Ford 5000 power steering issue, veers to the right.

[AntiqueIron]

My tractor uses the early style power steering system. I just rebuilt the cylinder, now the system turns to the right without input, not so much that you can’t stop it, but enough that it would be extremely frustrating to operate- you can hold it back without much pressure, but when you let go it veers off hard to the right (cylinder extending)

The valve spool is a new aftermarket, I measured it with calipers and it is no larger in bore than the previous one.

Everything was well oiled on assembly and the valve went in nicely with what I feel is an adequate amount of drag. Certainly not excessive I feel. I believe I assembled the centering valve stack correctly- washer, spring, washer, seal, back up ring, washer, endpiece.

The book shows an O ring between the valve body and the first washer- I tried it with and without, no difference.



Is there something I’m missing? Do I need to fiddle around with the stop screws a little?

I checked my service manual and troubleshooting says the spool is getting stuck. It sure seems like it shouldn’t be getting stuck to me.

 

[TractorTech]

I would say that your turnbuckle needs to be adjusted. Neutral is pretty finicky to find, but I believe it is adjusted to the extreme so that the centering valve cannot center.

 

[AntiqueIron]

I would say that your turnbuckle needs to be adjusted. Neutral is pretty finicky to find, but I believe it is adjusted to the extreme so that the centering valve cannot center.

Are you referring to the L shaped arm connecting the drag link to the valve’s connecting link?

So basically move the set screws, front screw in rear screw out to “pull” the valve out?

Great suggestion sir- I think you’re on to it. Thank you!

 

[Harry in Ky]

My tractor uses the early style power steering system. I just rebuilt the cylinder, now the system turns to the right without input, not so much that you can’t stop it, but enough that it would be extremely frustrating to operate- you can hold it back without much pressure, but when you let go it veers off hard to the right (cylinder extending)

The valve spool is a new aftermarket, I measured it with calipers and it is no larger in bore than the previous one.

Everything was well oiled on assembly and the valve went in nicely with what I feel is an adequate amount of drag. Certainly not excessive I feel. I believe I assembled the centering valve stack correctly- washer, spring, washer, seal, back up ring, washer, endpiece.

The book shows an O ring between the valve body and the first washer- I tried it with and without, no difference.



Is there something I’m missing? Do I need to fiddle around with the stop screws a little?

I checked my service manual and troubleshooting says the spool is getting stuck. It sure seems like it shouldn’t be getting stuck to me.

The fact you replaced the control valve spool with an aftermarket part raises questions. Why did that need to happen?

While adjustments are always needed (and often critical) you can narrow down the possibilities easily enough. Start by removing one of the clevis pins connecting the final link to the control valve. The valve spool should self center to neutral. Start the engine and see what happens. In theory, the steering should do nothing. If you manually over ride the centering springs with a punch or screwdriver you should be able to actuate steering both left and right by moving the spool in or out. Does that happen?

 

[AntiqueIron]

The fact you replaced the control valve spool with an aftermarket part raises questions. Why did that need to happen?

While adjustments are always needed (and often critical) you can narrow down the possibilities easily enough. Start by removing one of the clevis pins connecting the final link to the control valve. The valve spool should self center to neutral. Start the engine and see what happens. In theory, the steering should do nothing. If you manually over ride the centering springs with a punch or screwdriver you should be able to actuate steering both left and right by moving the spool in or out. Does that happen?

Good point, forgot to mention why- my apologies. The original valve spool had some scarring on its surface from age- nothing horrific but enough that I felt a replacement was necessary. I had to go aftermarket because NH doesn’t sell it. I bought it off Ebay through a company called Cross Creek Tractor. The part was made by titan hydraulics and said made in USA. Part number C5NN3N489B. It looked and measured identical- the end where the valve is capped had an open threaded hole that I plugged with a set screw, but I don’t feel that caused any issues. I’ll pull a pin tomorrow as you suggested and try again.

 

[AntiqueIron]

Ok, so something occurred to me this morning.

When I installed the valve’s cover plate, there was no “tension” from the spring.

What I’m wondering is if perhaps the centering spring was over compressed during rebuild and it being too short is allowing bypass. I think if I back off the threaded clevis end 1 turn or so, it should actuate properly. Easy enough to test I suppose.

Man am I glad I can work on the valve while it’s in the tractor… lol

 

[AntiqueIron]

Ok, so I think I got it.

Moral of the story-

They don’t tell you to do this in the book- but when you take apart the valve (if you have to, I’d avoid it if possible) take some calipers and measure the spring’s compressed length. Duplicate this EXACTLY when rebuilding it.

Now I just need to adjust my stop screws and I can put everything back together!

 

[AntiqueIron]

Hmmm… so it seems now it doesn’t surge but it turns hard to the right, no power steering in that direction, left works fine, acts like a little air in there though but not bad.

Man there’s really very little info out there about this system. The manual doesn’t really tell you much about it at all and NH’s parts diagrams are wonky. I love my tractor but if I were a rich man an aftermarket 70-75 column would replace this annoying system once and for all.

 

[Harry in Ky]

If it fails to steer in only one direction, you probably need to revisit the adjustment with two set screws. If there is enough play in all the pins, bushings, links, ETC (and there always is) it will bottom on one set screw or the other before the control valve spool actually moves. If you open up that adjustment you will have more free play in the steering wheel, but it will probably steer both ways. When they get that way they can be a little wild on the road but work okay in the field.

And yes, there are reasons why Ford eventually got away from that system.

 

[AntiqueIron]

If it fails to steer in only one direction, you probably need to revisit the adjustment with two set screws. If there is enough play in all the pins, bushings, links, ETC (and there always is) it will bottom on one set screw or the other before the control valve spool actually moves. If you open up that adjustment you will have more free play in the steering wheel, but it will probably steer both ways. When they get that way they can be a little wild on the road but work okay in the field.

And yes, there are reasons why Ford eventually got away from that system.

Yes, I believe the screws were out of adjustment. I got my valve travel set finally. 46 thou right hand turn, 45 left hand. Originally it was low 20s, book says 30 to 60. Seems to have equal force now- not much there but I think jacking up the front end and bleeding it off is gonna help. The loader is on jackstands right now so I can’t lift the tractor, and I’ve been only running the tractor 30 seconds at a time because there’s no cooling system currently.

I think it’s just air because when I shut the tractor off I hear a “boiling” sound from the power steering reservoir, which to me indicates air escaping.

Fortunately the pins were all tight- the three small ones had no play in the castings, the cylinder bushing was ok and in round, there was some wear on the tapered anchor pin but honestly I felt it acceptable- maybe .025” at the most.

I will say- I think the later ford systems were phenomenal. This one has its shortcomings but it isn’t horrible. I dislike pure hydrostatic systems because there is no reserve steering mechanism if you blow a hose or something- the tractor is immobilized, basically. I had to steer a 6400 JD in that fashion- in tank fuel pump went out at 7:30 PM on a county road in January, so it had to be towed back and steered using the toe brakes. Puckered me up on corners for certain!