Please help diagnose AC problem...

[Quakecom]

Hey everybody,

my AC has gone south and wont produce any cold air anymore. This isnt much of a problem right now since its about -5 degrees Celsius over here in Germany right now, but it will be one in a couple of months when it gets hot.

It seems that the AC systems is empty. I have tried recharging it using one of those ready-to-use recharging kits. There is a pressure gauge on it that tells you when there is enough in the AC systems. The problem is that the freon gas (?) leaves the system as fast as I can put in, meaning its leaking somewhere.

Is there any way I can try to diagnose myself where the leak is? Are there any parts of the AC system that are prone to failure (or leaks) ?

Thank you in advance for any help or information...

Take care

Quakecom

 

[Brock94]

The service port valves often leak, but it sounds like you have something leaking faster. The hoses and the hose ends (connectors) are likely places to leak. Another common area for leaks is the accumulator/drier (the thing that moisture collects on when you're running the a/c on a hot day)-- because of all the moisture, it tends to rust out. The condenser could leak-- especially if you took a hit with a stone, etc.

Look for places where oil might be leaking out of the system too. Pros would use dye and a u/v light or an electronic refrigerant "sniffer" to find a leak that wasn't obvious.

Honestly, you've got to get a few special tools and take the time to learn about how a/c systems work and how to properly repair them if your system has more than a really slow leak (one that you can just refill every season). Refrigerant can be dangerous, you have to be sure the lubricant didn't leak out of the system, if the system has been open, you should replace the accumulator/drier, once repaired, you'll need to pull a vaccuum on the system to evacuate any air that got into it, it's illegal (at least in the U.S.) and bad for the environment to release refrigerant into the air, etc., etc.

Since your refill kit obviously didn't work, you may need to take the car to a pro. (Not to discourage you if your really motivated-- a DIYer can do this stuff with the right tools and some basic knowledge.)

There are some really good threads about A/c repair on this site if you search. Also, on www.diynet.com if you follow links to a TV program called "Weekend Mechanic", they have a really good step by step summary (with pictures) of a show in which they repaired an a/c system.

 

[Eneurb]

Condensors and accumulators are pretty bad for leaks, but with out a leak tester, or atleast dye it's had to tell. Accumulators rust out under the foam insulation, and condensors leak on the bottom corners.

 

[RiverRat]

The problem is that the freon gas (?) leaves the system as fast as I can put in

Quakecom

You should be able to visually locate this leak. Put a small amount of R134/R12 or what ever you use into the a/c system with the engine off and you should be able to see where it's leaking. Big leaks are easy to locate. It would still be a good idea to have your vehicle checked out by a certified a/c shop.

The a/c pros here are great

 

[Glacier991]

at -5 degrees the gas pressure of refrigerant is too low to operate the system. (6 PSI R-12 and 4 PSI for 134a). The low pressure cutout won't let the system run below about 25 psi.