Q&A: Converting a Navajo’s air conditioner and creating a fuel dipstick for a ComancheWritten by Steve Ells
Q: Hi Steve,
I am planning to buy a nice Piper PA-31-310 Navajo. I’ve got my eye on one that’s based locally and I really like this airplane. It does burn some fuel, but boy is it a good performer.
During the pre-purchase inspection the mechanic told me that he thinks I should upgrade the air conditioner to the R-134 type[H1] . I asked why, since the AC seemed to be blowing lots of cold air during the test flight.
He said that the system was old and that he suspected it had been recharged just prior to the test flight to cover up the fact that it was old. He pointed out a couple of hoses that do look pretty tired.
I know that the old R-12 refrigerant has been outlawed by the EPA and that the new stuff is R-134a. Will R-134a work in the R-12 system?
How about charging the system with some of the other stuff that’s advertised as an R-12 replacement? If not, what other options do I have?