I have found that any time the refrigerant has changed in anythng, a tag
is to be placed on the compressor to let know the next person to service
the AC what it is.
This is not law, it is consideration
This is same even with 134a.
It should be displayed on compressor.
The ony fitting changes are for 134.

Good Evening,

Fred

E-mail message

Well, yeah. Personally I don't think there's any real hazard to the
driver/owner from putting a propane/isobutane refrigerant in the system.
It can be hazardous to an A/C shop that doesn't know it's there, though.
David Brodbeck, N8SRE
'82 Diesel Westfalia
'94 Honda Civic Si

Fred