A relatively brand new A/C drive belt failed on me this afternoon. There was a bit of squealing, a lot of smoke and then everything got better. I pulled over into the nearest garage and got the mechanic to confirm that it was the A/C belt that had failed, and nothing critical to the engine operation. But now I'm wondering if that belt runs more than just the A/C compressor, does anyone know? My father-in-law thought it might also run the water pump. I'll have to download and print off Noel spec sheets, but I'd like some further confirmation that driving without this belt is going to be OK.
The next question is why did it fail? The belt was only 3 months old. I thought the compressor might have seized, but it still rotates when I try to turn it by hand. I'm on vacation in Vancouver, but I'll try and get some pictures of it if I can figure out how to download them to my in-laws PC
The compressor will spin freely until the AC is turned on, then a electric clutch will engage the compressor pump. You would have to make sure the clutch engages then try spinning the pump.
Could also be poor alignment of the belt, that should be adjustable.
AC compressor is on its own, no other accessories.
4 options.
1: Belt put on crooked, cut itself apart.(hopefully, but if the first belt failed the same way, not likely)
2: Tensioner pulley seized . Find the pulley, see if it spins freely. If not, you need a new one.
3: AC compressor clutch bearing seized. Spin the part where the belt goes on the AC compressor. (I suspect this is what you were spinning by hand and it felt ok) IF it spins freely, go to step 4.
4: COmpressor seized. Definately worst case scenario. Put your hand flat on the front of the compressor, try and spin the front part. It should turn with a slight amount of resistance but the part that the belt attaches to should remain still.
If step 3 is a failure, you will need to replace the clutch assy, and most likely the whole compressor as well since you probably wont be able to separate them.
If step 4 is a failure, you will need a new compressor, clutch, receiver dryer (if the compressor has disintegrated internally), and have the ac lines flushed (again, if the compressor has come apart inside)
I am curious what kind of mechanic you took it to if he couldn't even look at it and tell you what failed. Would have taken only about 30 seconds of his time.
And yes, it is safe to drive, just make sure you have all the broken bits of the belt out of there so they don't get into the other accessories.