WARNING, the newer R134a coolant is incompatible with the ester based
lubricant used with the R12 freon. when updating older systems with new
R134a, the old oil needs to be COMPLETELY drained, flushed and replaced
with PAG oil. If not evacuated of the old lubircant, the R134a will
cause the ester oil to coagulate and lead to an eventual compressor
failure. Also, typically all the seals should be replaced as well as the
dryer/receiver. All this along with the normal charging procedures of
vacuuming down the system to remove all moisture before charging will
provide for a good retrofit. however, keep in mind that the R134a has a
lower heat transfer capacity than R12 which means an older system
retrofitted will have less cooling capacity than it did with R12.
Dave Yeung
Houston Region (where even MOD cars have A/C)
On Tue, 22 Jun 1999 09:45:49 -0600 "Mohler, Jeff"
<jeff.mohler@wilcom.com> writes:
>Ive had good luck on all my Toyotas, but removing the compressor and
>draining the oil from it in the sink...thats 90% of the oil, along
>with the
>replaced evaporator can (or is that a condensor..shit..I dunno).
>
>Been running great for 2 years on all 3 cars.
>
>-----Original Message-----
>From: Chuck Brazeau [mailto:cbrazeau@amaonline.com]
>Sent: Tuesday, June 22, 1999 10:40 AM
>To: Lindsay Wilson; autox@autox.team.net
>Subject: Re: Air conditioning?
>
>
>Lindsay,
>I ran into this problem at the end of summer last year with my '90 LX
>5.0
>(also ESP). I tried draining out the old R12 by letting it leak out
>the
>schrader valve (don't tell the EPA!), and just adding the new R134a
>stuff
>from a kit (adapters, 3 cans of R134a, and 1 can of oil), but I found
>out
>that the two types of freon are NOT compatible! It ended up locking
>up my
>AC compressor. I then discovered that in order to convert to the
>newer
>freon, you must have the old R12 COMPLETELY evacuated from your
>system.
>This means pulling it to a zero vacuum to get out all of the old freon
>and
>oils (professionally done). Then you can get the $30 kit from the
>parts
>store to convert and fill the dry system.
>
>I haven't had the money to replace my AC compressor yet (or the leaky
>line
>that caused it to need more freon in the first place), but I'm gonna
>have
>to - It's getting HOT in Texas!!! :-)
>
>Hope this helps!
>SeeYa!
>CB
>http://www.chuckbrazeau.com/
>
>----- Original Message -----
>From: Lindsay Wilson <lwilson1@ford.com>
>To: <autox@autox.team.net>
>Sent: Tuesday, June 22, 1999 10:21 AM
>Subject: Air conditioning?
>
>
>Advice on AC needed;
>
>I am working on an ESP project (1989 Ford Mustang LX 5.0)
>and now that the weather has gotten warm I find the AC is not
>working. I suspect that the coolant has all leaked out. I know
>I will need to update to the new type of coolant. Can I do this
>myself with a kit from a auto parts store, or should I take it to
>a professional (like a dealer?)
>
>Of course I could just remove the AC system, but I have to drive
>this car every day. :)
>
>Thanks,
>
>Lindsay
>
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