Power Steering pump noise with Hydroboost

[dunce79]

I have 61 Apache with an LS3 swap. Using a GM factory type II pump for an f-body that puts out 2.7/3.1gph and 1200-1300psi. The pump has a smaller than factory pulley on it (5 inch as opposed to 6). 89-90 Thunderbird rack and pinion along with a CPP hydroboost kit.

Originally my issue was self applying brakes which I fixed by adding a second return line to the reservoir. The return from the rack was overwhelming the return line, backing up into the hydroboost... causing the brakes to self apply.

With that resolved my issue is now the power steering pump making loud groaning/gear noises... sort of like a supercharger sound.

I appear to have all the air bled out of the system, not seeing anything in the reservoir after running now so I think that can be ruled out.

From some research I think I have a few things to try but looking for opinions as to where to start first.

1. Add a power steering cooler. Fluid and reservoir is getting damn hot and it does seem to only occur once everything is up to operating temp. Seems like a good idea, problem or not.
2. put in a different flow control valve to reduce the flow from 3 to 2gph?
3. use a pressure reducing kit to adjust the pressure lower (the smaller pulley may be causing more output and thus working the pump harder?
4. replace the power steering pump
5. replace the pulley with a 6 incher (though really, adjusting the pressure from the pump with a kit should have the same effect? And not require me to buy a new serpentine belt.

Suggestions from the experts? : ) thx!

[SCOTI]

Originally Posted by dunce79

I have 61 Apache with an LS3 swap. Using a GM factory type II pump for an f-body that puts out 2.7/3.1gph and 1200-1300psi. The pump has a smaller than factory pulley on it (5 inch as opposed to 6). 89-90 Thunderbird rack and pinion along with a CPP hydroboost kit.

Originally my issue was self applying brakes which I fixed by adding a second return line to the reservoir. The return from the rack was overwhelming the return line, backing up into the hydroboost... causing the brakes to self apply.

With that resolved my issue is now the power steering pump making loud groaning/gear noises... sort of like a supercharger sound.

I appear to have all the air bled out of the system, not seeing anything in the reservoir after running now so I think that can be ruled out.

From some research I think I have a few things to try but looking for opinions as to where to start first.

1. Add a power steering cooler. Fluid and reservoir is getting damn hot and it does seem to only occur once everything is up to operating temp. Seems like a good idea, problem or not.
2. put in a different flow control valve to reduce the flow from 3 to 2gph?
3. use a pressure reducing kit to adjust the pressure lower (the smaller pulley may be causing more output and thus working the pump harder?
4. replace the power steering pump
5. replace the pulley with a 6 incher (though really, adjusting the pressure from the pump with a kit should have the same effect? And not require me to buy a new serpentine belt.

Suggestions from the experts? : ) thx!

I would verify what the fox body rack can flow as well to make sure the set-up allows what the R&P needs & possibly not be another restiction.

[dunce79]

The vendor says the rack can handle 1200psi no prob and the steering is great right now.. good assistance but not too twitchy.

[SCOTI]

Hhmm.....

[dunce79]

I think this is solved. I cut the pressure down a bit in the pump by using the borgeson shim kit. Then added a power steering cooler. No issues with it since. I did replace the pump while i had things apart just for piece of mind but I don't think that was the culprit. Brakes and steering are still great and now no pump noise.