Question on 4630 power steering

[NoDakInMN]

So, I have been fighting the return line from the power steering valve leaking and/or blowing off at the valve. Initially I thought the issue was due to an old hose, so I got a replacement from Mother Deere, and that blew off as well. But it did seem that the replacement fit rather loosely on the fitting, so I took a 3/8" barb end union and spliced in short piece of 3/8" hydraulic hose and that fit a lot tighter on the valve connection. And some people told me that the return line may be over pressurizing, and that did make some sense, but at the time I felt that the JD hose fit so loosely that it was possible that a few psi could cause it to blow off.

So, the last fix seemed to cure the problem, for a while, but it blew off again and now I agree that there is something pressurizing the return line. Up to this point I assumed that it was an issue in the steering valve that was at fault, as that seemed to be the obvious place and I did have to replace the seal in the steering column not too long ago. But the thing that has me questioning this a little bit, is that when it blew this time, instead of shutting down the tractor instantly, as I had previously, I needed to get the tractor moved the 20' so that it wasn't blocking the door to my shop. I also had not replaced any of the panels I had removed to reconnect the hose, so I was able to observe that most of the oil was coming out of the hose and not the valve.

So, is it possible that there is something building a back pressure on the return line causing the issue, or is it that I need to rebuild the steering valve? If it is the steering valve, I would appreciate and tips or hints on the best way to go about it.

Thanks in advance for any replies.

This post was edited by NoDakInMN on 12/05/2023 at 02:01 pm.

 

[tim s]

for one thing those hoses had always given problems Deere converted them to JIC fittings and hoses later on,, You should do that,, also there is a check valve in the metering pump that for some reason jams up,, this let charge oil into the metering pump. That fitting is pricey, but it is one of the fittings that you replace for the upgrade,, I have a parts list here some where of all that you need to upgrade,, I will trey to find it and post it after bit.

 

[NoDakInMN]

Thanks Tim.

 

[rdhRDH]

as Tim S. said 9 times out of 10 it is the check valve, fix it as soon as possible because if it blows off below the cab and you do not notice in time it will rob transmission of oil and seize up gears, did several back in the day

 

[NoDakInMN]

It is parked for now until I can get it fixed.

So where is this check valve located?

 

[Cliff Nelson]

Just to add, the return hose goes to the charge line going to the main hyd. pump therefore it has some back pressure on the hose.