reverse engineering a/c
Thread Starter
Le Mans Master
Joined: Aug 2010
Posts: 9,272
Likes: 17
reverse engineering a/c
you folks that have converted to r134 and arent happy with it .
possibly have access to r12 or a variant
drain the r134
drain the r134 oil
change the drier
install r12 oil
pull a vacum
re-install r12
hope this helps
possibly have access to r12 or a variant
drain the r134
drain the r134 oil
change the drier
install r12 oil
pull a vacum
re-install r12
hope this helps
Instructor
Joined: Jun 2010
Posts: 165
Likes: 0
From: concord ohio
just had mine done yesterday. I found a NOS C6 compressor on Ebay for $125, bought new low pressure hose set, new office tube, 4 cans of R-12 from Ebay, and an o-ring set. The shop charged me $150.00 to flush the system, install the new parts and add 3 pounds of R-12. Ice cold air!!! I did the change over to the C4 blower when the system was apart, big difference is air volume. It was 92 degrees yesterday and I had to turn the fan down 2 clicks.
Race Director
Joined: Jan 2000
Posts: 12,399
Likes: 247
From: San Jose CA
FWIW, the tools that shops typically use to plumb to R12 have different adapters than R134a. A "true" R134a conversion will have these adapters attached. I believe in some cases they're self tapping and may damage the original connector.
(I can't remember where the ports are on the 78 off the top of my head - one of the fittings is typically on the accumulator/drier, so oldalaskaman's post may cover that one.)
(I can't remember where the ports are on the 78 off the top of my head - one of the fittings is typically on the accumulator/drier, so oldalaskaman's post may cover that one.)
Safety Car
Joined: Sep 1999
Posts: 4,930
Likes: 11
From: AnyTown NJ
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
Did it 2 years ago....I like the idea of swapping out the blower fan which in my opinion is the weak link in the C3 HVAC system....other than allowing hot coolant to the heater core all the time. 
Race Director
Joined: Jan 2000
Posts: 12,399
Likes: 247
From: San Jose CA
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Race Director
Joined: Mar 2006
Posts: 14,112
Likes: 28
From: Florida
It's illegal to go back to 12, once you have changed from it and also illegal to use the wrong fittings with the incorrect refrigerants.
I doubt a reputable shop would do it for you so you could save a couple bucks. Epa fines are pretty steep.
I doubt a reputable shop would do it for you so you could save a couple bucks. Epa fines are pretty steep.
Thread Starter
Le Mans Master
Joined: Aug 2010
Posts: 9,272
Likes: 17
havent done mine ...yet, but there are threads on here for upgrading to the C4 version
toward the bottom of this is a pic of the C4 fan spacer
http://api.viglink.com/api/click?for...13447996247663
toward the bottom of this is a pic of the C4 fan spacer
http://api.viglink.com/api/click?for...13447996247663
Last edited by oldalaskaman; Aug 12, 2012 at 03:27 PM.