Hello, I have an 05 IC RE DT 466. Problem is the belt is squealing whenever the driver turns on the A/C. The belt is a serpentine belt and the only one on the engine. Driver reports there is no squeal once the A/C is off. Already changed the belt once and tested all the pulleys. Also changed the tensioner. Thought it might be the wrong belt but am using the same aftermarket one that my predecessors used. The A/C system is aftermarket as well. Any ideas?
Put the guages on it to make sure the pressures are within specs. If there is a block in the system the high pressure will be too high causing the compressor to over work.
Your belt is slipping. I would check your pressures as Ryan said. You could also try another brand, we use the Gates HD's, or it could be your belt's just a bit too long, not letting the tensioner apply full pressure. What belt is it and I'll see if I can find you a number for one that's just a bit shorter?
All A/C systems on buses are after market. There should be a tag on the bus somewhere that has the belt number on it. If not, call the company that made the system and they should be able to tell you what belt it has. I would say, as others here have, you are having issues with the system though.
Thanks for all the responses. The belt is a Napa 25-081189HD that is on it. Tried to fit the next size lower on the Napa belts and it would not go on Big Papa. Got in contact with TK and they are trying to find the belt as well. A/C system is working well. Pressures are normal. Took bus out on run with A/C off and the belt started to squeal. (Not that I don't trust the drivers. HA!) Thanks again for the advice!
From that part number it looks like NAPA belts are made by Gates whos number for that belt is K081189HD. IT is 119.5" long, next one down is K081177HD at 118.25" long.
How much of the compressor clutch pulley does the belt contact? Look at it like a clock. Does it touch 6 hours of the pulley? 8 hours?