Power Steering/Hydro Boost Problem

Tiny
HANNIBALREX
  • MEMBER
  • 2004 GMC YUKON
  • 170,000 MILES
2004 GMC Yukon SLT Flex Fuel. Vortec V8 5.3L. The steering has difficulty turning to right, but not left. There is also a whining noise when either hitting the accelerator or attempting to turn right. When accelerating, the steering is somewhat easier to the right, but still hear whining noise. Best way to describe the noise is like a dentist's drill.

I replaced the power steering pump, bought new from OReilly auto parts. Whining noise did not change, and still did not correct the steering problem to the right or the noise issue.

It is equipped with hydraulic boost breaking system connected to the power steering pump. I did the break test during engine off and restart and seems to be okay.

The noise is obnoxious and would like my steering to operate normally. When I replaced the PS pump, I bled the lines by turning wheel many times without improvement. Fluid levels normal with power steering fluid.

Does the whole system need to be flushed including the hydro boost or is this a totally different issue?
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Tuesday, April 23rd, 2013 AT 12:19 AM

5 Replies

Tiny
HMAC300
  • EXPERT
When youreplace a pump you need to go to lock on steering meaning one way as far as it will go then theother and do the same you have to hold it there to work out air. But have your rack checked.
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Tuesday, April 23rd, 2013 AT 5:47 AM
Tiny
HANNIBALREX
  • MEMBER
Flushed the system again. I used the seafoam trans tune and flushed with new power steering fluid, then refilled with power steering fluid. The steering to the right did not improve at all. New pump, new flush and fluid did not correct it. :(

Turned the wheel all the way to lock on both sides, holding to let the air escape.

The noise is still there, but way less noticeable than before. It will get a bit louder when accelerating. Probably still some air in the system? Any other tricks for bleeding additional air out of the system?

I have not had the steering rack checked, but what other symptoms of rack problems could I potentially start to notice?

Lot of questions, just frustrated. Thanks.
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Tuesday, April 23rd, 2013 AT 9:31 PM
Tiny
HMAC300
  • EXPERT
Have the rack checked first because all your work may go for naught. A lot of times the noise in pump is from the valve but there could still be air in system but really not turning easy in one direction is a sign of abad rack. Of course it could be something else. One other thing this can be aggravated by worn tires, low tire pressure and tires that are larger than stock. Also be damn sure you use power steering fluid and NOT transmission fluid type A because that will damage the valve inside the power steering pump.
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Wednesday, April 24th, 2013 AT 6:43 AM
Tiny
HANNIBALREX
  • MEMBER
Thanks hmac.

I do have some larger, not stock, tires on 22 rims.

After further inspection, the steering gearbox seems to be the culprit. Another thing I did not do is buy OEM new power steering pump, but went with the OReilly part which I hear was a bad choice since it is probably remanufactured.

Local wrecking yard has a steering gearbox from a 2006 yukon that had 50K miles on it. States in grade A shape for 85 bucks, probably rolling the dice, but perhaps its worth a shot? As far as I can tell there is no change from the 2004 models to 2006.

What are your thoughts on that?
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Wednesday, April 24th, 2013 AT 9:17 PM
Tiny
HMAC300
  • EXPERT
Hey it's your time and money but having the larger tires will give you the same problem I suspect after a period of time. Remanufactured parts should be ok but a lot of times it depends on the remanufacturer good luck
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Thursday, April 25th, 2013 AT 5:40 AM

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