Power steering failure

[thethee]

Recently I dragged my '75 Imperial out of its hiding place and came to the conclusion that the power steering on it had failed. The power steering pump was struggling and at almost every steering input sounded like it was about to destroy the pump. It also provided little to no power assistance.

This morning I removed the power steering belt and spun the pulley by hand. I felt resistance building up followed by something ticking inside the pump. This seemed like there's a blockage somewhere. After that I disconnected the high pressure hose from the steering gearbox. This time the pump spun freely and produced a steady stream of nasty looking fluid. I used a rebuild kit on the pump about 2 years ago.

This led me to believe that my pump is fine and the problem is with my steering gear. Seeing as how that is a pain to deal with it seemed best to stop and ask for advice. So, thoughts? Is there some diagnosis and service that can be performed with the unit still in the car?

Forgot to mention, it's the 1.06 Federal pump and the FSM provides little help with this issue.

 

[Big_John]

Sometimes you get air in the system from a loose return hose that will cause those symptoms. AMHIK.

I'm not saying that's the cause here... Just my experience that drove me nuts (short drive) trying to find it.

 

[thethee]

If that is the case, how would you remove that air?

 

[CBODY67]

If you have already rebuilt the pump, yet still got "rusty looking" fluid out of the system, you might try flushing the system. First the pump by placing the output line in a bucket. Fill the reservoir and then turn the pump until that fluid is in the bucket. Cycle repeat until fresh fluid comes out.

Then figure out a way to then include the gear in the fluid flow without the old fluid contaminating the fresh fluid. Something like a transmission flush machine might be adapted to the power steering lines, possibly? But with power steering fluid in the machine. You can use atf to flush the system, but my experiences have been that a power steering system full of atf will later leak and have issues like that until the atf is removed and replaced with genuine OEM power steering fluid. I used the old GM #1050017 power steering fluid, which looked exactly like the Chrysler power steering fluid.

It might be that just getting fresh fluid throughout the system might make things act better.

Hope this might help,
CBODY67

 

[Big_John]

If that is the case, how would you remove that air?

Tighten the return hose and then slowly turn the wheels side to side.

Here's a good refill procedure that touches on this: Suggestions for Filling Your Power Steering System — Powersteering.com

 

[Big_John]

I used the old GM #1050017 power steering fluid, which looked exactly like the Chrysler power steering fluid.

Probably is the same stuff. Chrysler used a lot of Saganaw (GM) pumps for one thing.

 

[thethee]

I should have mentioned that I have the front of the car on jackstands but with the wheels still touching the ground, to take some of the weight off of the wheels.

Followed the procedure you mentioned @Big_John and something changed, I can already feel power assistance again. Still need to check it with the weight fully on the front wheels though.

New item:
Now, with the engine at idle, there is no noise while moving the wheel except it squeals at full lock on either side. If I have the wheel centered and I increase rpms it also squeals.

The squealing at full lock isn't new but I'm pretty sure the squealing at higher rpms is new. Traced it with certainty to the power steering pump.

Thoughts?

 

[thethee]

Nope, no dice...

Tightened the hoses, tightened the belt, removed jackstands, and checked fluid level. Same behaviour as before unfortunately, almost no assist..

Just trying to turn the wheel a bit away from centre feels and sounds like it is at full lock when it's obviously not.

Edit. Trying to figure out if this is a pump issue or a gear issue. I'll probably tear into the pump first as that's the easier of the two I guess.

 

[thethee]

Completely disassembled, cleaned, inspected, and reassembled the pump. Found nothing out of the ordinary.

Next step is to try and flush the steering gear. I'm thinking to disconnect the return line from the pump and into container and spin pump. Considering to pull spark plugs and use starter motor to spin it or just do it by hand. Thoughts?

My FSM also points towards the valve assembly atop the steering gear. Anyone have any experience with removing that?

 

[thethee]

Got around to removing the valve body on top of the steering gear box. Upon removal discovered orange colored o rings which have seen better days. Is the color of ant significance or can I just replace with some generic black o rings from my toolbox?

 

[1970FuryConv]

Got around to removing the valve body on top of the steering gear box. Upon removal discovered orange colored o rings which have seen better days. Is the color of ant significance or can I just replace with some generic black o rings from my toolbox?

Because of pressure in the system, I would not use any O-ring. I'd call Firm Feel and get the right stuff. Do it right do it once.

 

[thethee]

I believe I have fixed my power steering issue.

To summarise, I've disassembled and cleaned my power steering pump, disassembled and cleaned the control valve assembly, and flushed the gearbox. Tapped the valve assembly to fix the self steer issue like the FSM prescribes.

I am now a firm believer to never, ever, ever use ATF as a PSF substitute. What came out of the steering gearbox was a dark reddish brown colour. It's the only thing that was clearly out of the ordinary. Now it's a nice clear green.

 

[thethee]

Because of pressure in the system, I would not use any O-ring. I'd call Firm Feel and get the right stuff. Do it right do it once.

The o-rings were factory but upon closer inspection were still okay and so I just put the orange ones back