Been awhile since I messed with the PS and want to throw this out for advice/input.
I have a hard steering issue that has been around for a few months. I checked for pressure at PS pump with engine running, there is pressure. In the reservoir I switched out ps fluid for type F as suggested here by a few folks. I then did the east to west stop to stop turns with fromt end on jack stands to bleed any air in the system. With front end on stands I can turn east to west with 1 finger no problems, steering on the street was that easy till a few months back. Once on the ground it's steering as if it's manual with no power.
I don't know enough about hydraulics to know if it's possible that the pump may be moving enough fluid with no weight on the front but once weight is applied the pressure level is not strong enough. This make sense? Over time the pump would lose power or ability to generate enough pressure? Again it was okay at one point.
I should throw in that all around I have 265/70-17's on aftermarket aluminum wheels.
I know there is a lot of experience on this site any thoughts, suggestions or ideas would be appreciated.

 

FoMoCo: P/S fluid is the same as Type F ATF.

 

Sounds like something is holding pressure back. Not fluid,pressure. Kink in a line or hose. Or the pump pressure control valve in the pump. I can't post Ford pics like Bill can. Hopefully he'll return and post one for me. It is basic # 3a561 in his pic.

 

Ask and ye shall receive.

 

It may be the high pressure flow control valve is bad and may need to be replaced.

Some guys have good luck with Lucas ps conditioner
It may be gunned up from the wrong fluids.
Orich

 

ND thanks for the parts breakdown.
I've never broke open a PS unit on the 1-5 scale where does it rank? I'm up for trying anything just want to know. Also part would be available at any Ford dealership or even online?

 

D6TZ-3A561-A (replaced D0VY-3A561-A) .. P/S Pump Valve Assy / Obsolete ~ 20 available NOS

I'll list some of the sources if you wish, but personally...I wouldn't mess with it, plus you'll also need a P/S pump seal kit.

Obsolete parts prices vary wildly from one source to another, and whatever you have to pay, add the shipping charges. The closest source to NV that has any is in TX

Whiz down to the auto parts store and buy a rebuilt pump. 1967/77 F100/350 is the same and it's also the same as 1970/77 LTD.

This pump has a steel reservoir, the pumps used 1978 and later have a plastic reservoir, will not work.

You will also need a puller to remove the P/S pulley from the shaft, available from auto parts stores, usually loaned out for free.

 

2x with Bill,
If you pull one down and not know what your looking or have a replacement parts it and it'll be a waste of time & $$.
Orich

 

Thanks guys I'll take that advice.

 

Yours may have the a removable high PSI control valve bolted into your reservoir where your high pressure line connect to. It will have a larger nut to remove it, once your high psi rubber/steel line is removed.

This high psi by-pass reduces the line pressure when you motor is like turning 2500-3000 rpm lowering the line psi back down to like 400 psi from 800-1000 psi at idle. So if it's stuck into the by pass flow mode that would make it harder to turn..

I don't know if you remove and get one from PnP Jy or maybe try cleaning your.

orich

 

The Ford P/S pumps used on 1965/77 cars, 1966/77 F100/350's, 1969/74 Econolines and 1973/77 Bronco's has a steel reservoir, the P/S pressure hose threads onto the pump.

1978: Ford changed the P/S pump on everything (except cars with Hydro-Boost & Econolines [beginning 1975] that used the Saginaw pump).

This new Ford pump (see pic) has a plastic reservoir and it's a different shape than the steel reservoir pumps. The P/S Pressure hose connects to the pump w/a qwik connect fitting.

This plastic reservoir pump cannot be used with FE engines (which were cancelled at the end of the 1976 model run), as due to its different shape, the FE's brackets will not bolt to it.

Plastic reservoir P/S pump: