Leak checking/refrigerants

[William Magliocco]

Went through this during the summer in my 1995 Passat.

I have a buddy who is a commercial HVAC whiz here in Atlanta.  He does not usually work on car systems.

Anyhow, I was able to catch him and here is what we did to find my system leaks:

1)  With an empty system, add about 4 to 8 ozs. of R-22.  Yes, R-22.  The probes service persons use work better with R-22 and R-12 than R-134a.

2)  Add nitrogen to about 250 psi system charge.

3) carefully run leak probe around system, including the center ducts in your dashboard.

4)  Adjust sensitivity of probe as needed.

This is an EPA approved method to find system leaks.

We found a 13 year old compressor with a shaft seal leak.

Oh yeah, get rid of ALL the old oil. Dump it out of the compressor, rinse the system with solvents.  Too much oil is a bad thing (ask me, I know).

When you are working with R-134a, the charge must be on the money.  R-12 is more forgiving of inaccurate doses of refrigerant.

Bill M.
EPA 609 licensed
Atlanta, GA