My First Air Conditioning Repair

[Maddog]

Well I just got certified to buy R12 and now I have an 82 240D to fix. The air conditioning does not work due to low freon. I know that there is a leak, because we refill the system every year and it works fine. Since this is my first time, I was wondering if someone could run me through the process of charging the car.

I am prefectly williing to go out and spend the $70 on gauges and possibly some money to buy a vacuum pump. I have 3 cars that run on R12 and I think its finally time for me to get my hands dirty with A/C.

What tools do I need to charge up a system and what tools to do I need to evacuate a system and then recharge it?

What tools do I need to test for leaks and how do you go about doing that?

Thanks for any help!!!

[Kestas]

You may want to read a thread I started a week ago about UV dye to detect leaks:

Where can I get fluorescent dye for a/c system?
There's mention that a kit is available at WalMart that includes dye and a light. If you can't get it there, you're sure to get it at acsource.com and ackits.com.

For tools, you'll need manifold gauges and a vacuum pump. Try eBay for gauges, a lot of mechanics are selling off their r12 manifold gauge set. After that it's all plumbing and hooking up the lines for evacuation and recharge. Ideally, you'd want to charge into the vacuum, that is, with valving as opposed to connecting and deconnecting lines.

You may want to lean on the guys at aircondition.com. There's a wealth of information there devoted entirely to automotive air conditioning.

If you only need to top off only once a year, you may not need any repair. I'm not sure where the line is drawn between normal leak and fast leak.

On a final note, have you considered charging with HC (hydrocarbon) refrigerants? It's worth considering if you plan on doing all your own a/c repair on your vehicles. It's a touchy subject though... VERY popular in Australia but looked down upon by many in the US.

[Maddog]

Thanks for the reply!!

When I apply vacuum to the system, do I need some kind of recovery system to work with?

The kit at Wal Mart contains goggles and light, not dye and light. UV dye for r134 systems is also available at Wal Mart. R12 UV dye is another matter. There is a kit available at ackits or acsource that has dye and an injector that you can use for R12 or R134 systems. That would be your best bet on an R12 system.

They also have an EXCELLENT book about auto a/c it is the Mastercool manual. I would strongly recommend that you get and study the manual before embaking on this task.

Not understanding these systems can not only result in damage to the system, but also personal injury.

Good luck,