is any change.

If not....you need to get a pressure gauge for starters

myjohndeere2022 · Mar 21, 2022

Kyle_in_Tex said:
So many possibilities.

Can you use the down motion to lift the tractor's front wheels up? Air in system possibly?
Hydraulic pressure OK? Possible pump problem.
Do bucket curl cylinders still have power?
If so, maybe time to rebuild lift cylinders. Probably all 4 cylinders.

Buna N rubber only lasts about 15 years. If your loader has not been rebuilt, it might be time to do it.

No I haven’t checked pressure yet , I pulled out pressure relief valve and no debris and moves freely , I will check pressure tonight and change filter, it does not have any down pressure either won’t lift front off ground , how much pressure should I be reading when I connect gauge? Thanks!

myjohndeere2022 · Mar 21, 2022

Leejohn said:
Make sure 3pt not all the way up, relief valve stuck open.

Ok thanks I’ll try that

Kyle_in_Tex · Mar 23, 2022

myjohndeere2022 said:
No I haven’t checked pressure yet , I pulled out pressure relief valve and no debris and moves freely , I will check pressure tonight and change filter, it does not have any down pressure either won’t lift front off ground , how much pressure should I be reading when I connect gauge? Thanks!

Pressure will vary with engine rpm and the heat of the oil, but you should probably have up to 2000-2500 psi if I'm remembering correctly? Verify that amount of pressure before you do anything else.