Troubleshooting Power Steering

[Matt in TN]

I just bought a 1973 Ford 4000 and the power steering (hydro assist, it looks like) doesn't work. You can turn the wheels while moving, but not at all while sitting still. The prior owner said he's been running it that way for years, and only recently found out it was "supposed" to have power steering.

In my fluid/filter changing "just bought a new/used tractor" routine I filled the PS pump/resevoir, which was definitely low. I did not check to see if it was completely dry, but I would assume so from the PO's stories. I'm thinking the pump is bad, but I'd like to verify this before I blow $300 on a new pump. What sort of pressures should I be seeing out of the pump? Is there a checklist I can work through to troubleshoot the entire system and verify it's the pump (or find what else might be wrong)?

Lastly - does anyone have any recommendations on where to get a new pump or other parts, other than the dealer?

Thanks -

Matt

 

[FULLPULL]

If it worked good after adding fluid you might only have to replace the seals in the pump. My guess would be the pump is worn along with the seals .You may be able to get a rebuild kit and you will need the bushings inside of the pump.

 

[Matt in TN]

No - adding fluid made no difference to the operation. I'll see about a rebuild kit - I didn't think about that option.

 

[Wayne County Hose]

If the 4000 is anything like the 3000, I have quite a bit of experience with this. Unfortunately, all BAD experiences.

 

[Matt in TN]

I would guess they're very similar - share your experience, Hoseman!

 

[Soundguy]

I believe once the housings wear, repair is by replacement.

Probable a lost cause at this point.. but has the ps filter been changed?

if it ran without oil for an extended amount of time.... you might as well go fishing with it and use it to keep your boat stationary by tying a rope to it..

soundguy

 

[RickB]

I can't give you a pressure spec without knowing if it is a general purpose 4000 or an SU model. Also, late general purpose models have a higher pressure spec than early, so give me the year. Pressure test by installing a gauge in the pump output and deadheading the pump for a short period of time. Then tee the gauge in the pressure line and hold the wheel at full lock briefly. This will compare the condition of the pump/ relief valve to that of the steering valve. Your dealer may have access to aftermarket pumps supplied by A&I or other aftermarket sources that will be substantially less costly than OEM. The only parts available for these pumps is a seal kit which is a waste of money unless you have a pump that builds good pressure but leaks externally.

 

[Matt in TN]

It's a 1973 model. I have not yet changed the PS filter. I think you're right soundguy, but I may pull the pump and tear into it just to see what it looks like before I get a new one on the way. The dealer recommended aftermarket as well, and quoted me $300-350 for a pump ($700-800 for a New Holland pump).

I'd be curious to tee in some gauges and know for sure what's going on, but it may be a waste of my time at this point. Would a 0-1000psi gauge give me enough headroom, or could the pressures go higher than that?

Edit - not sure if it's general purpose or SU (what's SU - "Sport Utility"? ) How would I tell?

 

[Soundguy]

SU.. ome call it special utility.. some super utility.

SU would be a machine that had the light duty swept back front axle of a ford 3000.. IE.. radius rods and such.

I like a 0-3000 psi gauge for hyd applications on ag tractfors.. but you generally can get by for less on the PS systems..

soundguy

 

[FULLPULL]

The last power steering pump that i priced was around 7 or 800 bucks . If it was 3 or 350 i would have gone new . When you take the pump off of the tractor see if the bushings are worn by rocking not turning the gear it will have play in it at least the last one i worked on did. There should be a parts break down on the NH web site under your model of tractor.