MF- 202 Steering Valve

My 202 steering valve is leaking oil out of the top (steering shaft). It's leaking enough that it needs to be addressed. I understand the spool may be shot, but the leaking started suddenly. It steers easily. I'm using ISO 46 hydraulic fluid, it didn't have ATF in it when I bought it a year ago. When I tried to switch it to ATF, the steering got lumpy. I switched back to ISO 46 and it's been fine for the last 9 months.

Yesterday was the first cool day that we've had, that's when the leaking started. I am wondering what the ball checks do. They are spring loaded. If a spring was bad and the fluid thick (making the check lazy) could that cause the leaking?

It looks like a bit of work to pull the steering box. It would be a lot easier without loader on. The engine block is still leaking coolant into the oil. I would like to try make it until March (after snow) before getting into the motor. It won't get used unless it snows.

Should I pull the steering box and see if it's repairable, or should I leave it until I do the motor? If anyone has been inside the steering box or had one out, I have a few specific questions.

Thanks,
Stan Coryell
Mickleton, NJ

First question, do you have individual power steering cylinders on the front wheel linkage?

Yes, the steering valve is a bich to get to. My 202 was leaking fluid from the top of the column. It was a very bad leak. There was not driving it that way. I tried putting a new seal that goes into the bottom of the steering column. As a matter of fact I had it apart and together again 3 times. I even tried a speedy sleeve on the column where the seal rides.

I finally got so disgusted with it that I bought a new spool valve from an off road vehicle website. After installing that valve along with a new steering column and steering wheel, it now steers like a Cadillac. It was well worth.

Another thing, I don't know why you think it's going to be hard with the loader on it. My 202 had a loader and it didn't make any difference.

If you give me an email address, I can send you a couple links that show how and what I did and where to get the parts. This forum won't let me post those links here but since it's not about buying MF parts from YTF, I don't feel it's interfering with their business.

It's cost me about $650. to do the whole job but, that's for brand new parts. You may be able to find used parts but you have no guarantee that they will work or if they do, how long they will work. Send me your email address to [email protected]

This post was edited by Caryc on 11/15/2022 at 04:17 pm.

Thanks. I am familiar with your aftermarket valve thread. I really don't have time for another project before winter.

That seal you changed, in my opinion, is a dust seal to keep junk out of the hydraulic circuit. I think the spool should be self sealing.

Did you check the plungers or springs in you old one? This is not my valve, but it's what I'm expecting to find. The Service Manual describes completely rebuilding the steering box in which, the steering shaft has to come out. To do this with the loader arms in the way would be a hassle. Do you know if I can get the valve out without removing the steering shaft? I'm going to dig into it Saturday...


For Reference: [email protected]

(quoted from post at 10:33:15 11/16/22) Thanks. I am familiar with your aftermarket valve thread. I really don't have time for another project before winter.

That seal you changed, in my opinion, is a dust seal to keep junk out of the hydraulic circuit. I think the spool should be self sealing.

Did you check the plungers or springs in you old one? This is not my valve, but it's what I'm expecting to find. The Service Manual describes completely rebuilding the steering box in which, the steering shaft has to come out. To do this with the loader arms in the way would be a hassle. Do you know if I can get the valve out without removing the steering shaft? I'm going to dig into it Saturday...

<img src=https://www.yesterdaystractors.com/cvphotos/cvphoto140765.jpg>
For Reference: [email protected]

Click to expand...

No, the steering column is on top of the valve. You have to remove the dash cover and the column to get at it. I still don't see what the loader has to do with anything. Here are some pics of mine. You should also remove the whole air cleaner assembly for more room. You can see the steering column sitting on top of the valve with the three bolts holding it on in the first picture.

http://www.clccustomgrips.com/steeringbuild1.html

This post was edited by Caryc on 11/16/2022 at 11:35 am.

I thought the pitman shafts and arms had
to come out to pull the steering shaft.
Not too bad with the loader arms in the
way. Replacing the pitman shaft seals or
bushings would be tough. It doesn't matter
if I don't have to pull the pitman shafts.
Thanks for the pictures.

When I rewired the dash, I left enough so
I can pull it off without disconnecting
everything. It shouldn't be too bad of a
job. Thanks again.

I had this problem with a TO35. I did not want to buy a new spool so I went with this solution. Drill and tap a fitting just above the seal on the steering column. Run a line from there to T in with the return line back to the pump. Excess fluid that gets past the seal will then be directed back into the return line.
Not my idea, but I found it at the link below. It has been working perfect for at least 2 years now, and is MUCH cheaper than replacing the spool valve.

https://www.external_link.com/threads/mf135-detroit-power-steering-leak-from-vent.33905/

I had a similar problem with a TO35. Found a fix online that was much cheaper than a new spool valve.

https://www.external_link.com/threads/mf135-detroit-power-steering-leak-from-vent.33905/

Basically it is drilling and tapping the housing just above the steering shaft seal. Install a fitting and run a line that will T into the return line to the power steering pump. It allows excess fluid that gets by the valve to be returned to the pump without building up enough pressure to push past the seal.
I first tried replacing the seal and using a speedi sleeve but that didn't stop the leaking. This fix has worked for the past couple of years. I found it on the above link and I have now done the same procedure on my latest MF35 project to prevent the same problem.

(quoted from post at 19:51:44 11/16/22) I thought the pitman shafts and arms had
to come out to pull the steering shaft.
Not too bad with the loader arms in the
way. Replacing the pitman shaft seals or
bushings would be tough. It doesn't matter
if I don't have to pull the pitman shafts.
Thanks for the pictures.

When I rewired the dash, I left enough so
I can pull it off without disconnecting
everything. It shouldn't be too bad of a
job. Thanks again.

Click to expand...

The throttle linkage was hard to get at, both removing the dash and installing it. In my pictures you can see what I did to the dash so I didn't lose my mind trying to get at anything under it.

Notice the vertical and horizontal drilled holes in the dash. Do not remove any metal with any of those holes in it.

The previous owner did the big hole on the left and I thanked him for doing it. I did the other two holes. If you can do the whole job without cutting out any holes in the dash, you are a magician or you have miniature hands. Those holes make any future work that you have to do in that area a whole lot easier. The people that designed that dash gave no concern at all to future owners who may have to work in that area.

This post was edited by Caryc on 11/18/2022 at 12:08 pm.

Got into it. It's wasn't bad at all.

The steering box is full of hydraulic oil/ grease and the steering shaft is toast (from water intrusion). The spool and valve body seem tight with no scratches. The plunger springs and not broken. The thrust washer are fine ' I think these along with the plungers are the face seal for the spool and body.

I was incorrect, the steering shaft seal is not a dust seal. Is an oil seal, that has static oil pressure behind it.

Well, my steering box is back together. I'll get the tractor back together tomorrow. I don't forsee any problems. Wish me luck...

Good job Stan - hopefully you've fixed it!

Thanks!

All back together with no leaks. I drilled a 1/8" hole at the bottom of the steering cover, just above the seal. If any water gets in at least it will drain.

I also found that the upper pinion shaft was off one tooth when I pulled it apart. This is obvious when you try to set the backlash.

Pictures added.