1974 Ford 3000 blowing power steering fluid out fill opening

[roadpacker]

I know this problem has been discussed, but I will start a new thread in the hopes of getting advice for my problem. I have a 1974 Ford 3000 diesel with power steering and the tractor is blowing fluid out of the fill opening on the pump when the cap is removed when the engine is running. This is a Plessey pump that has the reservoir mounted to the pump with one bolt that is directly under the return line fitting.It will also sometimes blow fluid out the steering column, but not often.I have drained and changed the fluid,but not changed the filter with no improvement.I remove the reservoir cover and the old filter looks like the original Ford filter.It looks to be in good shape. I have removed the pump and have a rebuild kit of o-rings and shaft seals The pump looks like new with no side play in the shaft. Turning the gear by hand, I feel the seals resist so I think the shaft seals are good.My question is should I go ahead and tske the pump apart and replace all o-rings and shaft seals, or put the pump back on with a new filter and fluid ans see if it still blows fluid out the fill opening with the cap off? The power steering works fine with the exception of blowing fluid out.Any help and advice is appreciated.

 

[Harry in Ky]

More than likely the shaft seals are causing your problem. The pump is off, you have the kit, just do it.

Bear in mind though, if the pump is original (or simply old enough) the double sided shaft seal you find won't be in the kit. You will get two single sided seals that will go in back to back. There probably won't be enough room for both seals and the snap ring. You may need to omit the snap ring and do what you can with what you have,

Most importantly, when you take the pump apart pay CLOSE attention to what came from where, and how the parts face each other. The parts are NOT self explanatory as some pumps are. The bearing blocks can fit more than one way but only the right way will work. I like to lay all parts out in sequence as it comes apart. Clean and inspect each part one at a time, keeping them in direction and in order as I go along.

 

[TractorTech]

Also, pay attention to where the seals ride. You may be able to offset the seals to avoid any grooves in the shaft left by the old seal(s), but you may have to purchase a Speedi-sleeve to renew the seal wear area.

 

[roadpacker]

More than likely the shaft seals are causing your problem. The pump is off, you have the kit, just do it.

Bear in mind though, if the pump is original (or simply old enough) the double sided shaft seal you find won't be in the kit. You will get two single sided seals that will go in back to back. There probably won't be enough room for both seals and the snap ring. You may need to omit the snap ring and do what you can with what you have,

Most importantly, when you take the pump apart pay CLOSE attention to what came from where, and how the parts face each other. The parts are NOT self explanatory as some pumps are. The bearing blocks can fit more than one way but only the right way will work. I like to lay all parts out in sequence as it comes apart. Clean and inspect each part one at a time, keeping them in direction and in order as I go along.

Thanks Harry, for the fast reply and good advice- just what I needed. You are correct about the seals in the kit, they are both singled sided, and measure .246 tall, which would probably compress to about 15/32. How important is the snap ring, and what happens if it is left out? The kit has a butt load of o-rings of various sizes and I am wondering if they are all used.One thing I forgot in my first post is that I put a pressure gauge in the pump discharge line and with the tractor running and the steering wheel not being turned the gauge pressure was zero. When I turned the steering wheel from left to right and right to left like I was bleeding the air from the pump. the pressure would go up to about 200. Turn the wheels straight and pressure went to zero.Is this normal?At that low of pressure why would fluid belch from the fill opening?Thanks again.

 

[sd455dan]

Thanks Harry, for the fast reply and good advice- just what I needed. You are correct about the seals in the kit, they are both singled sided, and measure .246 tall, which would probably compress to about 15/32. How important is the snap ring, and what happens if it is left out? The kit has a butt load of o-rings of various sizes and I am wondering if they are all used.One thing I forgot in my first post is that I put a pressure gauge in the pump discharge line and with the tractor running and the steering wheel not being turned the gauge pressure was zero. When I turned the steering wheel from left to right and right to left like I was bleeding the air from the pump. the pressure would go up to about 200. Turn the wheels straight and pressure went to zero.Is this normal?At that low of pressure why would fluid belch from the fill opening?Thanks again.

This may not help
but when refilling the ps system I generally only run it till it pukes fluid
Just went through similar symptoms on the Ford 550 TLB when changing the hydraulic Ram line fitting seals.
I let it sit for an hour or two refill again rinse and repeat, all the return line mixed in air can cause a volume increase.
Just trying to eliminate initial aeration on a refill If the shaft seals have been eliminated as a culprit.

 

[Harry in Ky]

Thanks Harry, for the fast reply and good advice- just what I needed. You are correct about the seals in the kit, they are both singled sided, and measure .246 tall, which would probably compress to about 15/32. How important is the snap ring, and what happens if it is left out? The kit has a butt load of o-rings of various sizes and I am wondering if they are all used.One thing I forgot in my first post is that I put a pressure gauge in the pump discharge line and with the tractor running and the steering wheel not being turned the gauge pressure was zero. When I turned the steering wheel from left to right and right to left like I was bleeding the air from the pump. the pressure would go up to about 200. Turn the wheels straight and pressure went to zero.Is this normal?At that low of pressure why would fluid belch from the fill opening?Thanks again.

The pressure the pump develops has nothing to do with air in the fluid or oil running out the filler. Replacing the shaft seals usually takes care of that.

The pressure really isn't all that important. Once working, if it steers, it's probably okay. That style pump was used on a number of tractor models, and the relief setting could vary from around 600 PSI to as much as 1200. The 3000 would be in the lower ranges, and would only build to that point when you steer in one direction to the end of stroke and hold the wheel there. Just turning back and forth will only develop what it takes to move the wheels. With the steering wheel centered the pressure should be near zero that's normal.

 

[roadpacker]

The pressure the pump develops has nothing to do with air in the fluid or oil running out the filler. Replacing the shaft seals usually takes care of that.

The pressure really isn't all that important. Once working, if it steers, it's probably okay. That style pump was used on a number of tractor models, and the relief setting could vary from around 600 PSI to as much as 1200. The 3000 would be in the lower ranges, and would only build to that point when you steer in one direction to the end of stroke and hold the wheel there. Just turning back and forth will only develop what it takes to move the wheels. With the steering wheel centered the pressure should be near zero that's normal.

Thank you Harry,I figured the pump pressure was dependent on movement of the the steering wheel. With no steering wheel movement the pump pressure is pretty much static until the wheel is moved left or right.Is this correct? The shaft seal(or the 2 seals in the rebuild kit rather than the one original double lip seal) that I need to replace is the seal in the flange housing of the power steering pump and NOT any of the seals in steering column or control valve.Is this correct? I sure hope so because tearing into the steering column and control valve is probably above my pay grade. I think I can handle the pump ok.I just wanted to be sure that I understand which seal I need to replace before I start taking the pump apart. Once the reservoir and filter are off, the pump looks to be fairly simple to take apart. Thanks again, I appreciate all the good advice and instructions.

 

[Harry in Ky]

At this point there should be no reason to worry about the steering column or control valve. Nothing much in there that would contribute to air in the fluid.

 

[roadpacker]

Thanks Harry, that's what I wanted to hear.I'll start cleaning the outside of the pump and get ready to crack it open.When I replace the one double lip shaft seal with the 2 single lip seals supplied with the kit does one face toward the drive gear and one toward the pump body? Sorry to ask so many questions, but I ain't very smart and if things aren't simple like Ned and his 3rd Reader I don't understand them too well.

 

[FordnMassey]

Hi Roadpacker,

I recently had the same issue on a '67 Ford 3000 and everything Harry in Ky says matches my experiences. To further the explanation, air is sucked into the pump, likely thru a shaft seal and foams the oil, increasing the volume until it spews from the filler.

My reading and observations found that the double seal was to allow the inner one to seal the oil and the outer one to exclude dust. My kit also lacked a double seal and I could not fit two in the space provided, so I installed one with lip facing inward only. It works fine.

Hardest part of the job is the cleanup before opening it. The orings will become self explanatory. Beware of scoring the shaft seal seat getting the old seal out as I did. Luckily it still sealed.