Less than 2500 hours on machine and ac cooling great. Had an intermittent squeal that recently started and before I could check it the air conditioning belt broke. The compressor turned easily and the idler pulley seemed fine so I replaced belt and tightened. Ran fine about 8 hours over a few days(notin a row) then squeal noise started again. Checked belt, seemed tight, ran a few more minutes and belt broke again. Not sure what to do or check next. Any advice is appreciated!
Is compressor on it’s own belt circuit , it sounds like one accessories is seizing up
Yes compressor and tension idler pulley only on this belt.
So can the compressor turn easily while it’s cool and seize up after it’s ran some time? And continue to cool properly? It’s cooling as it should until the belt breaks.
Sounds to me like the compressor is jamming up. Pully turns freely until clutch engagesthen compressor starts turning .could be jamming intermittently stopping the pully making the squeal then break belt
Just a thought... If there is moisture or incompatible oil in the system, you could be having a hydro lock issue. Better a belt than a compressor. Anybody add oil to the system ? If moisture, you'll have to evacuate the system and pull a deep and sustained vacuum. I used a hair dryer on the a/c parts & hoses to speed up getting moisture out.
Update, I put another belt on the ac and a friend came over w gauges. Had 20 lbs pressure on low side and 250 on high side at idle speed. Rev up to 1900 rpm and low side drops to 10 and high side increases to about 300. It cools blowing 45 degrees temp at vents. Anyone know what correct pressures should be..? ac clutch turns freely. But something is causing it to seize up and break the belt after it’s fun for a while.
Remove the idler pulley and rotate it in your hand. Smooth and fluid it should feel. Most of mine take a 620S bearing. It can be pressed in/ out, so as to not have to buy the whole pulley. I have the same setup on my 3064 and 3066 powered caterpillar machines. I'd bet my lunch money on the idler pulley bearing. As for pressures, those are good numbers.
Thanks for the reply. I’m gonna replace the idler pulley and see how it does as that is the easiest and least costly part to see if that eliminates the problem.