MF135 PS Pump Install Problem

nrowles

Member
Put a new power steering pump on my 135. It's the type that forced fluid thought the gearbox, not true power steering. After I filled the reservoir and turned the wheel back and forth while filling to make sure fluid was through all the lines, the steering got progressively stiffer as I went along. Pump reservoir is completely full and the steering wheel is so stiff I can barely turn the wheel. The further I turn it jumps back and makes a noise in the gearbox. Ouch! What could be going on here? I thought maybe air but it should have worked itself out since I had the reservoir cap off.
 
I forgot to mention that the power steering did work but was leaking badly. That's why I replaced it.

I fear something may have gone bad in the gearbox. I drained all the fluid out of the pump to see what that would do. I can move the wheel freely to the right but once get to center point when coming back left it binds up right there and I can't go any further. Something in the steering gearbox seems to be binding up.

Any thoughts or suggestions?

Do you think a possibly higher pressure with the new pump caused this?
 
1: You have the power steering that has the cylinder bolted to the steering gear box, you resealed it, and it was still working with the old ps pump after you resealed it?
2: The new ps pump made it hard to turn.
3: Did you do any work to the control valve that is on the steering column?
4: You didn't cross the ps pump lines, or any others?

Trying to narrow things down.
 
(quoted from post at 18:51:41 07/10/17) 1: You have the power steering that has the cylinder bolted to the steering gear box, you resealed it, and it was still working with the old ps pump after you resealed it?
2: The new ps pump made it hard to turn.
3: Did you do any work to the control valve that is on the steering column?
4: You didn't cross the ps pump lines, or any others?

Trying to narrow things down.

1: I didn't do anything to the gear box. I simply removed the old pump and put the new one on. The old pump worked immediately before removing it.
2: As I first started adding fluid to the new pump the power steering was working but the more I added as it was working completely through the lines and filling up, the harder it got to turn and it was jumpy and when it would jump it would make a noise in the gear box. I removed the fluid from the pump to see how it would work manually and it is still binding up. It works freely to the right but binds up when trying to turn left. I lifted the front end off the ground so there was no friction when trying to do this.
3: no.
4: Fairly certain I didn't. The lines are bent in such a way it would have been very awkward to try and connect them the other way around.
 
With the front end off the ground, and the engine off I'd loosen all the lines in the power steering system, the four fittings at the steering column are probably the easiest to get loose, and let it bleed the fluid out. When loosening the lines I always assume that they still may have pressure in them (you never know). Once they are loose, try turning the steering wheel both ways, and see if it starts to work easier, and or be able to turn left once all the fluid works its way out the system (going to be a bit messy). The control valve in the steering column seems to be the problem most of the time, but lets see what it after you loosen the lines, and let it bleed out.
 
(quoted from post at 22:00:35 07/10/17) With the front end off the ground, and the engine off I'd loosen all the lines in the power steering system, the four fittings at the steering column are probably the easiest to get loose, and let it bleed the fluid out. When loosening the lines I always assume that they still may have pressure in them (you never know). Once they are loose, try turning the steering wheel both ways, and see if it starts to work easier, and or be able to turn left once all the fluid works its way out the system (going to be a bit messy). The control valve in the steering column seems to be the problem most of the time, but lets see what it after you loosen the lines, and let it bleed out.

Just to clarify. Also, I can look in my shop manual when I get home to see if it has this procedure detailed.

You want me to loosen (not remove) ends of the two power steering lines connected to the cylinder assembly and the valve assembly. These would be lines 68 and 69 in the AGCO parts schematic. I can also loosen lines connected to pump and steering column. So it would be 8 fittings total. Or don't I need to loosen all of them?

I am actually draining the fluid out of the system, not trying to bleed air out of the system while keeping fluid? This should release any locked air/pressure and the wheel should hopefully move freely.
 
Just to drain all the fluid out (no air bleeding) you only need to loosen one end of each line (don't need to loosen both ends). With the system drained see if it's easier to turn, or if it can turn left again.
 
(quoted from post at 09:08:10 07/11/17) Just to drain all the fluid out (no air bleeding) you only need to loosen one end of each line (don't need to loosen both ends). With the system drained see if it's easier to turn, or if it can turn left again.

I loosened some lines and the steering is working now after some fluid drained out. I haven't tightened anything back up yet. Do you think I should tighten everything back up and follow procedure to fill the system with fluid, or do you think I have a problem, or is there something else I should do first?
 
(quoted from post at 16:07:59 07/11/17) I loosened some lines and the steering is working now after some fluid drained out. I haven't tightened anything back up yet. Do you think I should tighten everything back up and follow procedure to fill the system with fluid, or do you think I have a problem, or is there something else I should do first?


I think you probably have a problem with the control valve on the steering column that directs the fluid where to go. The control valve is usually the main problem in a ps system. You could try refilling the system, but I think you will have the same problem.
 
(quoted from post at 18:47:36 07/11/17)
(quoted from post at 16:07:59 07/11/17) I loosened some lines and the steering is working now after some fluid drained out. I haven't tightened anything back up yet. Do you think I should tighten everything back up and follow procedure to fill the system with fluid, or do you think I have a problem, or is there something else I should do first?


I think you probably have a problem with the control valve on the steering column that directs the fluid where to go. The control valve is usually the main problem in a ps system. You could try refilling the system, but I think you will have the same problem.

Any thoughts as to why this problem occurred at the exact moment I swapped pumps? The previous pump did work it just leaked.
 
So are you referring to part 22 in the AGCO parts book being the problem? If I can find a repair kit should that fix the problem?
 
From the research I've done over the past hour I would say if the control valve is the problem I will just remove the power steering. Expensive to fix, may not work, and I don't want to dig in too deep and open any more cans of worms.

I will try one more time to fill the system and see what happens. If it doesn't work properly again, are there any adjustments that can be made that could allow it to work properly? Seems like there are a bunch of different adjustments in the steering so I'm a bit confused.

I'm good at working on things when I know what to do but I have a hard time knowing exactly what to do.
 
Power steering fixes aren't cheap, and the control valve on your tractor probably has never been worked on, and its at least 40 years old. The higher pressure a new pump puts out compared to the pressure of a old, wore out pump will usually find the next "weak spot" in the system. You can replace the valve, or get a repair kit to fix the old one, but chances are you will have to re-seal the power steering cylinder next. The steering setup on the 135's is the only bad thing about them.
 
(quoted from post at 07:45:51 07/12/17) Power steering fixes aren't cheap, and the control valve on your tractor probably has never been worked on, and its at least 40 years old. The higher pressure a new pump puts out compared to the pressure of a old, wore out pump will usually find the next "weak spot" in the system. You can replace the valve, or get a repair kit to fix the old one, but chances are you will have to re-seal the power steering cylinder next. The steering setup on the 135's is the only bad thing about them.

Well that sucks. Guess I should have just let it be and keep adding fluid (was not leaking into crankcase).

If I do away with the power steering how do you suggest I do it? Should I remove anything or just let the system sit empty? I may just put the old one back on and try to sell the new one. Nothing wrong with it.
 
(quoted from post at 10:15:25 07/12/17) Where was the old ps pump leaking at?

My pump appears to be either 193207M91 or 193208M1.

It appeared to be leaking right at the pump. Crankcase levels were not rising and it wasn't leaking from a hose or at the steering gearbox. There was always oil on the underside of the pump. I bought a pump rebuild kit #1810529M91 but that was completely different than the inside of my pump. I cannot locate any of the gaskets and seals my pump requires to rebuild. When trying to take out the seal where pump mounts to tractor I got into the pump itself a little bit scarring the surface and said the heck with it and bought a new one. I'm not sure I could get the old pump in working condition even if I could find the seals. I have everything in pieces in a box. When I said about putting it back on I was thinking more along the lines of just the shell with no oil so everything was still connected and I could try to sell the new one or find somebody that could use it.
 
You could put the old pump back together with the old parts, and put a new AGCO part number 359117X1, or Case/New Holland part number 86012300 (5-5/8" I.D. X 1/8" o-ring). That o-ring goes between the pump housing, and the reservoir, and it will usually seal it unless the reservoir housing is deformed. That may make your power steering work again to some degree without it leaking.
 
(quoted from post at 11:18:46 07/12/17) You could put the old pump back together with the old parts, and put a new AGCO part number 359117X1, or Case/New Holland part number 86012300 (5-5/8" I.D. X 1/8" o-ring). That o-ring goes between the pump housing, and the reservoir, and it will usually seal it unless the reservoir housing is deformed. That may make your power steering work again to some degree without it leaking.

I can't get pictures in AGCO to print to pdf. Says they are encrypted or something.

That O Ring is part of the kit I already have. My problem is that when I was tearing apart to put the new kit (wrong one) in, I destroyed parts #11 Oil Seal, #23 Gasket Diaphragm Back-Up, #24 Protector Gasket, #25 Diaphram Front Plate and Gear. Also, #29 and #31 snap rings didn't appear to be in the pump. I thought all of these seals and gaskets were part of the kit I was buying.
 
Well I filled it with fluid again tonight and got different but still unsatisfactory results. After filling, with the wheels in the air the steering worked. Yay! I of course can't tell if the power steering is doing anything because there isn't any resistance. I put the wheels down and tried to move the tractor and the wheels won't budge in EITHER direction, so with oil in the system I can't even steer manually when the wheels are down. Whenever I try to turn you can hear a load on the engine. Also, the rpms would change without touching the throttle or moving the steering wheel. Almost like the gear in the pump was putting a load on the engine. ???

So with oil in and the wheels in the air the wheels turn. When wheels down they won't turn in either direction and there is a load on the engine.

Is it possible it is a faulty pump? Or do you still think control valve? I hate to turn the pump back in for warranty if that's not it.
 
(quoted from post at 16:22:20 07/12/17) Well I filled it with fluid again tonight and got different but still unsatisfactory results. After filling, with the wheels in the air the steering worked. Yay! I of course can't tell if the power steering is doing anything because there isn't any resistance. I put the wheels down and tried to move the tractor and the wheels won't budge in EITHER direction, so with oil in the system I can't even steer manually when the wheels are down. Whenever I try to turn you can hear a load on the engine. Also, the rpms would change without touching the throttle or moving the steering wheel. Almost like the gear in the pump was putting a load on the engine. ???

So with oil in and the wheels in the air the wheels turn. When wheels down they won't turn in either direction and there is a load on the engine.

Is it possible it is a faulty pump? Or do you still think control valve? I hate to turn the pump back in for warranty if that's not it.

I'm about equal to you when it comes to the power steering problem knowledge. But taking just a guess, it kind of sounds like it's trying to turn both ways at the same time. Hence the stuck wheel.

Maybe some of the knowledgeable guys can expound on this.
 
It is possible the new ps pump is bad, seen it before on remanufactured ps pumps for cars, and trucks. Even had other "brand new" parts that were bad right out of the box.
 
(quoted from post at 16:22:20 07/12/17) Well I filled it with fluid again tonight and got different but still unsatisfactory results. After filling, with the wheels in the air the steering worked. Yay! I of course can't tell if the power steering is doing anything because there isn't any resistance. I put the wheels down and tried to move the tractor and the wheels won't budge in EITHER direction, so with oil in the system I can't even steer manually when the wheels are down. Whenever I try to turn you can hear a load on the engine. Also, the rpms would change without touching the throttle or moving the steering wheel. Almost like the gear in the pump was putting a load on the engine. ???

So with oil in and the wheels in the air the wheels turn. When wheels down they won't turn in either direction and there is a load on the engine.

Is it possible it is a faulty pump? Or do you still think control valve? I hate to turn the pump back in for warranty if that's not it.

Don't give up yet. The system in principle is very simple, there is only the pump, control valve and the steering cylinder actuated by the said valve.

There is a certain amount of free play in the mechanism before mechanical torque from the steering wheel is applied to the front wheels. The actuator to the control valve is connected to the rod from the steering wheel without play(or should be, this is likely the most common problem on these, play on the control valve actuator), so when you turn the wheel the valve actuates first and it assists in the steering without the user having to transfer mechanical power to the wheels. If the power steering is not working, then the mechanical actuation takes over after a bit of free play on the wheel.

With this in mind and going back to the results after your last attempts, I'm thinking of a few points

1) Pump is loading the engine, as the revs are going down. This points to the fact that the pump is good, and could be verified by cracking the pressure hose on the pump and seeing if you get oil out.

2) With the wheels in the air I suspect the valve is not actually actuating at all

3) With the wheels down they don't turn freely anymore, and you're actually actuating the control valve now. But, instead of steering now it is locked up. A couple of scenarios come to my mind. If by some reason the lines were crossed, the steering would actually shoot to the opposite direction. But since it's being locked up, I think the problem must be in the control valve either not providing fluid to the steering cylinder, or not letting the fluid out.

I think I would next crack open the lines going to the cylinder, and see if you're actually getting hydraulic fluid where you want it. If not, work on the control valve next.
 
(quoted from post at 02:31:23 07/13/17)
(quoted from post at 16:22:20 07/12/17) Well I filled it with fluid again tonight and got different but still unsatisfactory results. After filling, with the wheels in the air the steering worked. Yay! I of course can't tell if the power steering is doing anything because there isn't any resistance. I put the wheels down and tried to move the tractor and the wheels won't budge in EITHER direction, so with oil in the system I can't even steer manually when the wheels are down. Whenever I try to turn you can hear a load on the engine. Also, the rpms would change without touching the throttle or moving the steering wheel. Almost like the gear in the pump was putting a load on the engine. ???

So with oil in and the wheels in the air the wheels turn. When wheels down they won't turn in either direction and there is a load on the engine.

Is it possible it is a faulty pump? Or do you still think control valve? I hate to turn the pump back in for warranty if that's not it.

Don't give up yet. The system in principle is very simple, there is only the pump, control valve and the steering cylinder actuated by the said valve.

There is a certain amount of free play in the mechanism before mechanical torque from the steering wheel is applied to the front wheels. The actuator to the control valve is connected to the rod from the steering wheel without play(or should be, this is likely the most common problem on these, play on the control valve actuator), so when you turn the wheel the valve actuates first and it assists in the steering without the user having to transfer mechanical power to the wheels. If the power steering is not working, then the mechanical actuation takes over after a bit of free play on the wheel.

With this in mind and going back to the results after your last attempts, I'm thinking of a few points

1) Pump is loading the engine, as the revs are going down. This points to the fact that the pump is good, and could be verified by cracking the pressure hose on the pump and seeing if you get oil out.

2) With the wheels in the air I suspect the valve is not actually actuating at all

3) With the wheels down they don't turn freely anymore, and you're actually actuating the control valve now. But, instead of steering now it is locked up. A couple of scenarios come to my mind. If by some reason the lines were crossed, the steering would actually shoot to the opposite direction. But since it's being locked up, I think the problem must be in the control valve either not providing fluid to the steering cylinder, or not letting the fluid out.

I think I would next crack open the lines going to the cylinder, and see if you're actually getting hydraulic fluid where you want it. If not, work on the control valve next.

I will run these tests but it sounds like you are leaning towards valve just as ptfarmer is. I assume the pressure line you speak of would be the bottom one on the pump?

One thing I'd like to note that I forgot to mention was that while having things apart I also put oil in the gearbox after attempt #1, which it took quite a bit. Not sure how much was in before I filled. Wonder if this had anything to do with wheels turning (while in air) on attempt #2.
 
Any kind of oil, or grease you put in the steering box where the sector gears are shouldn't effect the ps system as that part is sealed off from the hydraulic section of the steering.
 
I know I've beat this thing to death but I have one more question before I cut my losses and go to manual steering.

I went out today to remove the ps fluid and go to manual steering. Figured I would try driving it one more time. I got the wheels to turn while moving (they were locked tight when I parked it) but they were very hard to turn. Just as I was ready to park the tractor I saw smoke. It was blowing fluid out the pressure relief on top of the pump.

So changes since last post are that I can move the wheel but it's very tough and oil is spewing out the pump pressure relief valve. No fluid coming out anywhere else.

Seems like that would confirm the control valve, correct?
 

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