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Discussion Starter · #1 · (Edited)
I will be replacing my air con compressor as it is squealing every now and then.
There is no leak in the system that I know of and it works fine (but takes a while to cool the car down in Australian summer).
Last regas was 10 years ago.

Should I also replace these parts?
part #50 = 1H0 820 679 A expansion valve

part #17 = 1J0 959 126 pressure switch

part #2 = 1J0 820 191 A dryer
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I'm asking because:
1. access in a V6 is tight
2. don't want to re-gas twice
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If it's squealing, it might be that the clutch on the end of it is slipping, and the compressor is internally okay. This could either be because the clutch is worn down, the coil is weak, or the coil is not being supplied enough voltage.

Replacement clutch assemblies can be found online, either brand new, or you can get a second hand compressor and swap the assembly over. This includes a coil. Lack of voltage to the coil is caused by a bad FCM. Worth verifying the voltage, under load, to the coil is around 12V, prior to replacing anything. Coil should read around 4 ohms of resistance, unplugged.

To replace the clutch assembly: Remove aux belt, remove 13mm nut from the front of the compressor, slide off clutch plate, remove circlip for pulley, remove pulley, remove circlip for coil, remove coil. And re-assembly is just the opposite, add a bit of thread locker to the 13mm nut too.

Any of the above removes the need to vacuum down and then recharge the AC system.

If you do go ahead with it anyway, pressure switch should be okay, as should expansion valve, so I wouldn't replace those. Dryer replacement will have the benefit of cooler AC, quicker, as the old dryer will have absorbed a lot of moisture over the years - replacements are cheap, but replace o-rings on the connections going to it at the same time.
 

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Discussion Starter · #3 ·
Cheers for that, I tried removing the clutch on my donor V5. It was a huge struggle and even more awkward to get it back on. As it needs a regas, decided to replace compressor. Its seen a lot of hot Brisbane summers in almost 20 years. Will do the dryer.
 

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Discussion Starter · #4 ·
Wanted confirmation that my plan is feasible before I approach Air Con specialist.

Having read the explanation, and someone else's journey, I propose to:

Have Air Con shop evacuate the 134a refrigerant.

I will replace compressor, drier and O rings myself.

Leave all oil in new compressor that it came with.

Return to Air Con shop to fully evacuate the system, vacuum down, adjust oil volume and regas.
 
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