PeachParts Mercedes-Benz Forum - View Single Post - How do I know what refrigerant is in my system?

JHZR2 · #13 06-30-2009, 11:06 PM

+1 I do not want to take any chances.

I know there is still a charge - the compressor engages.

I've heard that HC-based R12 refrigerants use a quick-connect. Unsure if HC refrigerants pass through non-barrier hoses like 134a...

I have an appointment for Thursday AM to get it sniffed and see what is in there.

If Im lucky enough to see only R12 (could HC refrigerants not be detected, should I worry about this?), Ill have the system leak checked, evacuated, vacuum pulled on it, then refilled by weight. Ill ask them to replace the schrader cores and add 1/2-1oz of oil to the system, then add the correct mass of R12.

If they see R134a, then Ill immediately have the system evacuated. Since I plan to use the car for the weekend, Ill drive without AC, and then plan to take it back in for R/D, full flush-out, re-oil and refill with R12.

It may have been a botched R134a job - certainly not a retrofit... Im leaning towards it being an HC or freeze-12 or similar job, which worked well enough, and worked for about a year (with still enough pressure now to engage the compressor). Im hoping that it was HC and that the HC diffused out... and so R12 will work OK.

Wish me luck!