Deere 9520 hydraulic issue

[MikeKnapp]

Hi all,
This is a "hail mary" to all you Deere experts out there......I'm from the UK and run a large onion farm in Senegal, West Africa and my 9520 has a serious problem. The original hydraulic pump blew towards the end of last year (how, I do not know) but it was replaced by a non original Deere pump which did not work and got so hot that the hydraulic tank above it melted so they managed to get an original and it was fitted properly. Pressure leaving the pump is 2000psi + so all good from the pump but when trying to steer left or right the hydraulic cylinders seem to be fighting against each other and I cannot work out why and I am worried that if I carry on its going to do a lot of damage.....I've tried plugging in a rear spool to see if that helps but it does nothing.....
From what I can understand the hydraulic pump itself always gives the steering priority over any other action so could it be a sensor or load compensator issue and if yes, where do I try and find it as I have no 9520pst hydraulic diagram.....I can email you a video of the problem if you need it......
Can anyone please send me a hydraulic diagram / drawing ?
Can anyone help please and if yes, send me a PM and we can exchange info.....
Many thanks in advance

 

[oldnslo]

By fighting when turning do you mean it is hard to turn the steering wheel or the steering wheel is jerky?

If yes Can you install a pressure gauge in the pressure line between the priority valve and steering unit? This should remain at some pressure while trying to turn. If it does not I would double check pressure before the priority if possible along with pressure to steering.

If this has the priority valve that I am thinking of it would have several small orifices and a relief valve in the priority valve along with priority spool. An orifice plugged or binding priority valve spool could prevent the flow from getting to the steering unit causing it to turn hard or jerk.

Deere TM1972 is what Deere shows for the service manual on the 9520.

 

[MikeKnapp]

By fighting when turning do you mean it is hard to turn the steering wheel or the steering wheel is jerky?

If yes Can you install a pressure gauge in the pressure line between the priority valve and steering unit? This should remain at some pressure while trying to turn. If it does not I would double check pressure before the priority if possible along with pressure to steering.

If this has the priority valve that I am thinking of it would have several small orifices and a relief valve in the priority valve along with priority spool. An orifice plugged or binding priority valve spool could prevent the flow from getting to the steering unit causing it to turn hard or jerk.

Deere TM1972 is what Deere shows for the service manual on the 9520.

By fighting when turning do you mean it is hard to turn the steering wheel or the steering wheel is jerky?

If yes Can you install a pressure gauge in the pressure line between the priority valve and steering unit? This should remain at some pressure while trying to turn. If it does not I would double check pressure before the priority if possible along with pressure to steering.

If this has the priority valve that I am thinking of it would have several small orifices and a relief valve in the priority valve along with priority spool. An orifice plugged or binding priority valve spool could prevent the flow from getting to the steering unit causing it to turn hard or jerk.

Deere TM1972 is what Deere shows for the service manual on the 9520.

Hello and thanks for your info and help. Ok, I turned the tractor on today (tickover) and took a oil pressure measurement from the P position on the top of the spool block and it read zero bar when it should read 80bar on tickover......

 

[MikeKnapp]

By fighting when turning do you mean it is hard to turn the steering wheel or the steering wheel is jerky?

If yes Can you install a pressure gauge in the pressure line between the priority valve and steering unit? This should remain at some pressure while trying to turn. If it does not I would double check pressure before the priority if possible along with pressure to steering.

If this has the priority valve that I am thinking of it would have several small orifices and a relief valve in the priority valve along with priority spool. An orifice plugged or binding priority valve spool could prevent the flow from getting to the steering unit causing it to turn hard or jerk.

Deere TM1972 is what Deere shows for the service manual on the 9520.

Hello oldanslo, thanks for your info and help. Ok, I turned the tractor on today (tickover) and took a oil pressure measurement from the P position on the top of the spool block and it read zero bar when it should read 80bar on tickover if running correctly and a little over 200bar from any of the spools......also when turning the steering wheel it does jerk but there is resistance to the turning motion. Simply put, it doesnt feel or sound right and its worrying me.....I have no manual or drawings of the hydraulic system and I'm in big trouble.....can you advise where I can get some drawings of the hydraulics for this machine ?

 

[oldnslo]

The Deere service manual part number TM1972 would schematic as well as test or diagnostic instructions for the complete tractor. Deere shows $180 to download not sure on price for paper version.

 

[MikeKnapp]

How do I find the link to this website please....can I simply go online, pay the fee and download ?
Many thanks

 

[oldnslo]

I believe website was Deere manuals.com

Yes I believe anyone can go online and order the manual.

Possibly try a search for the manual number. Sorry but Not sure how things work overseas

 

[TractorTech]

Hopefully this is helpful:

Search for Equipment Publications - Technical Information Store

techpubs.deere.com

 

[oldnslo]

I am not tech savvy enough to add a link but I tried searching for TM1972 download and this is the site that shows $180.

 

[TractorTech]

I believe TM1623 is what you want as it is the repair manual without the diagnostics, about US$260. TM1972 is the diagnostics only manual.