The Stovebolt Site Forums The Shop Area General Truck Talk PS pump whines.

I’m looking for some collective wisdom.
1964 230ci engine. Rebuilt and runs well.
Original inline six PS pump brackets too. All double groove pulleys line up nicely.
Just replaced a slightly leaky PS pump that also whined ALL THE TIME.
New PS pump also whines ALL THE TIME. Very disappointed that the whine is still there.
I’m using a 1974 C10 PS gear box with an Edelmann 71307 high pressure hose, which just happens to have the correct fittings on both ends.

I have the correct diameter PS pump pulley too and it’s original.

My though is that there may be too much pressure on the high side causing a constant whine.
Your thoughts?

Have you tried connecting the pump to another PS gearbox? It's possible there's a restriction of some sort inside the steering gear that's causing the pressure relief valve in both pumps to bypass constantly. You don't even have to mount another box on the frame or connect the Pitman arm- - - -just connect the hoses to it, start the engine, and see if the whine goes away. If so, go ahead and swap it out. If not, keep searching.
Jerry

Usually is a belt slip or lack of friction. Also if the fluid is frothy or with bubbles then air is getting into the system on the low pressure side considering you did say it was leaking.

I just bought a nice PS gear box as a spare. Great timing on my part. Haha! I’ll try your suggestion HRL. I will comment that the PS works very well.
I’ll report back what I find.

Most of the time, as said, it's just air needing to work it's way out after time. Be sure it stays FULL. Hopefully you have the correct fluid. Clean fluid. Fill while not running and turn wheel lock to lock 6-7 times while running. Drive around in a parking lot making back and forth turns. Take belt off and check to see if pump feel right when hand turned. We are talking whine, not squeal.

A low pressure hose leak will constantly suck in air. Check that hose and ALL it's clamps/fittings!!!!!!! Otherwise air will never get expelled and whine will never go away.

I think proper procedure is to fill while not running.
Also jack it up and turn the wheels many times one lock to the other, still not running.
Top off the fluid and finally start it for the first time, again lock to lock and check fluid.

Different pumps or applications may have different flow control valves in the pump, the fitting that the outlet hose screws into. You may have a high flow valve in there and the squeal is the pressure relief valve working double time.
There ought to be plenty of reading about this on the interweb once you know what to look for.
this gives you the idea of what's going on. http://www.gmtruckcentral.com/articles/2013/powersteeringmods/

Yes, I goofed it up. Left off a word. Fill while not running. Edit made.

I have had good luck turning lock to lock with running. Never done the lock to lock not running becasue I've never jacked up a vehicle to add/check fluid. Some things in the books are a waste of time.

Jay,
I had a 69 camaro with a 250 p/s pump leaked had it rebuilt it whined. Brought it back the rebiulder exchanged it for another, it whined. Moral of the story, needed a new belt.

New belt due to arrive soon. Needs one anyway 'cause this one is old. I did apply a little extra pressure to the PS belt while it was running by pushing a wheel against it by hand. No change in the whine. I'll do some more diagnostic work tomorrow.

Easy to tell if whine is caused by air in the fluid, it will be foamy or have a lot of bubbles when you look at the fluid in the reservoir. Does the whine sound like the sound when you turn the wheel all the way to lock or is it more of a high pitch whine, which is caused by air in the fluid. Anytime you open up the hydraulic system you introduce air and it must be removed by a procedure similar to that suggested by Grigg. Do it before you start the motor. Its too late for that advice so you have to let it sit for a day or two to let the air work its way out then do the back and forth lock to lock procedure. Good luck

I agree with all of the above but don't rule out a defective replacement pump. As many have realized, some of the aftermarket stuff is just poor quality. There are several grades of bearings and many re-builders go with the cheapest components available.
Fred

DING DING DING! Winner winner chicken dinner!
Watch the video. LINK HERE

Thanks to all who contributed.
I sure am a happy camper now that it’s fixed.
You can’t imagine how discouraged I was when the newly installed PS pump still had a whine like the old PS pump. I though for sure the old salvage yard PS pump was just worn out. HRL’s suggestion of plumbing the hoses to a new PS gear box was easy to accomplish because I had just acquired a really nice spare. The new belt arrived Friday and was on the truck within an hour of me getting off work and then ANGELS SANG! The reason I’m so happy is because I can now put PS on my 1963 C10 without fear of hearing an annoying whine like I had on my 1965.