PeachParts Mercedes-Benz Forum - View Single Post - I used the wrong can of 134-A too much oil

jay_bob · #3 05-23-2016, 12:45 PM

Yup. Just been through this on my 210 after the compressor nuked itself.

At least you have a 123, with serial flow evaporator and condenser, which can be flushed. Later models went to a parallel flow type condenser and evaporator, which can not be flushed. You can get to the evaporator coil ends at the expansion valve under the dash without having to tear the whole dash apart. Just be careful, the flush will spray everywhere...set up a good containment.

You should replace the following parts on principle, they are inexpensive:
Receiver dryer and sensors
Expansion valve

While you are in there plan on replacing every o-ring in the system (HF has a universal green o-ring kit for $10). And when you have it back together, be sure to pressure test with dry gas before pulling vacuum. If you have a leak and you just pull vacuum then it will draw in moisture and ruin your brand new dryer.

If your system was working well except it had a slow leak, chances are good you will find the source of the leak in your work on the o-rings. Unless the compressor has a shaft seal or (in the case of an R4) case half o-ring has blown. But usually those are catastrophic and it won't hold charge at all.

If you find out the compressor is bad I highly recommend the Roll Guy Sanden retrofit. I have been there before, don't waste your money on a replacement R4, horrible excuse for a compressor.