Automotive Air Conditioning Information Forum

Hello,
I have an old A5 to A6 replacement compressor. It has only about 10k miles on it. It’s the type with the bypass valve. The car sat not running for 45 years with pressure on the system. The system has been removed from the car for restoration. I want to rebuild this compressor, and restore the outside. It turns over smoothly and has remained sealed. This unit has an unusual flange compared to most A6 compressors, which is why I want to use it. Im going back with modern seals, but sticking with R12 refrigerant.
My question is, how should I go about cleaning out the old oil and getting it ready for a recharge?
Thanks for any advice,
Dave

If I were you, I would consider sending your A6 to an expert rebuilder for a complete interior and exterior restoration, which would include the correct decals. There are a few well known restorers out there whom I would trust to do a great job rebuilding your vintage compressor to like-new condition. I'm sure they would offer you a warranty, too. Well worth the money, I think.

The A6 with the flange for mounting in the A5 mount is not common at all. Hang on to that for sure. Flushing the oil from the compressor can be done without opening it.

https://www.autoacforum.com/messageview ... adid=12050

With an A6, you will need to drain & refill the sump when you use that process. Drain, refill, add oil to intake & spin. Then drain the sump and repeat.

As JIH pointed out, there are people that will do a 100 point restoration.

Rebuild the hot gas bypass valve. They are not hard to work on. Pay attention to the cam & pin. The last couple I did had worn spots on the cam that needed a little work with a stone, one had a notch worn in it from vibration.

Thanks Guys!
Both excellent replies and good food for thought.
I’ll let you know how I end up,
Thanks again,
Dave

Need proper equipment.
For roughly $80 plus coolant, most A/C companies will flush and replenish your system. It's either that or spend a lot of money on expensive equipment to do it properly.

Never seen any shop do a "proper" flush for $80.00.

I wouldn't understand if the engine would absorb water, but fluid will infiltrate the interior and land on the carpets. Additionally, because the drains are so little, it doesn't take much to clog them. I typically use a compressed air one every month to blast them out with the sun-roof drains. Possibly one of Audi's worst design decisions is this.

RoslynkScruggs wrote: ↑Tue Aug 30, 2022 6:24 am I wouldn't understand if the engine would absorb water, but fluid will infiltrate the interior and land on the carpets. Additionally, because the drains are so little, it doesn't take much to clog them. I typically use a compressed air one every month to blast them out with the sun-roof drains. Possibly one of Audi's worst design decisions is this.

Misunderstanding here. The A5 and A6 being discussed are A/C compressors, not Audi vehicle models.