PS Steering rack change w/bleed issue
 

Hi everyone,

So I had to replace a leaking PS rack on a 95 3.4L, and got new hoses, O-rings, etc to go with a reman rack. I've put it all back together, and now I'm trying to bleed the system.

Problem is that there is constantly some kind of air in the reservoir. I've probably turned the wheel over 100 hundred total times, and I'm still getting some tiny air bubbles. The initial larger amounts of air are gone, but these small bubbles keep rising to the surface after every wheel turn cycle.

I've checked all the hose connections, and don't have any leaks, so I'm not sure how to take care of this problem. Would doing a vacuum bleed be a good idea? Or, do I have an air leak somewhere else?

Power steering system is not a closed system, it will self bleed, Drive it, is it making any odd noises? Honestly I have rebuild hundreds of racks and I never did any type of bleeding.

Fill reservoir, turn rack stop to stop, is there any noise that should not be there, No, send it.

got to go hard over to hard over a bunch of times. they get a air pocket on the ends sometimes. do it without the engine running a few times then start and do a few times while running. let it set to allow air to settle up out of oil.

Thanks for the advice. I guess I'll try it again tomorrow. I was just trying to do this by the service manual I have...which is like "no bubbles at all!"

It seems like the amount of bubbles present are getting smaller each time, but I'm just hoping there is an end to it eventually. The amount of fluid in the reservoir has stayed constant throughout.

As far as noise, I ran it tonight and moved the wheel back and forth some, and had a little whirring when I reached each stop left and right.

Which is 100% normal.

I don't have the 95 manual, in the 94 manual there is no mention of bubbles, just to be sure I opened the 96 manual and there it is "no bubbles" I wonder if something changed or GM researched found air causing issues. All I ever did at the dealership was turn the wheels back and forth once on the lift, check fluid, once on the ground, check level again. test drive and send it. I could do a rack rebuild in about an hour 20 minutes. GM had a real problems with racks in cold weather even under warranty. I know I had days I did 3 racks and weeks I did 10. I never had a comeback. I could understand this if there was a cooler involved. Nice part about replacing the seals in the rack you don't need a front end alignment after like a new rack does.

the smaller bubbles are good. shoud get better each time. letting it set allows the tiny bubbles to settle up and get air out. it took a bit to get em outa my 00. it whined a bit too until all air was gone

Yes. drive it and keep bleeding or watch for less bubbles.

I got the car down and drove it out today, and I've got some noticeable power steering whine. I don't know if it's air or some other issue. I'm going to check for leaks tomorrow as well.

Problem is the alignment is pretty bad now after the replacement, so I'm not real comfortable driving it around too much, which makes it hard to see if the noise and air amount improve.

Well, no leaks and I drove it around the neighborhood some today. Seems to be doing alright, and from driving the pump noise has gone away. I'll check out the bubble situation again, but I think the job is done on my end and it's time for an alignment.

Thanks for the help everyone.