# Ford 3400 power steering leak



## Farmer Mike (Feb 25, 2020)

Hello to all tractor owners. I'm an old timer but new to this forum. I recently replaced the aging and worn-out steering wheel on my '72 Ford 3400 diesel and have been perplexed with a foolish problem. Before I replaced the old steering wheel there was a minor leak of power steering fluid coming from the top of the steering shaft under the steering wheel. Since I put the new steering wheel on the leak has become more severe leaving a puddle of fluid on top of the transmission cover plate. I attempted to put some felt bushings and large washers under the steering wheel to stop the leak but to no avail. I have the VERY THICK Ford/New Holland service manual and have pored through lots of pages looking for a solution to this problem but I haven't been able to nail it down. It is probably a seal located somewhere inside the shaft or a missing seal that went missing during previous ownership. I've owned "Henry" for about 25 years. I'm mechanically capable of doing the work but I need a starting point to get this leak behind me. Thanks for any help.
Mike


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## HarveyW (Sep 15, 2014)

Howdy Farmer Mike, welcome to the tractor forum.

See item #35 on the attached parts diagram: 
https://www.messicks.com/nh/52383?sectionId=23445&diagramId=52383_258807

This is a seal installed in the base of the steering column. If your steering is working fine otherwise, do not go any deeper than removing the steering column to get to the seal. Inspect the steering shaft for evidence of corrosion/pitting in the area where the seal lip seats on the shaft. If corroded, you may want to install a sleeve on the shaft. There are sleeve kits available for this purpose on the internet.


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## Farmer Mike (Feb 25, 2020)

HarveyW said:


> Howdy Farmer Mike, welcome to the tractor forum.
> 
> See item #35 on the attached parts diagram:
> https://www.messicks.com/nh/52383?sectionId=23445&diagramId=52383_258807
> ...


Thanks very much, Harvey, for helping me to locate the problem. I would also like to thank you for introducing me to Messick's. This morning I will be going into my 4" thick New Holland Service Manual to see what is involved with removing and disassembling the steering shaft. Never done that one before but I'm willing to dig in.
I recently had to remove and replace the splined flange and shaft on the front of the crank that drives the front loader PTO pump. While I had that all apart I replaced the radiator and gave "Henry" a new paint job. 













Thanks again.
Mike


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## HarveyW (Sep 15, 2014)

I noticed that "Henry" was looking pretty good for an old tractor. I did that seal replacement on a Ford 3600 about 30 years ago. Sometimes those thick manuals are a PITA. You might consider an I&T shop manual for your tractor. They are on the other end of the spectrum, written for mechanics, they assume you know how to do certain things and leave out details.

One other thing.....avoid using the steering wheel to pull yourself up onto your tractor. The steering column is not designed for extreme lateral loads....the seal can get damaged.


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## Farmer Mike (Feb 25, 2020)

HarveyW said:


> I noticed that "Henry" was looking pretty good for an old tractor. I did that seal replacement on a Ford 3600 about 30 years ago. Sometimes those thick manuals are a PITA. You might consider an I&T shop manual for your tractor. They are on the other end of the spectrum, written for mechanics, they assume you know how to do certain things and leave out details.
> 
> One other thing.....avoid using the steering wheel to pull yourself up onto your tractor. The steering column is not designed for extreme lateral loads....the seal can get damaged.


When I did the repairs on the front end I found a whole lot of "sins" committed by the previous owner(s) and repaired them all. I tried my best at panel-beating to undo the dents that the tractor suffered and then the steering leak popped up. I had not known about I&T and after looking at the web page that is where I'll go for the new manual. The NH manuals are most likely aimed at the dealer repair shop crowd. Thanks for the heads up on I&T and also about the steering wheel shaft weaknesses. Never to old to learn something new.


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## Farmer Mike (Feb 25, 2020)

Harvey,
Got to work on getting the steering shaft seal repaired. Took the cowl apart, figured out the dismantling drill and removed the shaft tube. The steering shaft was in good undamaged condition, no need to dress it, and ordered the part from Messicks. I appreciate that contact.
As soon as the rain stops I'll be pressure washing the uncovered parts and when the seal arrives it'll all be ready to get back together.













Here are a couple of photos of both the shaft seal surface as well as the worn shaft seal.
I'll keep the forum up on the progress and should anyone need a shoulder to lean on in going through the same procedure don't hesitate to ask.
Mike


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## Hoppy (Nov 3, 2019)

Thanks for all of the details Farmer Mike! I've enjoyed reading the posts and have new information and ideas for a couple of my old tractors.


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## HarveyW (Sep 15, 2014)

Hoppy, you also disturbed seal #33 when you pulled the column tube. That should also be replaced to ensure it doesn't leak. 

https://www.messicks.com/nh/52383?sectionId=23445&diagramId=52383_258807


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## Farmer Mike (Feb 25, 2020)

Got that covered Harvey. Thanks, though, for the kick in the butt. When I saw the O-ring in the base, I added it to the list.
Also, when I replaced the very-aged steering wheel I noticed that there wasn't enough good thread to catch the hold-down nut so I leveled off the top of the shaft, center punched the top of the shaft, drilled and tapped a hole. Gave it plenty of grabbing depth, got a big washer and bolted it down. The splines were in excellent condition. Worked well.
An additional note on the front loader PTO pump at the front of the crankshaft... it is a Cessna hydraulic landing gear pump. I can assist with helpful information for anyone who is having problems with removal and installation of the front shaft.
Anyway, Sun's shining and gotta get working on "Henry."


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## Farmer Mike (Feb 25, 2020)

Well, the story continues... As I was reassembling the steering shaft housing I failed to mark the appropriate locations of the removed hydraulic lines on the right side of the valve. (Found out later that I probably didn't have to remove them, but, I did)
The hydraulic lines got put in the wrong holes and when I started the engine the steering was locked. After removing and reinserting the lines one of the female threads got cross threaded. Went and ordered a new 7/16 X 24 tap and die (bottoming type) and cleaned up the boo-boo.
Evidently the damage was beyond repair even though I tried to use Loc-Tite "green".
After trying some other old-timey cures I had to order a new steering valve body (WOW! $495.00)
Got the new one delivered and when I was removing the check valve from the old one (required action) and installing on the new one some of the spring-loaded detents and springs fell out on the table.
Hmmm? Of the ones that fell out of the holes there were two with different profiles and a ball-check. (See the attached photos) Didn't see which holes that they came from so I now am awaiting advice from either a higher authority or from someone who may be able to supply a "blow-up" diagram for the power steering valve body (P/N C5NN3A730B) for an aging 1972 Ford 3400 diesel.
Thanks for all of your assistance up to this point.
A real learning experience!


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## sixbales (May 18, 2011)

The guru for Ford Power steering is *ultradogMN*. See attached link.

https://www.tractorforum.com/threads/ford-3000-power-steering-problem.18974/


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## Farmer Mike (Feb 25, 2020)

sixbales said:


> The guru for Ford Power steering is *ultradogMN*. See attached link.
> 
> https://www.tractorforum.com/threads/ford-3000-power-steering-problem.18974/


*Sixbales and UltradogMN*... Thanks for the heads-up on the assembly information. Now for the final question. I noticed that the steering shaft will "screw" up and down while it is standing undressed, so to speak. When I reassemble the steering valve body and redress the shaft what position should the shaft be on the upward and downward movement? This is a true learning experience. Thanks to you all!


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## Farmer Mike (Feb 25, 2020)

*Sixbales and UltradogMN*... Thanks for the heads-up on the assembly information. Now for the final question. I noticed that the steering shaft will "screw" up and down while it is standing undressed, so to speak. When I reassemble the steering valve body and redress the shaft what position should the shaft be on the upward and downward movement? This is a true learning experience. Thanks to you all!


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## sixbales (May 18, 2011)

As long as the front wheels and steering gears have not moved, I THINK you can get back to original settings. All you have to do is get the shaft back bottomed out in the bottom bearing without moving wheels or gears in the steering gearbox. 

The shaft must move up and down a few thousandths of an inch for the power steering to function correctly. To calibrate this, after the PS valve is installed, tighten down the locknut to remove all endplay, then *back off the locknut 1/6 turn, *then stake the locknut so it cannot move (1/6 turn is one hex flat....hope that makes sense to you).


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## Farmer Mike (Feb 25, 2020)

Front wheels haven't turned and are straight forward. I'll take your advice and let you know how this turns out
As a side note, the new valve did not have the "other" type of plugs, just the old one. The new one had all 4 of the spring type items. I inserted the "other" cupped ones with the ball bearings into the appropriate location in the new unit. Tomorrow is another day.


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## Farmer Mike (Feb 25, 2020)

OK, I have the valve body mounted with the old check valve installed and all 6 hydraulic lines inserted and snugged. 
_I learned an important fact today. I was on the phone with Jeff Crane at Cross Creek Tractor re: the springs and plugs. I learned that the updated units do NOT need the cupped plugs with the ball bearing inserts any longer. All the four holes will have the 2 plugs and springs inside. Guess ya learn something everyday. BTW, Cross Creek had the lowest price, by far, of any supplier on the net. Free shipping (on orders over $450) and one-day delivery from Alabama to NC!_
Now to get back to the matter at hand. In understanding what *Sixbales* posted for the steering shaft positioning, I might need a little more enlightening on that. 
When this is finished I will be noting some of the "odd stuff" that I encountered along the way for anyone who may need to learn as I did. Got a bunch of great teachers out there and I'm willing to learn and to pass it on. Thanks,
Mike


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## sixbales (May 18, 2011)

Sounds to me like you are in good shape. You will have air in the system after filling it with fluid. For ease of steering, I recomment jacking up the front axle to get both wheels off the ground. Fill the PS reservoir. Steer full left or right. Your choice. Refill the reservoir. Steer to full stop in the opposite direction. Refill the reservoir. That's it. Here's hoping it works for you!!


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## Farmer Mike (Feb 25, 2020)

Thanks *Sixbales*. The part that I need a bit of enlightenment is the following:
_"As long as the front wheels and steering gears have not moved, I THINK you can get back to original settings. All you have to do is get the shaft back bottomed out in the bottom bearing without moving wheels or gears in the steering gearbox."_
Does this mean that the position of the steering shaft on vertical movement is not a consequential position? This 79 year old US Marine needs some help here.
I appreciate your help.
Thanks.
Mike


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## sixbales (May 18, 2011)

Howdy Mike, 
You are correct, the steering "timing" is preset (locked) in the steering gearbox. I should not have made that comment. See item #6 on attached diagram. When you turn the steering shaft the "nut" moves up and down to move a steering gear. If you turn the shaft and the gear doesn't move (as you observed), the shaft will move up or down.


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## Farmer Mike (Feb 25, 2020)

Sounds good, *Sixbales*. I'm reassembling the mess today and will follow-up with the results.
Thanks,
Mike


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## Farmer Mike (Feb 25, 2020)

Well, "Henry", my Ford tractor, came back to life today. All of my learning and listening paid off and the power steering is back on the payroll once again.
Had a couple of trying moments carefully tightening the flare fittings but, except for two "my bad" moments, the repair is done.
"My Bad' moment #1: After I got everything back together, or so I thought, and decided that it was time to start the engine for the test sequence, I hit the key.
With engine revs at 600 I dropped the front loader and raised the front wheels off the ground. Looking down I saw leakage. Nooooo! With as much patience that I could muster I looked around and it appeared to be coming from the upper right flare fitting.
Shut 'er down and gently re-torqued the nuts with the flare wrench.
Started it up again and more leaks but this time it looked like it was coming from the body of the pump assembly. Then it dawned on me... I only snugged the three hold down bolts and didn't torque them. OK, Done!
Started Henry up again and after making sure that the fluid reservoir had enough I started to move the wheels back and forth with no ground friction involved. Checked and topped off the fluid and got all of the air out of the system.
Now it was time to give it a road test. My driveway is about 2,000' long so I was ready to grade it out with the box blade.
"My Bad' moment #2: after double checking all nuts, bolts and fittings again I made my way to the seat.
Put it into 1st and let out the clutch. NOTHING! No movement no nothing! Checked the clutch linkage and anything that might have caused this failure.
Mumbling under my breath didn't do any good so I went over my "check list" that I usually do whenever I look for any mechanical problems on any vehicle or aircraft that I may be in control of.
SHAZAM! When I parked Henry and got him ready for the operation I put ALL systems in neutral, including the "High/Low" range shifter.
Found Low, breathed a sigh of relief and rolled away. After about a half hour of grading, he passed all tests.
Thanks to all who helped or watched along the way, especially *Sixbales* and *Harvey W. *
If anyone who is experiencing similar problems with this particular model (1972 Ford 3400 diesel) I will be there to give any help that is needed.
Semper Fidelis.
Mike
USMC 1959-65
3 years in SE Asia 1/60 - 12/62


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## sixbales (May 18, 2011)

Congrats....


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