[Reed]

I have spent my nights and weekends for the past few weeks working on my sister's 09 Enclave. 100,000+ miles. The trans was starting to slip and there was a rattling noise from the timing cover area, so I bit the bullet and dropped the K frame with the engine and trans installed, installed the Sonnax 3-5 wave plate repair kit in the tans and replaced all the timing chains, cam phasers, cam position sensors, guides, and tensioners.

"While I was in there" I figured I would never have this kind of access again, so I did a bunch of preventative maintenance on parts that didn't necessarily need replacing but would be much more difficult to replace with the engine and trans bolted back up to the body.

Among other things, I replaced the power steering pump and rack and pinion. Engine runs great and the trans shifts fine, but now I have VERY stiff steering. Almost as if there was no power steering at all.

The Enclave has the variable assist steering and I made sure to get a remanufactured rack and pinion with the variable assist option.

I bled the system and the pump is quiet now, it just is very hard to turn the wheel.

I am a compentent mechanic but I am used to older vehicles and non-GM vehicles. Any pointers on where I should look to diagnose a stiff steering system? Thanks in advance.

 

[ibis1]

Reed, Not sure what electronics come into play on a 2009, such as a pressure switch or transducer, but are you sure your new rack is identical to the old unit? Also is your steering angle sensor calibrated correctly at 0 degrees in the straight ahead position? I don't know if GM's software offer anyway to read pump pressure electronically, but if not, you would need a high pressure gauge and correct adapter to read working pressure of the pump. If pump pressure is good, you most likely have a defective steering rack. Good luck. One last thing and it is very rare, but are you sure your serpentine belt is installed correctly? I ran into a vehicle years ago (Not a Buick) that had the belt installed incorrectly and was turning the pump backwards. NEVER assume anything is correct.

 

[Reed]

Thanks for the input. I will look at all of those things. Worst case scenario I still have the original rack and pinion and power steering pump. It would be a pain to reinstall them, but at least the car would be driveable then.

 

[ibis1]

Reed, Hope it's something simple and let us know what you find.

 

[Nismo one]

I have spent my nights and weekends for the past few weeks working on my sister's 09 Enclave. 100,000+ miles. The trans was starting to slip and there was a rattling noise from the timing cover area, so I bit the bullet and dropped the K frame with the engine and trans installed, installed the Sonnax 3-5 wave plate repair kit in the tans and replaced all the timing chains, cam phasers, cam position sensors, guides, and tensioners.

"While I was in there" I figured I would never have this kind of access again, so I did a bunch of preventative maintenance on parts that didn't necessarily need replacing but would be much more difficult to replace with the engine and trans bolted back up to the body.

Among other things, I replaced the power steering pump and rack and pinion. Engine runs great and the trans shifts fine, but now I have VERY stiff steering. Almost as if there was no power steering at all.

The Enclave has the variable assist steering and I made sure to get a remanufactured rack and pinion with the variable assist option.

I bled the system and the pump is quiet now, it just is very hard to turn the wheel.

I am a compentent mechanic but I am used to older vehicles and non-GM vehicles. Any pointers on where I should look to diagnose a stiff steering system? Thanks in advance.

Sounds like a defective rack. My 2010 has just pressure switch for idle up, not much there as far electronics, should flag pcm code/code's if so, if there wasn't having a problem before and steering shaft is seated properly it's most likely a defective rack, good luck brother!

 

[Reed]

Finally got a chance to take another look at this. Steering is still hard to turn and does not seem to get any easier with RPM increase or road speed (well, it is a bit easier at speed since the tires are rolling, but I can still feel more resistance than is normal for a power steering equipped vehicle). Further, there is a small power steering fluid leak on the passenger side of the engine.

Again, power steering pump is new, rack and pinion is remanufactured, new(?) VES solenoid included with the remanufactured rack and pinion. No CEL or trouble codes.

My only thoughts about why there is poor power steering is (1) all the steering linkage parts are new and tight (ball jonts, tie rod ends) and (2) the new power steering pump whined loudly for a long time on first startup and has eventually grown quiet. I am thinking that the loud whine on the new power steering pump was the sound of the pump eating itself and it has now failed and is only providing minimal pressurization to the power steering system. (2.5) I used regular power steering fluid instead of Dexron VI.

My current diagnostic path is to replace the new power steering pump with the old pump (that did not have any problems), flush the power steering system, and refill it with Dexron VI.

Open to any suggestions.

 

[ibis1]

Reed, My gut still thinks you have a faulty rack. I have seen power steering pumps take an incredible amount of abuse from repeatedly being starved of fluid and never giving up the ghost. I don't blame you for swapping out your pump, since you have a known good pump, but I would stick with the dedicated power steering fluid rather than transmission fluid that does not hold up as well under the higher working pressure of power steering systems. Good luck.

 

[Reed]

I replaced the variable assist steering solenoid on the rack and the steering feels a bit better but is still stiff at slow speeds. I can hear the valves opening int he rack and pinion if I turn the wheel left or right, so at this point I am going to replace the power steering pump woth the old known good one and see if that gets me any improvement. If it doesn't, then the whole mess is coming out and I will be reinstalling the original parts.

 

[Reed]

Happy news.

Turns out the stiff steering was just air in the system. Driving the car around today greatly improved the feel of the steerng to the point that stiffness is no longer an issue. I am very happy I don't have to crawl back in there and try and remove the power steering pump or rack and pinion again. Thanks for the assistance.

 

[ibis1]

Reed, Glad your back in business. That's one thing about power steering systems, there is not a real method to bleed the system. It self bleeds as you drive it. Hope all stays well.

 

[Reed]

Reed, Glad your back in business. That's one thing about power steering systems, there is not a real method to bleed the system. It self bleeds as you drive it. Hope all stays well.

Thanks. I had ordered a power steering bleeding tool that works with a Mityvac to draw a vacuum on the power steering system to assist in bleeding all the air out, but this car seems to have self-bled all on its own. So far, so good. No other problems have popped up. It sounds much better running now that I have replaced the failed cam phasers.