B6 Magnetic pulley

Hi All.

Just had my air con re-gassed in a hope it would fix my none working air con but no joy. I've tested the live feed to the compressor and that switches on and off with the switch. I phoned TPS just to get a price on a replacement compressor (worth a laugh) and it is £750 plus vat LOL! The guy from TPS said it was more likely to be the magnetic pulley (£135) rather than the compressor. Has anyone any experience of replacing the pulley, is it fairly straight forward or is there any way to repair the original one?

Thanks
Chris

Yes I've checked the power to the clutch and it has power and it switches on and off with the button in the car and the clutch moves freely within the pulley but the clutch doesn't engage when the air con is switched on.

palfy86 said:

chris mines not worked for over a year now (not good i know) had mine diagnosed as the electronic solenoid/switch on the compressor itself not engaging, these aren't available as a seperate item at the moment so for me its a new compressor, nissens or hella i havent decided yet lol.

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Sounds like "solenoid/switch" is the same as the magnetic pulley mentioned by TPS. They quoted me for just the pulley, £135.
Think I'm going to give it a try before I try and get a new compressor. I'll try and find someone to plug in VCDS to check if there are any sensor faults first though.

Well yesterday I did a little more digging around and found that inside the clutch/pulley there were some broken up bits of rubber which were some sort of cush/damper for the pulley. I managed to pull 3 or 4 bits of this rubber out if the pulley so I've ordered a replacement pulley from TPS. It should be here today and I'll update when it arrives.

adamss24 said:

If that does not fix it then the solution is to find a compatible AC compressor, let me know if you need one, breaking a few cars so i have 3 or 4 compressors at the garage....

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Thanks Chris. BTW the S4 brakes work a treat and look great behind the wheels.

Got the new pulley today and when comparing the new pulley and the old pulley it was blatantly obvious that the old pulley was knackered. The pulley is in 2 pieces, the main pulley (outer) that the belt drives, and the inner pulley which pushes in from the front. The inner part of my pulley was completely missing (sheared off) hence why the compressor wasn't being driven by the belt. The pulley on my compressor isn't like the majority of aircon pulleys which the pulley is a electromagnetic clutch, on my compressor the pulley is just a dampener pulley (very similar to a motorcycle sprocket cush drive). It has rubber blocks fitted into the outer pulley and the inner pulley fits into the rubber blocks. The electromagnetic switch/clutch is housed within the compressor.
According to the guy from TPS the pulleys are quite a common failure and they sell plenty so before you fork out for a new/secondhand compressor on your B6 just make sure the pulley is intact.

Here is the remains of my original pulley

Those slots inside the pulley should have rubber blocks inside and the small aluminium piece is all that's left of the inner plate.