Belt Squeal at Startup

Platonic Solid

Founding Member
May 29, 2002
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CT-USA
Every time I start the 73 Mach1 351C I get a loud high pitched belt squeal. It only happens for the few seconds when the engine fires up. I’m calling it belt squeal since I can’t think of anything else that sounds like that. The belts are new and tight. The steering pump and alternator are new. Could it be the water pump (which seems to work just fine)?
 
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Visually the pulley alignment looks fine, but since looks can be deceiving I took a carpenters square and held it flat against the crankshaft pulley and measured the distance to the belts and it all checks out fine. I only have 2 belts: 1 for the alt. and 1 for fan & steering pump. The AC compressor isn’t installed so that belt isn’t there.
The crank shaft pulley channels do look glazed, but I assume that’s normal. I’ve never used belt dressing, as I always thought that was more of a temporary band-aid for older belts.
 
Are there any indications there is a pump failure (overheating, steering problems..etc)?

Have you tried spinning the water pump by hand to make sure the belts are tight enough? I know you said they were tight, but common sense says the belt squeal issue is coming from a loose belt. Take the alternator belt off to test the tightness of the PS belt, then take the PS off to test the alternator. My point being that you may not be able to tell that one belt is loose because the other is tight.

I hope you get it figured out.
 
I took the power steering/water pump belt off and started the car = no squeal
Put the power steer/water pump belt back on, but looser than before = very tiny, practically un-noticable cherp.
So apparently I had that belt on too tight. Live and learn.
Thank s for the input.