Sccsgm

Hi all im new here been reading a lot of good things here. I took my C5 into a local shop for the typical front ballancer issue. After i picked up the car my power stearing was jearking in some areas. I thought a little air it will work out. Shop is a mile from my house. 2 days later took the car out and the PS quit working about a mile from home. So back home i go. Its Sunday shop closed. So check ps fluid. Its ok. Little foam so i let it sit. Decided to bleed the system
remoned return hose and capped off nipple on ps tank. Turned wherls back stop to stop intil i bled about 2 quarts of PS fluid. GM approved. Connected hose. Still no ps. So followed manual for vac bleed. Up to 20 in of vac. Bunch of gurglind. Let it sit it droped to about 16 in and stayed 10 min removed vac started. Ran shut off. No fluid change still full. Vac again 5 min. Removed vac. Now PS works. But has air. Vac again. Now better. Went for a ride and ps went out in about 1/2 mile. Did the vac process again. Same thing works for 1/2 mile. The 3rd time nothing at all. No leaks. Speed sensor connected not loosing fluis. No noise from pump. Was a bit of noise when PS worked. The normal noise.
Any ideas?

Rob 02

I am wondering if they got the high and low lines mixed up when reinstalling the rack.

opticalmicrobe

no you can't mix the lines up...the are different sizes.

opticalmicrobe

yes, i've been through this exact same problem before (although i did work myself), it's the power steering pump itself. what happened is they did not bleed it correctly at the shop. (the vacuum bleeding you did is the absolute best way). Once the pump sucks air it usually burns it up internally. Then you get no noise and no power steering.
What you need to do is replace the power steering pump and use the vacuum bleed method (do it several times) and also turn the wheel back and forth a bunch with tires off ground (have someone watch for bubbles), then vacuum bleed it again. then after you do all that start it briefly (15 to 30 seconds), then shut off and recheck fluid level. it's actually hard to get the air out, and air will kill a pump.
pumps are relatively easy to change if you wanna do it yourself. get a new pulley as well as they usually break when taking it off to get pump off main bracket (they make ones with holes in it so you can get to bolts.)
hope that helps you out

Rob 02

Are you sure? Mine looks the same.

Just in case, reservoir/cooler is hose fitting is on the left (drivers side) and pump hose fitting on the right (passenger side).

Sccsgm

I asked him if it was possable that they switched hoses he said no. But?? What i have heard if you do switch hoses the rack will jam in either one or the other side. And cause a seal problem. When the pump worked it made the normal pump noise when it hit an air pocket it made that whining noise. Will the pump burn up that quick? I am running out of ideas but i dont want to throw parts at it. There was sonething about the speed sensor circuit that was said could cause this too. But the pump has pleanty of fluid no air in the oil so i guess i may have to replace it and see.

Thanks Guys.

opticalmicrobe

yes...they are same size lines, but the the nuts are slightly different sizes. and i dont' think the hose will physically go in the other spots anyhow. For sure they are different sizes.

opticalmicrobe

yes the speed sensor controls the magna-steer portion of the steering (meaning when you go faster it takes away how much power steering it gives you). to test just unplug the sensor...it'll will give you full power steering. Stopped it should have full power steering as well. You can suck out some fluid and check for tiny metal shavings (aluminum or copper). a lot of times when the pump fails it will leave evidence. OH, also remove the belt and pull out on the pulley....sometimes it happens to break the shaft inside the pump if it's shocked hard (like air pocket). if it's very loose or comes out...pumps bad.
Sometimes you'll get noise because there is still some movement and pressure in the system...but not enough to turn the steering. The actual way to test the pump would be to attach a pressure gauge inline on the pressure side.....then turn the wheels. You should get a good amount of pressure... 500-1500 psi or something like that...can't remember exact specification. you could do that to double check. there is a possibility the rack has failed...but it's not common at all

alxltd1

I believe the low pressure fitting on the rack going to the reservoir is a 16mmX1.5 o-ring base, the fittng on the rack receiving the high pressure line from the pump is a 18mmX1.5 o-ring base.

However, the fitting from the pump to the high pressure inlet on the rack is a 16mmX1.5 o-ring.

0steering_experts1

Hello,

Most likely debris has entered the pump causing the the flow control valve to stick open. You can test this by, revving the engine to 3000 RPM and see if you get power steering back. If you get power steering back then it is stuck open. If you do not get power steering back then debris may be plugging the screen on the pressure relief valve. This will cause the pump to be inoperable.

If debris has stuck the control valve open, in our experience, the pump will be damaged beyond repair. If it is debris blocking the pressure relief valve screen, it can be removed and cleared very easily allowing the pump to function again.

If you determine that the flow control valve is stuck open and the pump is damaged, we can offer you a brand new pump. Also if you determine that it is the debris blocking the pressure relief valve, you can contact our tech support line and we can provide you with step by step instructions on how to clear this issue.

Give us a call for either at 1-877-GO-TURN1!

Thanks,
Jeff

midnight01

Jack the front end of the car up so the wheels are off the ground.
turn the ignition on but dont start it
take the power steering cap off
Turn the wheel to lockout left to right about 15 times
Wait about 2 minutes
Do it again.
lower the front end and start the car and turn the wheels to almost lockout 5 times. Shut the car off
raise vehicle again,
same steps as above. That should do it.

I had a ton of air in my steering rack so I did that procedure and it got rid of my problem. I literally watch the bubbles come up while I did it. If that doesnt resolve it then like it was said the rack has some issues or the pump is shot. You can check the pump easily by using a turkey baster and siphon fluid out until it is really low and then start the car. You should see fluid moving in the pump when you turn the wheel or just being stationary. If nothing is moving it could be the pump. That method was what i used to test the pump and may not be the most scientific lol.