JD 4040 Looses steering

[trouble007]

we have a JD 4040 that once warmed up looses the power steering. we have changed the filter and the oil with no change and have also checked to see if the rad is plugged and its not. the block above the right hand remote when looking at the back gets hot to the touch when running. the pump was rebuilt last fall so i dont think that that is the problem any ideas?

thanks

Ryan

 

[kennyd]

Welcome to TBN

First, you need to change that avatar, I have a copyright on it:laughing:

I suspect it may be the orbital valve that's connected to the steering wheel, or the steering motor. I just looked in jdparts and that machine sure has a complicated setup! Hopefully user JD110 can help.

 

[JD755]

I thought at first kenny had bought a 4040.

 

[trouble007]

Welcome to TBN

First, you need to change that avatar, I have a copyright on it:laughing:

I suspect it may be the orbital valve that's connected to the steering wheel, or the steering motor. I just looked in jdparts and that machine sure has a complicated setup! Hopefully user JD110 can help.

would that cause the heat too? and i will get right on the other avatar i have another better picture in the works

 

[kennyd]

You first need to define "heat". Hydraulic oil gets hot, not uncommon for it to get 100* over ambient temps when the machine is working. 120* can feel "hot to the touch". But in general, a valve that is bypassing some oil through a PRV (pressure releif valve) can get very hot quickly.

PM user jd110 and point him to this thread-I bet he will have some specific info for you.

New avatar looks nice:thumbsup:

 

[jenkinsph]

First thing I would do is a system pressure test using a good hydraulic oil guage rated for about 5000 psi. You need to know what the specs call for to see if you are in the correct parameters. Don't know the settings for the 4040 but for the earlier 4020 it is 2200 psi.

As far as filters are concerned there is an additional inlet screen on the hydraulic pump about the size of a 410 guage shotgun shell. I have seen people replace the hydraulic filter and fluid yet miss this inlet screen. Just something I would check out. This can starve the pump causing a loss of pressure and therefore keep the pump constantly instroke which leads to high temperatures.

Last fall we had a piston in the hydraulic pump fail on a similar tractor as yours (2840/3130) and had high enough pressure develop to crack the power steering valve housing. All of this said I would not assume the pump is fine just because it was replaced.

 

[trouble007]

thanks i will check the inlet filter where would be a good place to check the pressure of the system right on the pump outlet?

thnaks
Ryan

 

[jenkinsph]

I would use a quick coupler male adaptor with bushing and guage plugged into a rear outlet. Operate the coresponding rear valve and read the pressure deadheaded. I wouldn't stand in the way of it while testing though. You may have to try the remote valve in both directions to get the reading. I would be expecting somewhere around 2200-2500 psi, really best is to know what the system pressure is spec'd out to be. It has been 25 years since I had a 4020 but as I recall the pump pressure is adjusted on the bottom of the pump in the front and is next to the inlet tubing ( with the aforementioned screen). I wouldn't start tweaking it yet, just thought I would mention where it is.

 

[trouble007]

ok thanks i have a gauge i just need to see if i have the right fittings to connect it.

thanks

Ryan

 

[jenkinsph]

Make sure the bushing is rated for hydraulic system pressures. Meanwhile I am doing a little research on your tractor.