MF 135 Power steering issues

[goeduck]

On my MF245 when topping off my power steering fluid, I put the front on blocks and turn the wheels back and forth a number of times with the cap off to get all the bubbles out. When in one direction or the other (can't recall which) the system holds more fluid. So I top it off on the higher fluid direction and then put the cap on. I don't know if your MF135 is set up the same.

This link says to top off with wheels centered.

MF 245 Power Steering Issue

Hello all! I recently bought a 245 MF, Serial # 9A250460. I bought the tractor with the orbital gear already off, because it was leaking. I ordered the parts and fixed the leaking problem. But, I am having a heck of a time bleeding the air out of the system. I finally got it bled and drove it...

www.tractorforum.com

 

[FordnMassey]

No, a small air leak on the inlet side of your pump would always be under suction (negative pressure) when running and no pressure when not running so you'd probably not see any fluid leakage. Besides, the air leaks, if they are there, are probably very tiny and not easy to find or see. Could have been that way for a while and just got worse wiggling things around during the incident.

Jwr has nailed it. The air leaks inward on the suction side. For a seal to fail in this way is very different from a seal leaking a fluid out, so it's pretty easy event for there to be no oil leaking out while air gets in.

Additionally, the seal that fails is on the input drive shaft of the power steering pump. The drive for the pump is likely a gear on the pump shaft that meshes with a gear inside your engine. This set up usually allows oil leaks from the seal to go to the engine sump where you can't see it.

The key idea here is air leaking inward due on the suction side of the pump. We almost always deal with fluid leaking out, so it's a bit of a shift in thinking to get a handle on.
If you have foaming oil that keeps recurring, you have air leaking inward on the suction side.

Mine was a Ford 3000, 1967, external cylinder, remote reservoir type power steering. May have been sucking air for a while, and finally got bad enough to overfill the reservoir. I took the bonnet off and the jet if foamed oil spraying was something to see! It only becomes a noticeable problem when the oil can't lose the bubbles faster than they're created. So may have been there for a while before I knew about it.

My pump was rebuilt in around 4 hours, half being cleanup and removal. It was not complicated..... I'm not a mechanic and I did it easily.

 

[jticknor]

Stupid question: the service manual says to keep bleed it until you can leave the plug out of the reservoir and the fluid stays calm. Even when turning the steering wheel and while it's running? When I try that the fluid goes everywhere....

 

[jticknor]

Jwr has nailed it. The air leaks inward on the suction side. For a seal to fail in this way is very different from a seal leaking a fluid out, so it's pretty easy event for there to be no oil leaking out while air gets in.

Additionally, the seal that fails is on the input drive shaft of the power steering pump. The drive for the pump is likely a gear on the pump shaft that meshes with a gear inside your engine. This set up usually allows oil leaks from the seal to go to the engine sump where you can't see it.

The key idea here is air leaking inward due on the suction side of the pump. We almost always deal with fluid leaking out, so it's a bit of a shift in thinking to get a handle on.
If you have foaming oil that keeps recurring, you have air leaking inward on the suction side.

Mine was a Ford 3000, 1967, external cylinder, remote reservoir type power steering. May have been sucking air for a while, and finally got bad enough to overfill the reservoir. I took the bonnet off and the jet if foamed oil spraying was something to see! It only becomes a noticeable problem when the oil can't lose the bubbles faster than they're created. So may have been there for a while before I knew about it.

My pump was rebuilt in around 4 hours, half being cleanup and removal. It was not complicated..... I'm not a mechanic and I did it easily.

Like which seal are you talking here? Thinking I may just be getting the rebuild kit that comes with all of the seals. You referring to that seal no 9 there on the shaft where its heads into the engine?

 

[jticknor]

I just spent probably 30 minutes with it cranked and the plug out of it turning the steering wheel back-and-forth. Every time I turn all the way to one side and then start to turn back the other I get air coming out. Both directions. And then when I stop and turn it off I get bubbling for a while afterwards. Like pretty decent sized bubbles gurgling out. Seems that would mean either a pretty serious leak or somewhere there was a lot of air in the system? Wondering if maybe the pressures involved in the system busted an already compromised seal? But if it was all going into the engine shouldn’t I see that in the engine oil? That does seem to have made it better. But it’s definitely still not right….

 

[goeduck]

I never considered the design on my MF245 to be ideal but it works good enough.

 

[FordnMassey]

I just spent probably 30 minutes with it cranked and the plug out of it turning the steering wheel back-and-forth. Every time I turn all the way to one side and then start to turn back the other I get air coming out. Both directions. And then when I stop and turn it off I get bubbling for a while afterwards. Like pretty decent sized bubbles gurgling out. Seems that would mean either a pretty serious leak or somewhere there was a lot of air in the system? Wondering if maybe the pressures involved in the system busted an already compromised seal? But if it was all going into the engine shouldn’t I see that in the engine oil? That does seem to have made it better. But it’s definitely still not right….

Hi,

Yes, if no9 is a seal, that's what I reckon is the trouble.

Regards the leaking into your sump, it's unlikely that oil gets out, but if it did you won't see it. I'm suggesting this is a leak allowing air in. That's why you can't purge the system no matter how much you try.

I would recommend a full seal kit. If one seal has failed, other seals/O rings will fail soon.

 

[jticknor]

Thanks. I’ll give that a try and see what happens.

 

[jticknor]

I've rebuilt the pump. A question. Theres a relief valve that I had to (or at least thought I had to) remove in order to get it apart and replace the seal. Seal went in ok, old seal did seem pretty worn out.

This relief valve, the service manual says to adjust it to 1500 psi. Any thoughts on how to make sure it's right? The only way I know is put the pump on, crank it up with a gauge hooked up between the pressure line and the pump and if its not right take the whole thing apart and try again? Wish I'd marked where the damn thing was at before i took it apart. Rookie move....

 

[FordnMassey]

Hi,
Yep, that's unfortunate. I don't know the set up of the relief valve as I avoided dealing with it on mine. So I can't offer a better idea than yours. Wait to see if anyone else has a good idea.