Anyone converted a 126 chassis from R12 to R134 down in the hot south? I
am in Texas, and it gets very hot. I have a leak that was about a pound
a year. Now it needs more than a pound of r12. My mechanic wants to
convert it to R134, changing the dryer, for 600.00 dollars. Seems a bit
high to me, but I am more concerned that the cooling will not be
adequate in the Texas heat. The leak might be in the evaporator. I don't
want to pull the dash. Is there a sealant kit for R12 systems? Any
advice will be appreciated. Thanks, Ken
Do a Google on sealants. I have seen them for R-134 so I wouldn't be
surprised if they have one for R-12. Really be sure you find all the leaks
before conversion. Use a dye and black light, looking everywhere. You'll
need a freon sniffer for the evaporator. But it could also be an expansion
valve connection leak since it's up there too. The mechanic can get close to
the Ex valve to see if it's the cause. Compressor seals and suction hose are
two other places to focus. If you do have an evaporator leak and can't find
a sealant, ship the car to Maine and sell it. I think you'll find replacing
that item incredibly expensive--mostly labor.
As for the R-134 refrigerant, it works fine in my '86 420SEL in sticky hot
Georgia. However you need to be sure that you replace not only the dryer but
also the two pressure switches that engage the compressor clutch. I think
many people who are not happy with R-134 cooling forgot to have them changed
and the AC is not operating withing the design characteristics of R-134
In any case it would be good to find the leak. To the horror of many
'experts' I have converted a Pontiac and Volvo using the cheap kits
from Kmart. No replacement of dryers, switches or even oil was done.
Worked wonderful for the 3 years in both cars until the Pontiac was
traded in and the Volvo was laid to rest.
I found the sealant.
If you do have an evaporator leak and can't find
:-) My thoughts exactly! If it is the evaporator and it is too large
to seal, I am screwed. I am not going to pull the dash.
Great, my kind of weather! :-)
However you need to be sure that you replace not only the dryer but
Good advise. I found another mechanic that changed his own 85 500SEL to
R-134 and he says his works fine. And he is going to do it for 150.00.
The system had gone empty. He placed the ester oil in it, changed the
fittings, and put the vacuum on it over night. Today we are to find the
leak and fix it. Then recharge with R-134. Fingers crossed.
That's very high! Go to a place that can inject fluorescein into your system
after it is drained. It will reveal any leak when exposed to UV light. You
will nedd a new receiver/drier-standard procedure when converting. R134 is
dirt cheap and the required change of cap colors included won't cost
anywhere near $600! P.
I have done a 1986 420SEL and stayin' cool in GA. Be sure you have a good
mechanic do the job and ask to see the old pressure switches along with the
usual parts. Also I suggest you have a dye test done and fix any leaks
(compressor seals or low side suction hose).
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