Tampa 928s

Do you need to change the Expansion Valve when converting from R-12 to R-134. My friend is getting his changed now and the shop is saying it calls for the same expansion valve, is that true?

dprantl

You don't HAVE to, but I would do it. It's <$50, they can fail and replacing them requires an evacuation of the system. And you will be disconnecting it anyway to replace the o-rings. They are replacing all the o-rings... right?

Dan
'91 928GT S/C 475hp/460lb.ft

Tampa 928s

Of course not, pay me now or pay me later, do they ever listen!
I gave up working on this car because of this type of stuff so when it leaks in a few weeks I'll say told you so.

dprantl

Ha, I bet there will be no flushing of the mineral oil either.

Just another +1 to the people who think an R134A conversion sucks, not knowing or admitting to themselves it's because they didn't have it done right.

Dan
'91 928GT S/C 475hp/460lb.ft

Tampa 928s

I did talk to the shop they said they flushed it and added ester oil We shall see or feel as the case maybe. Don't need no stinking seals !!

the flyin' scotsman

To get my converted system to work perfectly I replaced the compressor (rebuilt Porsche), the main a/c hoses, the rxr/drier and the expansion valve. All associated O-rings were replaced with the green ones, system was flushed and Ester oil added.

Mongo

I've heard this is a bad idea. On mine, the compressor, receiver/dryer, and expansion valve are all shot to sh*t. Would it still be worth keeping to R-12 or do I have enough components to replace there to goto R134?

Tampa 928s

He just called the shop put in 2.5 Lbs of 134 on an 82 this should be 1050 grams less 20% or about 1 lb 13 oz is this correct. Can't wait till the system blows up!

dprantl

LOL @ 2.5 lbs. The system should have 860 grams of R134A if it does not have rear A/C. That's 29 oz or 1lb 13 oz like you said.

Dan
'91 928GT S/C 475hp/460lb.ft

Bill51sdr

R-12. It's colder, the system is under less pressure & there's still plenty of R-12 around.

Yes, I will catch some grief from the pro 134 crowd.

SeanR

Can we say overfill? Change the expansion valve and don't convert to 134

Tampa 928s

TOOOO LATE: He came over for me to look at it, the high pressure valve is leaking, so maybe it will be down to the correct pressure in a while. He never listens to me, it has a one year warranty for $775.00 includes rebuilt compressor, he will need it. The window on the R/D still had his sticker over it I asked if you could see bubbles he said no, humm wonder why. I feel bad I did not do this job myself, but I have done enough on this car and don't want to live with it the rest of my life.

ZEUS+

If the expansion valve works, there is no need to replace it. It works by temperature, not refrigerant type. Hopefully the comp shaft seal isnt leaking now. Cant use the r/d window with 134, will always look cloudy. That place is killing his car.

Tampa 928s

I know, from what I have read if you can see a few bubbles after the conversion its correctly filled. Either way, the R/D valve is leaking and will need to be repaired so by the time it leaks out he will be ready to get the correct charge in it.

Sailmed

I have converted every 928, pickem up truck, and even the freezer in the boat to 134a - and they will freeze you out!
PROPERLY done - they work great. I have yet to change the TEV.