John Deere 5720 loose hydraulic power when oil gets hot..

[knutmartin]

Hi

I have a 2003 John Deere 5720, that loose hydraulic power after about 15minutes, it will not lift heavy equiment at all.
Everything works fine when its is cool, but start to struggel as soon as the oil gets hot.

Changed oil and filter when the issue appared, everything looked fine for the first 15min, before it stopped working. Measurred the presaure in the valve and it showed 150bar and dropped to 100bar after 15-20 minuttes.

Any ideas?

-Knut Martin

 

[Tx Jim]

Be sure all control valves especially the 3 pt control valve is in neutral.

 

[J_J]

Hi

I have a 2003 John Deere 5720, that loose hydraulic power after about 15minutes, it will not lift heavy equiment at all.
Everything works fine when its is cool, but start to struggel as soon as the oil gets hot.

Changed oil and filter when the issue appared, everything looked fine for the first 15min, before it stopped working. Measurred the presaure in the valve and it showed 150bar and dropped to 100bar after 15-20 minuttes.

Any ideas?

-Knut Martin

Hot oil will sneak by worn parts more readily .

What temp is the oil when hot.

Should not be over 200 degrees.

 

[bigdeano]

Hi

I have a 2003 John Deere 5720, that loose hydraulic power after about 15minutes, it will not lift heavy equiment at all.
Everything works fine when its is cool, but start to struggel as soon as the oil gets hot.

Changed oil and filter when the issue appared, everything looked fine for the first 15min, before it stopped working. Measurred the presaure in the valve and it showed 150bar and dropped to 100bar after 15-20 minuttes.

Any ideas?

-Knut Martin

Are you saying the problem started after you changed the oil? Maybe you need a heavier grade oil because it's getting too thin.

 

[knutmartin]

Thank you for your input guys.
The tractor is at the dealer to get it sorted, as we need it ran out of time sorting it out ourself.
So far they havent found anything wrong, besides the nr21 small piece was maybe a little out of place (I dont see how thats possible),
http://www.tractorbynet.com/forums/...-5720-2003-model-py018827_______un27oct09-gif

TxJim, I am pretty sure they all were in neutral (if you talk about the handles inside the cab).

J_J , I didnｴt measure the temp, but I do not think it could reach 200 degrees in the sort time it was running.

Big_deano, The problem started before I changed oil, 2 weeks after I disconnected the front loader. And looked like ti was sorted when i took it for a short test run, but when it was put to work the problem started again. The oil is a type we use on 3 different deeres and is recommended by the dealer, so that should also be ok.

 

[J_J]

150 bar = 2175.566070105 psi

100 bar = 1450.3773800699998 psi

A flow and pressure test set will tell you the condition of the pump.

An hyd shop can do the test.

 

[knutmartin]

Latest news from the dealer is that it was a o-ring (nr 5 or 21 or nr 7 in the picture at he end of this post) http://www.tractorbynet.com/forums/...-5720-2003-model-py018827_______un27oct09-gif that was slightly misplaced.

The will change all of them and we will know by the end of the day if that was what caused the problem. I find that strange, it is more than two weeks from I removed the end cover when I disassembled the front-loader.

Correction to my earlier post, from what I understand it was the nr 6 in this diagram that was slightly misplaced.


Last update:
The tractor is up and running , giving 200bar after the workshop changed o-rings, cleaned and mounted the selection valve block together. They said it was rust at some of the faces between the section, and assume it had not been tightened enough at some point letting water penetrate in between the section and make them rust and then cause internal leakage.

I hope the tractor feels better than ever no as it never have been 100%, and wish I have done the "clean-up" myself......