4230 steering valve

[jonesrj]

We have a late model 4230 with excessive fluid
leaking through the steering valve. We had the
same thing happen on a 4240 some years ago and
have the valve that came off that tractor. When
we inspected the old 4240 valve, the body and
piston shows significant scarring on both parts.

Does anybody have experience rebuilding these
valves? Anything we can do to keep from spending
the $1100+ that JD wants for a new one?

When you look at the service manual and flow
diagram it appears that there is a location along
the piston that you could put an o-ring and backup
washer to keep the high pressure oil separate from
the control oil.

Another alternative we thought of was boring the
housing to some 0.030 or 0.050 inches larger and
rebuilding the piston to fit...but I'm not sure if
that saves much $$ and how reliable it would be.

I know there are some pretty slick fellas on here
with all sorts of hydraulic experience on these JD
tractors, any help would be most appreciated.

Thanks.

 

[tim s]

They are not made to rebuild, the spool valve is honed to fit the body,,and they are over priced that's for sure. We had a 8640 that was leaking through, but it only showed up when it was setting idling, it would hinge tight one way,,had to make sure you shut it down when you were fueling out of the pick up,, the ones for the big 4'wheelers are very high priced. I would check with a salvage yard first.

 

[jonesrj]

I was hoping to hear from you on this Tim. You built a 4020 hydraulic pump for my uncle a month or two ago (we're in north Alabama, if you happen to remember him). I thought you might have some experience with these 30+ series steering valves, etc.

What about the check valve in the metering pump? Does that fitting act as an orifice to limit flow through the steering valve and meter pump or is it a true check valve to prevent backflow of oil?

I actually tried putting the oring and backup washer on the piston in the valve, but I think I cut the oring during assembly as it seemed like it may help when we first cranked the tractor, but then went to leaking soon after.

I saw some used valves on the web for sale but after having two of these go bad, I was a bit leery of spending $600-800 on a used one and having no idea about its condition...

Thank you.

 

[tim s]

Ooh yes I remember your Uncle, a real nice
Gentleman..I don't have that much trouble with the
valve, and I refer to them as the "Steering
Brick", mounted out under the hood, "not" the
pump/valve at the base of the steering column,,the
one at the base of the column give the most
trouble around here, and there are a couple
different things that cause that, one is the
thrust bearing at the top of the column lets the
shaft work up out of the seal area, and the other
is the check valve letting oil back into the
metering pump, also if you can do it while working
on the metering pump is to replace those darn push
on fittings with JIC type fittings from the later
40 series valve, it will eliminate a lot of
leakage under the dash.

 

[jonesrj]

Good deal, thanks Tim.