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Discussion Starter #1
2001 Silverado 1500 2wd
230,000 miles
4.8
Automatic

this is the second power steering pump the
Truck has had installed in the last 2 years
And it STILL. Howls. However this time around the steering at the steering wheel is very smooth. Before, on the first pump replacement, at low engine speeds it was extremely difficult to turn the wheels. Now, the pump still screams like a roots blower but the steering is silky smooth. Any insight? Thanks. Getting tired of the annoying howl the pump makes. Just want it GONE. Is there something bad in the steering rack causing this? Scratching my head at this point.
 

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2000 Silverado Z71 4x4 5.3L 460k+ miles w/ GM rebuilt motor and trans
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26 Posts
It could be as simple as a low quality or faulty replacement power steering pump. My replacement air compressor makes people question whether I dropped a diesel engine in my truck because it knocks so loudly.
 

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^^^What he said - always buy AC Delco 'PROFESSIONAL" equipment. When you replaced the pump did you bleed the air out of it? Once it's installed and the reservoir is filled, you start the engine and quickly shut it off, top off the reservoir and, do it again until it doesn't take any more fluid. Then, start it back up and turn the wheel lock to lock, and top it off again. If you don't, and you let the resevoir empty, you'll always have air trapped in the system and won't be able to get it out, causing it to howl.

My replacement air compressor makes people question whether I dropped a diesel engine in my truck because it knocks so loudly.
That's another example of improper installation, when you get a new/rebuilt A/C compressor, you drain it and add 4oz of oil, manually turn it until it rotates smooth, then add the remainder of oil (whatever your specifications call for) in the rest of the system, ie. accumulator, condenser, etc. Then add Freon, with the engine shut off, until it won't take any more. Then start the engine and idle it for about 5 minutes while adding more Freon to disperse the oil into the system. Now you can rev it up to suck the remaining Freon into the system. HTH
 

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Discussion Starter #4
^^^What he said - always buy AC Delco 'PROFESSIONAL" equipment. When you replaced the pump did you bleed the air out of it? Once it's installed and the reservoir is filled, you start the engine and quickly shut it off, top off the reservoir and, do it again until it doesn't take any more fluid. Then, start it back up and turn the wheel lock to lock, and top it off again. If you don't, and you let the resevoir empty, you'll always have air trapped in the system and won't be able to get it out, causing it to howl.


That's another example of improper installation, when you get a new/rebuilt A/C compressor, you drain it and add 4oz of oil, manually turn it until it rotates smooth, then add the remainder of oil (whatever your specifications call for) in the rest of the system, ie. accumulator, condenser, etc. Then add Freon, with the engine shut off, until it won't take any more. Then start the engine and idle it for about 5 minutes while adding more Freon to disperse the oil into the system. Now you can rev it up to suck the remaining Freon into the system. HTH
I FIGURED IT OUT.
it turned out to be a bad AC tensioner pulley or ac pump pulley. Not sure which but I took off the belt and it’s dead quiet. So relieved
 

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you removed the ac compressor belt then no noise . well the ac compressor can be the problem. the tension-er is possible also .. the ac compressor clutch bearing can also cause it .
 

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2000 Silverado Z71 4x4 5.3L 460k+ miles w/ GM rebuilt motor and trans
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I FIGURED IT OUT.
it turned out to be a bad AC tensioner pulley or ac pump pulley. Not sure which but I took off the belt and it’s dead quiet. So relieved
Great! Glad it was...simple? 😁 Sometimes we can't see past the "obvious" first diagnosis. (Guilty.)

One time I had a belt squeal I could not diagnose. It was intermittent when driving and more prevalent when turning. I could almost force it when turning. Spent a month looking for it. I thought it was my air compressor (see previous comment about horrendous knocking), but it was working and didn't appear to be slipping.

I finally gave up and started changing out parts one by one in the NAPA parking lot and test driving. Changed out tensioner pulleys, idler pulley, both belts, and yet it still happened. While lying on the side of the road under my truck, I saw a rub mark on the AC tensioner where there's nothing to rub. Then I noticed a collapsed engine mount. The collapsed engine mount was laying the AC tensioner on a frame bolt, causing the AC belt to loosen and squeal when turning right. When driving straight, the frame bolt held the belt tight with the pulley. 🤦🏽‍♀️

New engine mounts and a new AC tensioner arm later and we're good to go!
 

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2001 Silverado 1500 2wd
230,000 miles
4.8
Automatic

this is the second power steering pump the
Truck has had installed in the last 2 years
And it STILL. Howls. However this time around the steering at the steering wheel is very smooth. Before, on the first pump replacement, at low engine speeds it was extremely difficult to turn the wheels. Now, the pump still screams like a roots blower but the steering is silky smooth. Any insight? Thanks. Getting tired of the annoying howl the pump makes. Just want it GONE. Is there something bad in the steering rack causing this? Scratching my head at this point.
When ever you replace any component, including the newly found A/C never assume the pulleys line up perfectly. Go to a shop with a laser alignment tool and check the pulley alignment. Being off 1/32 due to a small manufacturing defect will cause belt noises that sound like pulley noises.
 

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Don't spray belt dressing, its only temporary. Take the belt off and run the motor for a minute. If the noise is gone it is the belt causing the problem - maybe its bad or maybe a component it goes over is misaligned putting stress on the belt. If the noise is still there with no belt, then its something else. Put the belt back on and spray water at each area the belt touches a pulley or component, and see if the noise gets worse. Water will make it slip more and make more noise. It might help you find the source of the slip - water pump, idler pulley, alternator, etc. Then check those items for alignment and good pulleys and bearings. Remember the alignment can be off a small amount not discernible to the eye, and make a noise or even jump off at high speed. Get a laser alignment of pulleys at a good shop.


 

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Great! Glad it was...simple? 😁 Sometimes we can't see past the "obvious" first diagnosis. (Guilty.)

One time I had a belt squeal I could not diagnose. It was intermittent when driving and more prevalent when turning. I could almost force it when turning. Spent a month looking for it. I thought it was my air compressor (see previous comment about horrendous knocking), but it was working and didn't appear to be slipping.

I finally gave up and started changing out parts one by one in the NAPA parking lot and test driving. Changed out tensioner pulleys, idler pulley, both belts, and yet it still happened. While lying on the side of the road under my truck, I saw a rub mark on the AC tensioner where there's nothing to rub. Then I noticed a collapsed engine mount. The collapsed engine mount was laying the AC tensioner on a frame bolt, causing the AC belt to loosen and squeal when turning right. When driving straight, the frame bolt held the belt tight with the pulley. 🤦🏽‍♀️

New engine mounts and a new AC tensioner arm later and we're good to go!
That's why they say you run out of money, before you run out of guesses. Get a thorough inspection and diagnosis before you start throwing parts at it.
 
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