Power Steering Not Working but no visible leaks

[whalenlg]

I did a quick u turn last week and heard a clunk as I went fully left and then voila - the power steering assist disappeared.

Put the car on stands today and there are no leaks. Fluid is full in reservoir, belt is intact and pump is turning.

Fluid and Hose from reservoir to pump replaced this 9 months back.

Pulled the tie rod boots - no fluid. No fluid anywhere on the rack or hoses connected to the rack. No fluid coming from the pump.


Rack was rebuilt 2 years ago and pump 5 years ago (~4.5k miles since then).

UPDATE - I had it on jackstands with the engine running - no fluid movement in the reservoir and the steering takes much more effort to turn the wheel than with the engine off.

So - it would appear to be either:
(1) Pump just stopped working, but not leaking. Not sure if that's likely, but rebuilding the pump again is easy.

(2) The teflon part inside the rack failed and now the fluid just flows back and forth inside the rack.
Are there sources for that part (this is the 1 part that doesn't come with the rebuild kit).

Any other possibilities?

Suggested diagnostics to confirm/rule out a pump failure? Really don't want to rebuild the rack again (might just ditch it for manual rack).

[Tom]

Sorry about that. Not my area per se, but I'd lean toward the pump. When you turn full lock, do you hear any groaning to suggest it's creating pressure? When you looked for fluid moving in the tank, did you have someone turning the wheel? No fluid moving, and harder to turn with the motor running both suggest the pump. I'd be inclined to take the belt off and see if that makes it easier to turn (on jack stands). If so, then that would be enough for me to pull the pump and open it up for a look-see...

[whalenlg]

Yes - I did look at the reservoir while
My son moved the wheel and couldn’t see any movement.
I just went back and tried to see if there’s any groan at either end (no) but now turning the wheel with the engine on is easy again. Not sure what to make of that.
I may not be able to get it off the stands soon - need some parts to finish up the only944 shifter, linkage etc. project.

[rheidtman]

Yes, suspect the pump is at fault. I have seen the main shafts fail, rendering the pump useless and then just 'free wheeling.' As noted, the reseal is simple and will most likely highlight the source of the problem.

[Tom]

Yes - I did look at the reservoir while
My son moved the wheel and couldn’t see any movement.
I just went back and tried to see if there’s any groan at either end (no) but now turning the wheel with the engine on is easy again. Not sure what to make of that.
I may not be able to get it off the stands soon - need some parts to finish up the only944 shifter, linkage etc. project.

I'd still suspect the pump, though not sure what to make of it springing back to life. Any chance the belt is slipping?

[whalenlg]

New data....
I left the car on stands overnight with the wheel turned all the way right.

Started it up and it was hard to turn to the left. Turned 1/4 of the way left. Hard. Turned all the way back to the right, easy.

Turned to center and it started getting hard at 1/4 of the way. Repeated right, then more left, then right than all the way left. Same pattern. It was hard to the left but only if I hadn't turned it that far before.

After that - left and right were back to easy. It was like it needed to be "broken in" before it got smooth.

[Tom]

New data....
I left the car on stands overnight with the wheel turned all the way right.

Started it up and it was hard to turn to the left. Turned 1/4 of the way left. Hard. Turned all the way back to the right, easy.

Turned to center and it started getting hard at 1/4 of the way. Repeated right, then more left, then right than all the way left. Same pattern. It was hard to the left but only if I hadn't turned it that far before.

After that - left and right were back to easy. It was like it needed to be "broken in" before it got smooth.

Air in the system??

[whalenlg]

Air in the system??

That appears to be it.

How it got in there is a mystery. The only correlating event was taking that sharp u-turn. I suppose its possible that the fluid got plastered to one side of the reservoir and air got sucked in.

Since the last post, I added a small amount of DexronIII and then did 5 lock to lock spins of the wheel with the engine on.

Let it sit overnight (it's still on jacks).

No more difficulty turning in either direction. I'll road test it soon - need to complete the Only944 shift upgrade tonight.

[whalenlg]

Ok - no luck on the roadtest. Still hard to steer. It got easy turning right for a few seconds and then hard again.
Ordering pump rebuild as that’s the cheapest, easiest possible solution.

[Tom]

Ok - no luck on the roadtest. Still hard to steer. It got easy turning right for a few seconds and then hard again.
Ordering pump rebuild as that’s the cheapest, easiest possible solution.

I've seen people put the hose in a bucket and run the motor for a few seconds to see if it's making pressure. Probably an epic mess though. You might drain the fluid and check for chunks before putting in the new pump.