1991 PZJ77 A/C question

[tohox]

Hi,

Wondering how I can tell if the refrigerant in my truck's A/C has been changed to 134A or if it still uses the original R12. My understanding is that the connectors and the drier would have been changed if that was the case but it looks like the A/C pump still has the original R12 connectors on it and I see no additional adapters. Can anyone confirm? Thanks!

 

[FJ73Texas]

My PZJ70 still has R12 and the same caps as well. If that helps any.

 

[FJBen]

My BJ74 has the same caps and shrader valves. It's possible they could have put the adapters on, filled it then took them back off, but that doesn't make much sense. Although sometime previous owners do really weird nonsensical things.

 

[jblueridge]

In USA, if a shop changes the refrigerant the tech must change the "ports" and put a label or notice sticker somewhere.
If a PO switched over, I am not sure how to know.

Do you see any flow in the sight glass when compressor is running?
Perhaps the different types of lube oil mixed with refrigerant are color-coded.

 

[CharlesHS]

Those fittings are for use with R12, the drier and O rings should be changed when replacing the refrigerant and the oil used with R134a is different than with R12.