no power steering unless rev engine

[JJ 109]

Stock LS1 power steering pump with aftermarket Al reservoir. . New/reman gen 3 power steering box 2.5 turn.

When the car is idling, I have no power assist. If I rev the engine to ~2000 RPM, I have assist.

Any thought where to start?

[130fe]

Did you bleed all of the air out of the system (new PS box)?

[JJ 109]

I would have to say no. I am have never had to do that before.
I am not aware of a process

[c4racer2]

Fill system. Crack the feed line at the box and let fluid drain out.
Start motor with front end in the air and go lock to lock several times slowly. Keep checking level in reservoir don’t let go low. That should pretty much do it.

[David Pozzi]

The PS system is self bleeding. Any air winds up in the reservoir.
If the LS pump was used on a car with Rack & Pinion steering, the pressure setting is lower than needed for a Saginaw box.

[TheJDMan]

I have to agree with what David said.

[UMI Tech]

Companies like Turn One and Lee(?) can build pumps, or modify your pump, to the correct flow rate.

[JJ 109]

I had stated above it’s a 3rd gen (F body) box. So yes like the older Saginaw/Delphi box. (Non rack and pinion).

This is not uncommon setup however. Never heard of anyone else having this issue.

Not clear what my issue is still.

[c4racer2]

His point was if the pump on your motor is for a car that came with rack and pinion steering it will not work with a box. Steering box requires higher pressure.

[pitts64]

Take the pressure relief valve out of the pump and remove all the washers-shims.. You may have to pick up the Borgeson relief valve kit..
https://www.summitracing.com/parts/b...SABEgKhT_D_BwE

[JJ 109]

His point was if the pump on your motor is for a car that came with rack and pinion steering it will not work with a box. Steering box requires higher pressure.

I understood his point. I was just simply pointing out this combination has been proven numerous times to work.

[JJ 109]

Spoke to turn one this afternoon. Thier opinion was the presssure valve was likely stuck form debris etc.

The pump would be able to produce 1200-1300 psi which should have no issue with a steering box.

Guess I’ll be looking to replace it, with a rebuilt one.

[vette427-sbc]

If you open the reservoir after the car has been running for a few minutes what does the fluid look like? Foamy?
I know you dont want to hear this, but I just went through the same thing... borgeson box in a 66 mustang with a pump from a fox body (rack & pinion car)... very little assist until around 1500RPM. Changed out the pump for a Saginaw pump from a steering box car and it had the correct assist.

[c4racer2]

Agree - 1200-1300 is the right pressure for a box. So if that's the pump you are supposed to have - either it's wrong pump or not working or it could have a strange air trapped situation. What does the hose routing look like?

[David Pozzi]

Spoke to turn one this afternoon. Thier opinion was the presssure valve was likely stuck form debris etc.

The pump would be able to produce 1200-1300 psi which should have no issue with a steering box.

Guess I’ll be looking to replace it, with a rebuilt one.

Try removing the outlet fitting and flow control valve behind it. Don't lose the spring. the spring should normally push the valve out to about flush with the casting, if it doesn't then it's stuck. That valve can stick if there's a tiny shaving or debris & the stock pumps don't have a filter of any kind. Flush out the system and replace the parts and test again. It's a good idea to put a filter in the steering box return line.

If you install a new pump, you need to insure the system is clean or it may happen again.

[JJ 109]

Try removing the outlet fitting and flow control valve behind it. Don't lose the spring. the spring should normally push the valve out to about flush with the casting, if it doesn't then it's stuck. That valve can stick if there's a tiny shaving or debris & the stock pumps don't have a filter of any kind. Flush out the system and replace the parts and test again. It's a good idea to put a filter in the steering box return line.



If you install a new pump, you need to insure the system is clean or it may happen again.

Agree. I will give that a try before I replace it

[JJ 109]

Apparently the valve was stuck, and broke free and fixed itself.



All good now. Get lucky every now and then, hopefully will not reoccur.

[David Pozzi]

Add an inline filter in the return line