Ford 4500 steering stops working

[bookel]

I recently had a lot of work done to the steering on my 4500. They rebuilt ram that moves the steering as well as made new pins and bushings for the entire mechanism to be able to be adjusted and operate correctly. When they dropped it off it was steering fine. That was about a month ago and I've barely moved it since. Yesterday I finally got to using the tractor. When I first started the steering was working excellent. As time wen t on, maybe over the next half hour the steering got harder and harder to the point that the power assist is non existent. I turned the tractor off and took a break. About an hour later I came back and the steering was fine again. Then after another half hour or so of using it the same thing happened. This thing is a brute without the power assist. I checked the hydraulic fluid at the reservoir and it was full. The filter however was dirty and had not been changed. I confirmed it had not been change by calling the shop where I had the work done and they in fact did not change it. I am in the process of acquiring an new filter. Besides changing that out what else could be the problem? I know I should just send it back to the shop and tell them to finish the job. And I may end up doing that. But if I can get it going on my own with a relatively simple fix that would work out best. Those guys charged me an arm and a leg for these repairs and the towing for the tractor to their shop aint cheap either. So far it feels like I'm out lots of cash and no results other than sore arms.

 

[mitch504]

Sounds like you are saying it works with cold oil, but not with warm oil?

Do you have the separate steering reservoir, or does it draw from the main hydraulic tank?

What kind of oil are you using, if it's separate?

I hate to say it, but working cold and not hot, is classic for a worn pump. Does your steering pump get hotter than the things around it?

Hot oil is much thinner than cold oil, so it is bypassing somewhere. It is common on these old girls for the relief valve spring to get weak with age and cause low pressure, and thus hard steering. I've never seen a relief valve change with temperature, though, it either works or it doesn't. If the steering linkage was out of adjustment it would steer easy one way, and hard the other.

You probably need a pressure guage and a few fittings to find this problem.

 

[bookel]

Would that be new Holland p/n 87607369?

 

[bookel]

Oh and mine is a year 1968 so same reservoir. It was at a new Holland dealer when they did the steering work so I would think they would replace the hydraulic oil with the correct type. I had leaky couplings on the return line so I topped off with S Super Trac 303 from Tractor Supply. It says to use in Fords and others. Here is the link http://www.tractorsupply.com/tsc/pr...03-tractor-hydraulic-fluid-5-gal?cm_vc=-10005
I'll check for pump temp when I get back home Monday.

 

[mitch504]

Nope, you don't get off that light, that's the main hydraulic pump, that runs your loader, and backhoe if so equipped.

Your steering pump is located at the right front of the engine, mounted directly to the engine, and run off the timing gears.

Depending on the age of your tractor, and whether it has an integral reservoir, it will be: 81816585 or D8NN3K514KC.

I wouldn't jump to ordering a pump just yet, I'd be sure that was the problem, and, depending on what you find when you open it up, the pump may be repairable. The system says most of the internal parts are still available, but I can't swear to that.

On edit: I just saw your new post after I answered.

That's fine, these old girls will work with nearly any hydraulic oil. That question was mostly for if you had the separate reservoir, I've seen guys use ATF, power steering fluid, and other stuff in them.

There is a little strainer inside the hyd. oil tank where the steering suction line comes out, it could be getting clogged, and then the stuff falls off when it's sitting.

 

[bookel]

Is that the big 1-1/4" line that comes out of the reservoir you are talking about for the strainer? I can check this stuff Monday, again I am out of town til then. I'll be replacing the filter cartridge as well. That thing was visibly dirty. Just hoping the simple stuff may pan out.

I will probably be asking what things I need to have in regards to checking the pump in regard to gauges and the process for checking it. I am mechanically inclined but never done this before. Seeing that it would cost me a goo $350 trucking the tractor to and from the shop plus their labor I'd be willing to purchase and tools I need to diagnose.
Thanks

 

[mitch504]

Nope, that's the suction line for the main pump. The steering suction line is about 1/2", seems like it comes off the tank on the left side, on or near the bottom. It has a screen inside the tank on it, too.

As far as gauges, you'll want about a 3000 psi gauge, (about $15 at northern tool) and a short 1/4" hydraulic hose, and some adapters.

 

[bookel]

I hate to be a pain but do you mind posting a link to which gauges I need and the adapters. 1/4" hose I can find easy. When I head home Monday morning I can pass right by a Northern Tool so I can pick that stuff up right then. Otherwise its an hour and a half out of my way or wait for mail order.

I suppose to get at the screen in the bottom of the tank I can reach inside to get at it? Or should I drain the reservoir first and then get to it?

 

[bookel]

http://www.northerntool.com/shop/tools/NTESearch?storeId=6970&ipp=24&Ntt=3000+psi+guage

Any of these gauges preferred?

 

[Tinkerer]

I use an oxygen tank gauge that can NEVER - EVER be used for oxygen again. Grease gun hoses can withstand the pressure you are dealing with. Or even a hydraulic hose.

 

[oarwhat]

I use an oxygen tank gauge that can NEVER - EVER be used for oxygen again. Grease gun hoses can withstand the pressure you are dealing with. Or even a hydraulic hose.

I did the same thing and threw the gauge in the drawer. A few years later my oxygen gauge died so I used it never thinking about the oil. It blew and hit me in the eye. No damage but real close. Be careful.

 

[oarwhat]

You say they rebuilt the ram. This can also leak when hot if done incorrectly

 

[bookel]

I am going to pick up one of those gauges from NT in the morning. I'll also get a short hydraulic hose while there. What adapters should I get to do the testing I will be doing? Is there a test port on that steering pump?

"You say they rebuilt the ram. This can also leak when hot if done incorrectly"
Good to know. I will get it good and warm and have my wife work the steering while I inspect the ram..

 

[mitch504]

If the ram is leaking, it will probably be internal, either on the cylinder side, or the valve side, and you won't be able to see it. If the pump is doing what it should, and there isn't oil pouring on the ground somewhere, that's the problem.

Before trying the pressure test, turn the engine with the fuel off for a second and an open hose into a bucket, this'll eliminate a supply problem.

There is no test port, ideally, you would put a tee at the pump discharge, with a valve downstream. To do a minimal test, just deadhead the gauge onto the pump discharge after the steering stops working. Spin the engine for a few seconds with the fuel off to make sure it's not going to go high, though it almost certainly won't. Then start the engine, you should get 1250 psi at idle, if not, run the rpm up and see what you get. If it's significantly low, you can try putting a cut off piece of a 1/4" bolt about an 1/8" long under the relief valve spring and see if this changes it, if it doesn't, repair, rebuild or replace the pump.

Good Luck, and let us know what you find,
Mitch

 

[bookel]

If I am correct this is my steering pump? The line in the purple circle is the pressure, blue circle is pressure relief, green is return? What are the bolts in the other two circles for?


This is the steering ram. Purple is pressure and green is return?


I foloowed what I assume is the pressure line to this joint. Is this a good spot to put a tee, valve and pressure gauge? It appears to 1/4' fitting. What type of thread is this? JIC? Surely its not NPT?

Just trying to get a good understanding of what I am doing. I picked up a gauge, 3' 1/4" hose and a couple of fittings from NT this morning. Looks like I'll be running back out to get a tee and probably;y some adapters to make this work. I don't mind. If the type of fitting this is can be identified to me it would save me a lot of trouble sourcing the fittings and adapters I need to purchase.
Thanks.

 

[jimg984]

looks like that tubing has bad kink in it hard for me to see tho GL

 

[davo727]

I have a 68 4500. I replaced all the o rings in the power steering pump. Easy job, the old ones get hard and you get no pressure. You can get the o ring kits cheap from any of the big tractor parts places like yesterdays tractors or a bunch of others. Most have kits listed on the e bay.

 

[davo727]

Heres a pic during my pump reseal. From the thread I made on another forum of the full hydraulic steering conversion on my 68 Ford 4500 here http://www.mytractorforum.com/20-ford-new-holland-tractors/211740-full-hyd-steering-4500-a.html

 

[davo727]

Seal kit part number: DHPN3A674A I got it from agkits online. $27.64 currently.

 

[mitch504]

To start with, I'd just deadhead the gauge into the pressure line from the pump anywhere I could. If you can't get 1250 that way, you won't need the tee and the valve, because you'll know the problem is the pump. My guess is that the pump is the problem.

I think the fitting out of the pump is O-ring boss, and the top of the elbow is -06 male JIC, and that fitting by the air cleaner is compression, but may be JIC, but I can't remember for sure.

I typed the post about how to test it at lunch today, and I was going to go to one in my shop yard awaiting a new flex plate, and unscrew them and see what fittings they are, but, I got busy and honestly forgot.