Posted on Jun 22, 2009

AC belt squeals under load.

AC runs fine, but the AC belt squeals if I am driving and step on the gas, ie increased load, or if sitting at a stop light and the AC kicks in to put out more, because of idle. If at fast idle, there usually is not a problem.

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Ron Vrba

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Posted on Jun 22, 2009

Ron Vrba

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Joined: Jun 22, 2009

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The 1st thing I'd do is to get a spray bottle with water in it and spray the belt driving the compressor while the A/C is running and cycling on and off. If this quiets the squeal, it's probably too little belt tension. Check the belt driving the A/C compressor pump for sufficient tension. Do this by locating the longest part of the belt not touching a pulley. Depress the belt at the midpoint of this open span with moderate thumb pressure. It should not deflect more than about 1/2 inch. If it does deflect more, you'll need to increase the belt tension by putting more pressure on the belt route. Usually, there's some sort of bolt or machine screw on the compressor to do this. Increase the belt tension to the desired deflection. Warning - too much tension will cause premature failure of the compressor bearing!
No improvement to the squealing requires more help than I can provide you with.

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