Anyone know anything about power steering on a backhoe?

I have a IH-3400A backhoe in decent condition but the power steering
has gone out. It started failing by working intermittently and now,
it is completely gone. Yes, it has fluid. Sometimes the steering
wheel will turn if you put a great about of force on it and the front
tires will turn. At other times, the steering wheel will easily turn
but not front wheel action.
I do have a limited service manual for the machine showing the flow
for the steering. I was thinking of getting a 0 to 4500 p.s.i. gauge
and working down the line to see where I am not getting pressure but I
don't know what I am doing.
Any ideas that don't cost an arm and a leg?
Thanks
Joe
Reply to
justme
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I presume this is full hydraulic steering i.e. no mechanical linkage, just a pair of hydraulic cylinders or a double ended cylinder operating the wheel linkage? There is essentially nothing that can go wrong on that end beyond a leaking or crushed cylinder.
Attached to the steering wheel will be a hydraulic steering valve unit with four hydraulic connections, two to the steering cylinder(s), a hydraulic pressure supply and a return to the hydraulic tank. You can check for hydraulic pressure at the input, but 95% chance it's fine if the rest of the hydraulics on the machine are fine since they are normally all fed from the same pump.
These steering valves are rather complex, but they aren't all that expensive, especially if they are newer. You may be able to buy a rebuild kit for the steering valve for $30-$50. Northern Tool and Surplus Center both list some hydraulic steering valves for around $450-$500.
Reply to
Pete C.
About the only thing I can say for sure is that, at least on cars, the power part is only "power assist" - it's fail-safe, in that if the pump goes out, you can still steer the car by way of the mechanical linkage, if you're stronger than Aunt Tillie. ;-)
I'd look into that first - Pitman arm, idler arm, drag link, tie rods, that sort of thing, before I'd start troubleshooting the hydraulics.
If it's entirely "steer-by-wire", so to speak, then, yeah, your plan is what I'd probably do. Intermittent pump, worn spool valve(s), leaky cylinder(s) and so on.
Has it recently had any trauma where you could have a bent component?
Good Luck! Rich
Reply to
Rich Grise
Thanks allot, Pete.
No leaks or crushed cylinder. I will give it a better inspection.
Pretty sure that it is a dual-action cylinder.
Joe
Reply to
justme
Lift the front wheels off the ground and run it back and forth about fifty times. Does it ever kink? I'm wondering if you're losing balls or worm in your steering gear.
Is it making noise at all? Does the noise change when it binds? Do the pressure lines torque when you force it to the locks?
Broken springs on the pressure regulator can cause this symptom, too, by allowing most of the force to bypass.
-- "A patriot must always be ready to defend his country against his government." --Edward Abbey
Reply to
Larry Jaques
I have almost the same model hoe with a complete set of manuals. Can copy a few pages and email if you need.
You're describing an O ring or backup ring failure in the stearing cylinder. If true, it should go back and forth nicely with front tires off ground. This is an easy repair. If that's not it, crack the hose line on each side of stearing cylinder. Oil should spurt when you try to turn - this is a poor man's pressure check. If you're not getting flow - hire a real mechanic.
If you need more send your email request to karltownsendembarqmail.com
Karl
Reply to
Karl Townsend
Sometimes they use a double action, double rod (for equal displacement push/pull) cylinder, sometimes just two normal cylinders (the Deere 500C I used to have used two). It doesn't really matter since the end result is the same, and in either case there is almost no chance of the problem being there.
The problem is almost certainly in the steering valve, could be a bit of crud that got to it and is sticking a valve, could be a torn / worn seal, whatever.
I overhauled the steering valve on my old 500C with an inexpensive rebuild kit. That was an older style steering valve and while a bit of a pain it wasn't that bad. Your valve may be newer which may make it easier to deal with, or a new valve may be cheap enough to just replace it.
If you can replace the valve at a reasonable cost that will get you running fastest. Also get a rebuild kit and rebuild the old valve at your leisure so you have it as a backup.
Reply to
Pete C.
These are normally 100% "steer by hose" and normally run from the main hydraulic supply so if the rest of the machine is working properly the hydraulic pump is fine. Almost certainly it's an issue with the rather complex hydraulic steering valve.
Reply to
Pete C.
It's a backhoe, it doesn't have steering gear. This is 100% "steer by hose" hydraulic steering. His symptoms of sometimes hard to turn the wheel, sometimes the wheel freewheels point to the hydraulic steering valve.
There is not likely to be a pressure regulator of the type you're thinking of either, this normally runs off the main hydraulic pump and these are normally closed center hydraulics with serious variable displacement pumps.
Reply to
Pete C.
That would fit the "sometimes the steering wheel freewheels", if it uses a single dual rod steering cylinder, however it would not fit at all with the "sometimes the steering wheel is very hard to turn". My bet is on the steering valve.
Reply to
Pete C.
Oh, yeah. I've seen that type. Kinda like a power rack and pinion, without the rack and pinion gear, huh? ;) I've always lived in the automotive repair mindset.
OK, got it. Thanks.
-- "A patriot must always be ready to defend his country against his government." --Edward Abbey
Reply to
Larry Jaques
It sounds just like what happened to my 1963 Fordson Super Major ( Ford 5000 ?? in USA ), steering would fail intermittently and the tractor would veer to the left. Full power steering, not power assisted. No motor running, no steering, steering wheel will just rotate.
#1 son was driving on the road one time when it happened and he ran over a 90 kmh speed limit sign. Turned around and lifted it up again with the FEL.
We replaced the steering actuator to no avail, it was not the problem. The hydraulic cylinder had intermittent weepage from one side to the other, which is why it always turned to the left. A seal kit fixed the problem or take the cylinder to a specialist if not sure you can do it yourself.
That is your first check and should fix the problem.
If you do need a new actuator, email me and I will look up where I got mine from, somewhere in Indiana I think, they were the least expensive worldwide, and excellent service, about Oz $450 delivered, $580 from local ripoff distributor with minimum 3 week delivery, 8 days from USA.
HTH
Alan
Reply to
alan200
An intermittent leak in the cylinder would fit with the "steering wheel sometimes freewheels" symptom, but not the "steering wheel sometimes very hard to turn" symptom.
Reply to
Pete C.
Bad steering control valve.
Reply to
Steve W.
Is it power steering like a car or true hydraulic steering like many tractors?

Reply to
Bob La Londe
Okay, Pete.
I will take some pictures of it and post on here where they are.
I really appreciate everyone's help.
Joe
Reply to
justme
No, Rich, no trauma. It has no rack and pinion.
I will post some pictures.
Thanks for your help
Reply to
justme
Great, Karl. What model do you have?
I have somewhat of a service manual. One section of this manual is GSS -1416 (REV. 3), printed at the bottom left of each page.
I am going to take some pictures and post them on Photobucket and I will post the url here.
Thanks
Joe
Reply to
justme
Good, Alan. I will get some more data and post it.
Thank you.
Joe
Reply to
justme
I think Pete C. is very adamant on that being the problem. I don't look forward to taking that apart.
I appreciate it, Steve.
Joe
Reply to
justme

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