I just bought all the fitting for 134 for my 69 rivi an new drier, an expansion valve, got every thing hooked up but someone was telling me i need to change the schrader valve to a 134 bypass that the r1 on will not work is this correct.
Depending on the conversion fittings you have, you might have to remove the old schrader valves. Some are made to work with the old valves, some aren't. If the conversion fittings have schrader valves in them, remove the old ones. To get good performance and reliability from your conversion you need to drain and oil flush the compressor sump, solvent flush the rest of the system and adjust the POA valve to work with R134a. (adjusting the POA makes all the difference in the world!) It's also cheap insurance to replace all of the 41 year old seals in the lines. If you compressor is old, the shaft seal is highly suspect. It can be replaced with a modern neoprene seal to get rid of the oil slinging common to the old ceramic seal.
If I was going to do this again I wouldn't switch to R134a fittings. That way you can still use R12/22 guages and hoses.
"Legally" you have to change the fittings, but... o No: The good thing about the R134a quick connects is that you don't lose refrigerant when connecting and disconnecting the hoses. The hose seals last much longer too. It's a much better setup all around.
