Massey Ferguson 65 gas, power steering issue

[David Stobbe]

Hi everyone, this is my first post to this forum, I'm looking forward to picking some brains that have more experience than I do.

I bought this tractor last fall, only to find that it had a major power steering issue. It had had a broken power steering cylinder bracket, a cast bracket which the previous owner had repaired. During unloading, the pitman arm pinch bolt was loose, which caused the steering arm to drop and jam against something immovable. I left the tractor where it was until I could reposition the pitman arm and tighten the pinch bolt. When I did so, I also discovered a major leak from the power steering pump.

I also discovered when I tried to move the tractor, that it had no power steering function, even with the pump refilled. Somewhere around this time I removed the front cover from the tractor and discovered that the cylinder bracket was broken again. As I couldn't find one readily available, I took it to a local welding shop that actually understood cast iron and repaired it properly. I also purchased and installed a new power steering pump.

Fast forward to today. After numerous attempts to bleed the power steering system, I have no discernible boost. I jacked the front end and turned the wheel lock to lock numerous times, and the fluid level moved up and down and had the appearance of being pumped. There didn't seem to be much air, if any.
Unfortunately, with the wheels back on the ground I don't think I have any boost at all in either direction.

At first I thought I had some boost to the left, and adjusted the turnbuckle on top of the cylinder as per instructions to encourage right boost, but with no discernible effect. Now the steering seems equally difficult in both directions.
The turnbuckle pins are slightly worn, allowing some slack, and I have not yet replaced them.

Sorry for the long post, any thoughts?

David

 

[Eric in IL]

A very snug fit of the pins at each end of the turnbuckle is highly important.

 

[miangus]

Make sure someone has not tightened the alignment bolt all the way down. The way to get a starting point is to loosen the jam nut on the tapered alignment bolt. Tighten the bolt to center the steering. Adjust the turnbuckle so it is centered, replace any worn pins. Then back the alignment bolt back out until there is enough movement in the steering to operate the steering valve. I have always found the system to be self-bleeding. The lines from the pump also must be installed correctly.

 

[David Stobbe]

(quoted from post at 08:46:31 04/17/23) Make sure someone has not tightened the alignment bolt all the way down. The way to get a starting point is to loosen the jam nut on the tapered alignment bolt. Tighten the bolt to center the steering. Adjust the turnbuckle so it is centered, replace any worn pins. Then back the alignment bolt back out until there is enough movement in the steering to operate the steering valve. I have always found the system to be self-bleeding. The lines from the pump also must be installed correctly.

******

I'm finally getting back to this.
I've replaced the pins, which had zero effect.
There doesn't seem to be any air in the power steering system.

I've arrived at the conclusion, rightly or wrongly, that the power steering fluid is circulating in a bypass, thereby generating no boost. The fluid is clearly moving when the PS pump cover is removed, but I have absolutely no boost in either direction.

Can anyone tell me where the by-pass valve is located in this system? If its in the pump, then my new pump may be flawed. If it's in the valve assembly then I will look closer at that. I cannot tell from the factory manual where such a by-pass situation might originate.

I also checked the alignment bolt, and it is fine.
The turnbuckle is centered and the PS lines are installed correctly.

Thanks for your help.

David

This post was edited by David Stobbe on 06/19/2023 at 10:52 am.