Power steering pump

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JM in KY

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How common is bearing failure in a power steering pump? My ‘87 GMC 350 squeals / chirps after reaching operating temperature. Doesn’t happen exactly when the thermostat opens, but within a few minutes after. Also occasionally will start before getting that hot, maybe 150 to 160 degrees. Never when cold.

Belts are relatively new and spraying water, WD-40, or silicone on them doesn’t change the sound. Also have a new ACDelco water pump that I installed (partially because I thought that might be the source of the noise), which also did not change the sound or when it happens.

Alternator is fairly new and smog pump is disconnected. PS pump seems to be all that’s left. Reservoir stick says “full.”

Any other ideas?
 

JM in KY

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Should also mention that the sound doesn’t change with the AC compressor clutch being engaged or open.
 

Turbo4whl

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GM power steering pumps do not have a bearing, they have a bronze bushing. If the bushing wears or fails what happens, the pump starts leaking. Worst case the pulley is now running crooked and you could get a belt squeal.

Most likely, the noise you are hearing is the alternator or the water pump. To determine which one use a "mechanics stethoscope". This is a long thin screw driver with a plastic handle. Engine running place the tip of the screw driver near the bearing end of the alternator. Then lean your ear to the screw driver handle. Repeat this at the water pump. Take your time and be careful.

You can buy a tool that might be a little safer.
 

fast 99

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Assume this is a serpentine belt system? If so, applying anything to the belt will ruin it. Start with a new belt. Harbor Freight has cheap stethoscopes. Check for bad bearings. Serp systems can't handle any pully misalignment. Make sure the PS pully is nearly flush with end of shaft.
 

Maknwine

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Assume this is a serpentine belt system? If so, applying anything to the belt will ruin it. Start with a new belt. Harbor Freight has cheap stethoscopes. Check for bad bearings. Serp systems can't handle any pully misalignment. Make sure the PS pully is nearly flush with end of shaft.
I went thru an issue with my S10 serpentine belt. It didn't start right after replacing the PS pump but I was putting other parts on truck that had worn out also. Anyway, I failed to drive the pulley all the way on the shaft and the belt was slightly misaligned. Finally figured it out and no more chirping.
 

Sgt Gus

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Assume this is a serpentine belt system? If so, applying anything to the belt will ruin it. Start with a new belt. Harbor Freight has cheap stethoscopes. Check for bad bearings. Serp systems can't handle any pully misalignment. Make sure the PS pully is nearly flush with end of shaft.
Please take a picture of you using the stethoscope on your truck. That would make a great pic.
 

fast 99

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Please take a picture of you using the stethoscope on your truck. That would make a great pic.
What? Have used them for years to identify noises from wheel bearings to noisy oil pumps and exhaust leaks. Not exactly sure what you mean by that comment.
 

Snoots

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fast 99 Brian, MD
 

Sgt Gus

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Comment wasn't meant to be insulting sir. I find it interesting the things we come up with to diagnose things. But I am very visual and seeing someone bending over the vehicle whipping out a stethoscope, well makes me smile.
 

Sgt Gus

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Most likely, the noise you are hearing is the alternator or the water pump. To determine which one use a "mechanics stethoscope". This is a long thin screw driver with a plastic handle.
Ahhhh, see. I had a much different visualization, LOL
 

fast 99

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Comment wasn't meant to be insulting sir. I find it interesting the things we come up with to diagnose things. But I am very visual and seeing someone bending over the vehicle whipping out a stethoscope, well makes me smile.
Ok just seemed like an odd comment, were good.
Have used SC for at least 10 years. It's a very useful tool and cheap.
 

Camar068

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Is it constant or does it chirp? If it chirps I'd look at belt alignment
 

75gmck25

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The stethoscope I have has a tube on the end, and a couple extensions.So far I have only used it to track down a tick from one lifter. Turned out the adjusting nut had loosened.
 

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