losing power steering under acceleration

[swisherred]

it would be good to be clear which valve....The steering control valve (top of the gear box)worked just fine before...I didnt take it apart until after things started acting up...and it was set back exactly where it was...by the factory manual procedure...I'm thinking its in the pressure relief valve in the pump.

 

[3C's & a D?]

I even took the valve apart and swapped the internal springs with the original ones in case they were different strengths because I found that there was a low pressure and high pressure version....no change.

Try the new ones? Did you try adjusting the valve when you had it in the air? You said, up and down, but it is adjusted side to side. And even if you think you put it back exactly where it was, it could be 1/64th of an inch off, which will make a huge difference. Maybe while working under the hood on something unrelated, it was bumped, and that is when the problem started?

 

[3C's & a D?]

it would be good to be clear which valve....The

The cast aluminum valve on top of the steering box, that the return hose attaches to, held on by two bolts.

 

[swisherred]

Ok...lets clear this up...

Pump relief valve...(inside the pump)...replaced o-ring and cleaned when rebuilt.

Steering control valve...(on top of gear box)...replaced o-rings and reset per fsm (up and down...controls left and right steer)

Return pressure valve...(aluminum nipple on lower end of the steering control valve)...replaced. Also swapped internals with original parts just in case, no change.

 

[swisherred]

I made no changes with it in the air this time...simply checked for symptoms.

 

[swisherred]

Prior to this happening, the only things I had changed were the fluid and the return pressure valve because I cracked it replacing the o-rings. The steering column had been out multiple times as well. Otherwise no changes were made prior to the issue showing.

 

[Big_John]

Prior to this happening, the only things I had changed were the fluid and the return pressure valve because I cracked it replacing the o-rings. The steering column had been out multiple times as well. Otherwise no changes were made prior to the issue showing.

So we are all on the same page, probably the best thing to do is figure out exactly, in chronological order, what has happened. I know this is frustrating.

Did these symptoms start before or after you started working on it?

If after, what parts did you work on/rebuild/replace/adjust

I think most of us, including myself, is thinking the issue is in the steering control valve.

 

[swisherred]

best I can recollect...

From Running and driving....
The return pressure valve was leaking so I replaced the orings, but cracked the body in doing so...replaced it.
running and driving again...
Decided to strip the engine bay and frame and refresh the engine....
everything reinstalled...
running and driving again...
Later after lots of unrelated brake and rearend work....
The PS pump was leaking so i decided a rebuild was in order. I replaced all the seals in it, but not the valve (machined to that body) and not the rotating assembly, but I did replace the O-ring on the valve..
I noticed a catch in the steering while in the driveway...
Tore into the pump again...found small amount of debris in the relief valve screen..cleaned it and reassembled...
still catching...
Control valve body was leaking...replaced the o-rings there...
still catching...
Reset the control valve per FSM...
still catching...
tore down the pump again...nothing found...
still catching...
replaced belt and sanded the pulleys to clean any paint out...
still catching...
replaced return hose...
still catching...
swapped return valve internals with the ones from the original cracked valve...no change...
still catching...
flushed all the fluid out and blew high pressure air through both side of the pressure hose...all clean and no issues..
still catching...
jacked up the car to check verify wander in the control valve as suggested...none found, catch still there but I can turn the wheel both ways just with no assist above 2500rpm

here we are....

 

[Big_John]

Just looking at the list, trying to figure it out logically, it looks like the problem first occurred after rebuilding the leaky power steering pump.

Then you noticed debris in the screen. I would wonder if that was a possible cause or symptom?

Seeing that you can move the wheel, but no assist, makes me wonder if you really didn't experience a true "lock up" while driving, but just really stiff steering. That kinda brings us back around to the pump again.

 

[3C's & a D?]

Sounds to me like its the pressure valve in the pump. Confirm???

Reading through the thread, and your list, this is about the only part in the system, other than the steering box, that wasn't replaced or rebuilt. I can't see it being the rotating assembly, or the steering box. Perhaps when you put the new seals in, the next weakest link was made apparent. Possibly the valve was having issues and that caused the seals to leak in the first place?

 

[swisherred]

PROBLEM SOLVED...
It had to be the pressure relief valve in the pump itself. I swapped in a new pump from a 68 charger and bled it real good with the wheels up and engine off....works great.

Now I just have to fix the alignment I just had done....they didn't center the wheel so in full right turn the pitman arm contacts the oil pan.

 

[3C's & a D?]

PROBLEM SOLVED...
It had to be the pressure relief valve in the pump itself. I swapped in a new pump from a 68 charger and bled it real good with the wheels up and engine off....works great.

Nice! Glad you got it figured out.

Now I just have to fix the alignment I just had done....they didn't center the wheel so in full right turn the pitman arm contacts the oil pan.

Damn it! Well, at least the car is keeping you busy.