Power steering issues.

BIGMAN738

MEMBER
2007 GMC SIERRA
104,000 MILES

I started having power steering problems awhile back and the dealership told me I needed to replace the pump. Which I did to no solution. I've since replaced the hydroboost as well and all of the lines. Symptoms include and it started out as random but I would have little or no power steering at low speeds. Parking lots, etc. Now I have NO power steering but there is no audible whine from the pump. You can feel it, however, in the steering wheel and the brake pedal. The only options left are a bad replacement pump or the gearbox. Any help would ne greatly appreciated.

Monday, January 2nd, 2012 AT 10:42 PM

5 Replies

RIVERMIKERAT

MECHANIC
6,110 POSTS

Dumb question, bot gotta ask: Was the belt replaced properly? Is the pulley spinning? IS the pulley oversized to reduce drag on the engine? Do you have power steering at higher engine speeds, like on the freeway? Check hoses for obstructions. Check gearbox for proper flow characteristics.

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Monday, January 2nd, 2012 AT 10:57 PM

BIGMAN738

MEMBER
3 POSTS

Yes, the belt is on and operating properly, the pulley is spinning properly and is also properly aligned. Yes, at higher speed there is power steering but it is still labored. I've replaced all the lines and each is free of improper kinks, routing etc. There are no leaks as well. How do I go about checking the flow characteristics of the gear box itself?

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Monday, January 2nd, 2012 AT 11:03 PM

RIVERMIKERAT

MECHANIC
6,110 POSTS

You would have to know what the fluid routing is through the gearbox. I probably shouldn't have mentioned that.

It sounds as though the pump is being under-driven. You have SOME power assist at higher engine speeds. This is either an over-sized pulley, or a defective pump.

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Monday, January 2nd, 2012 AT 11:16 PM

BIGMAN738