Power Steering Leak

[mtnxtreme]

My power steering leaks on the 2 sector arms shafts on both sides. Is it difficult to replace these seals ? Should the power steering work even though they leak ?

 

[riveroadrat]

You have a failing control valve bottom seal. There's a pressure seal on both sides of the valve. If the bottom seal leaks p/s fluid gets into the
90 w oil gearbox side. If the top seal leaks you start getting it out the top of the tube under your steering wheel. I think Hobo,NC has a good
rebuild post on here with pics somewhere. Search his name on modern view it should pop up.

 

[Hobo,NC]

I have a post on the upper seal I have never been into the control valve but Ultradog MN has : )...

 

[riveroadrat]

I would change the sector seals while doing the control valve. They're pretty hard to get out without removing the sector shafts. You might want to takes pics as you need to put the sector gears back in just like they came out or you will have to re-time them to the steering shaft. And try not to move the steering shaft from its position also. Check the slop in the shafts by wiggling around the sector arms. I would replace the sector shaft bushings if needed while in there. I used a long bolt with a socket or something that just fits inside the bushing hole, can't remember, to pull the old bushings out and pull the new ones in. Put the new ones in your freezer for a while before you are ready to install them. Mine went in a lot easier than I expected. Oh yea, be careful and don't lose any of the small parts in the steering control valve when you remove it. If you have a magnet you can pull some of the small parts out with it. I always cleaned mine and marked them with a felt pen as to which hole and position they came from. Pay attention to which way the big spool in the middle of the valve goes, one end has a groove in it. A manual would be worth the price so you can read up on it before you start.

 

[mtnxtreme]

Does anyone do the rebuild on these ?

 

[Sean in PA]

Is it power steering fluid that is leaking out or gear oil? If it is gear oil then it might just just the sector arm seals, which I believe (but I may be mistaken) can be replaced without tearing into the upper part of the steering column where the control valve lives.

 

[mtnxtreme]

Its hard to tell, I thought it used the same fluid ? The PS tank is empty, and it drips right off the sector nut and shaft, even when just sitting not running. Where do you drain the steering unit from. from ? I was thinking it should be easy to take the sector arm off and change it, or is from inside ?

 

[Sean in PA]

The two oils are different. The lower sector gearbox should have gear oil (80 or 90 weight or 85W-140), or possibly NIGL 00 grease in it. The power steering hydraulics can use any of a number of thinner hydraulic oils. Some folks use the 134D compatible fluids while other use real power steering fluid and others use straight hydraulic fluid. If the fluid coming out of the sector shaft seals is thin and drips steadily then it is most likely the power steering fluid and that means that the lower control valve seal is leaking fluid down into the gearbox and then it is leaking out the sector shaft seals. You will need to replace the control valve seals as well as the sector shaft seals. Check the condition of all of the internal plungers, balls and springs in the control valve while you have it apart and replace any parts that are broken or badly worn.

 

[Ultradog MN]

You may have a couple of issues going on.
They may be related. They may not be.
First, it is very common to see them leak
down the side of the transmission. It may
be black looking 90 wt leaking from the
lower portion of the box. They leak from
the sector shaft seals. Those can easily
be replaced by removing the steering arms
from the sector shafts and replacing them.
Those seals are flimsy things so it is best
to make a driver to tap them in.
You also state that your PS reservoir is
dry. Do Not run it that way! You will
destroy the pump.
Those are very simple systems.
They will often leak in two places.
The seals at the top and bottom of your
hydraulic block go bad.
#s 28 and 44 in the diagram below.
There is a breather on the lower portion of
that system. #30
Sometimes the lower seal will fail and it
will pump ps fluid out of that breather.
So the hapless owner will remove that
breather and replace it with a pipe plug.
What happens it begins to pump the ps fluid
out of the sector seals. PS fluid is nearly
clear (or red) and easily distinguishable
from the black 90W.
The only way to fix it is to renew that
lower seal - #28.
Those ps steering columns are actually
quite simple to over haul.
Once overhauled and resealed they will give
you many years of good service.
Where are you located. If close to the Twin
Cities I could do it for you.
If far from here, shipping - both ways -
would probably make it uneconomical.

 

[mtnxtreme]

Ultradog, I would be willing to ship it to you, I just don't have the time, I could pull it apart though, can you PM me your info, price etc. ? Thanks

 

[Mike(NEOhio)]

I've replaced mine. Not a hard job. The gear box was empty but power worked so I didn't notice for a long time. The replacement felt rings I got were useless.
Originals were about 1/2 inch thick. The supposedly correct replacement were about 1/8. I had some felt so I made my own.

 

[mtnxtreme]

You replaced only the sector seals and it worked ?

 

[mtnxtreme]

So after looking more closely, I'm understanding the upper housing holds all the PS fluid under pressure and the lower housing is filled with grease by a grease fitting, no pressure. So if PS fluid is leaking at the sector arms, the seals between upper and lower housing are shot, so hypothetically I can pull the upper box, change those seals, leave the lower box in place and pull the sector arms off and change the felt and oil seal from the outside, does this make sense ? And when I refill the gear box with grease, what type grease and how do you know its full ?

 

[riveroadrat]

You should read UltradogMn post on the job. someone also said something about not putting grease in the gearbox side because you don't want the
pressure from your leak (which is pretty high) to push grease into your p/s system. Make sure you have a factory steer wheel on it so it keeps rain
out of the top of the column.

 

[mtnxtreme]

(quoted from post at 12:22:46 04/15/21) You should read UltradogMn post on the job. someone also said something about not putting grease in the gearbox side because you don't want the
pressure from your leak (which is pretty high) to push grease into your p/s system. Make sure you have a factory steer wheel on it so it keeps rain
out of the top of the column.

You wouldn't have a link to that thread ? He's got like 1500 posts and it doesn't let you search threads.

 

[mtnxtreme]

OK I know its been awhile, I finally got the box rebuilt and swapped the pump to the new style with integrated tank, fired it up and oil is coming out the top of steering tube, right where steering wheel hits it, now what ?!?!?

 

[Sean in PA]

It appears that now your upper seal is leaking. When you rebuilt the steering box, did you follow the procedure in the manual for tightening down the large nut and then backing it off 1/6 of a turn and staking it in place?

Also, is the relief valve in the replacement pump properly shimmed for 650 psi? Most available on the market these days are shimmed for 100 psi when you buy them, as there were many more tractors that used an 1100 psi pump than the 650 psi pump.

 

[RM-MN]

(quoted from post at 21:43:05 06/05/22) It appears that now your upper seal is leaking. When you rebuilt the steering box, did you follow the procedure in the manual for tightening down the large nut and then backing it off 1/6 of a turn and staking it in place?

Also, is the relief valve in the replacement pump properly shimmed for 650 psi? Most available on the market these days are shimmed for 100 psi when you buy them, as there were many more tractors that used an 1100 psi pump than the 650 psi pump.

There is a brass bearing just above the upper seal that will work its way out of place if you grab the steering wheel to help pull yourself up onto the tractor. If that brass bearing has worked its way out of place the seal will leak. Ford should have put a bearing of some kind at the top of the tube just under the steering wheel to avoid that problem but they didn't. I made a Delrin bearing for mine to give the steering shaft support at the top.

 

[mtnxtreme]

I had a machine shop rebuild the pump so I don't know. As far as the pump psi, I just looked at the pump I bought and its an 1100 psi but lists my tractor as a fit, on the bottom of the e bay ad it says to order a different number for the 650psi, is this really that big of a deal will it cause the leak ?

This post was edited by mtnxtreme on 06/06/2022 at 09:56 am.

 

[mtnxtreme]

(quoted from post at 04:19:42 06/06/22)

(quoted from post at 21:43:05 06/05/22) It appears that now your upper seal is leaking. When you rebuilt the steering box, did you follow the procedure in the manual for tightening down the large nut and then backing it off 1/6 of a turn and staking it in place?

Also, is the relief valve in the replacement pump properly shimmed for 650 psi? Most available on the market these days are shimmed for 100 psi when you buy them, as there were many more tractors that used an 1100 psi pump than the 650 psi pump.

There is a brass bearing just above the upper seal that will work its way out of place if you grab the steering wheel to help pull yourself up onto the tractor. If that brass bearing has worked its way out of place the seal will leak. Ford should have put a bearing of some kind at the top of the tube just under the steering wheel to avoid that problem but they didn't. I made a Delrin bearing for mine to give the steering shaft support at the top.

I read a lot of posts about the upper seal leaking because the shaft has pitting and it sneaks paste seal, so I picked up a kit that has a sleeve and oversized seal, and the brass bushing you refer to, but RM MN on here said he thinks its the pump having too much pressure, all the research I've done says it is the shaft being pitted or grooved ? And that brass bushing also.