r12 - r134 conversion

[bfrey003]

so my mechanic told me my ac compressor went bad (it stopped working and one of the bolt appendages broke). i bought a new one and took it up to him and a day later he told me that it's still on the r12 system and that they cant do the conversion. he gives me the number to another shop where they told me the conversion would be about $1000. Is that normal?

also, do i have to do a full conversion? i really dont care about the ac but i need the new compressor in there so the alternator will run since it's all in the belt line.

One the plus side, he installed a new starter for me for free

[Briano1234]

Gee. See if there is any Gas left in the system at all? How? Well take the cap off the schrader valve on the strut tower and hmmmm press it with a phillips screw driver...
Oh, there is gas? Funny by pressing that valve it all escapes, as well as pressing the one on the condensor near the power steering valve. Then take it to the other shop and say, that all the gas has Leaked out because of the bad compressor. Eco-Nazi's take all the fun out of driving.

See my thread on how I change out a water pump, as it tells / shows you how to remove the compressor if you have a Sanden style....
viewtopic.php?f=27&t=2178

Then you can replace the compressor and have it evaced/charged.... or
You can buy or rent a pump and manifold set then evac and charge it yourself and save a ton of monies.
I would also buy a new drier for it, that is under the windshield washer jug.

3 cans of R134a is all you need, plus about 6 oz of oil.

I did a how I converted mine to 134A after changing the condensor thread...

(Since I originally wrote this, I have bought a manifold set and pump from harborfreight, with a 20 percent off coupon, and the pump on sale I got it for about 70 bucks. Since I bought it a few years ago, I have used it about 7 times, and really recommend that as the way to do it right.)


As it is getting close to the time when folks need a/c work....here is a running dialogue that I had with Thomas Covenant, on a different forum.

Thomas it was really rather easy. I took the receiver/dryer out,
poured out the oil in it then I took the compressor off and poured
the oil out of it.

Filled the compressor with the proper quantity of pag oil, Replaced
all the o-rings that I broke the connectors on with nitrite rings.

Replaced the Condenser (salvaged from a wrecking yard, at 15 bucks
easier to take.

Then (here is where the nay-sayers are going to balk.) Placed on
the converter fittings and Placed one can of freon (r134a) in the
car.

Then I went to the high pressure side of the condenser (engine not
running yet) and loosed the fitting till freon rushed out, for 10 seconds
then re-tightened. ( be careful not to get frost bite ). Wait 2 minutes for the
system to equalize. I started thecar, on the suction side placed a o-ring sealer in it,
then added a can or 134a. Turned on the a/c and it engaged the
compressor and sucked that can dry. I then topped it off with the
proper amount of r134a that it used for r12. Now the nay sayers
will tell you to draw vacuum, but I am a cheap bastard ( cost
effective) and was taught shade tree a/c from a friend. Bleeding
the high pressure side forces the high side to have hi pressure,
the low suction side then has low pressure, and you have then purged
all the lines of air...cool huh? So that when you kick it on, it
will suck in that can of freon like it should.....

Buying the kits will get you half the way there, but on my eagle I
had to use a high pressure adapter on the low side (only fitting
that would work) then buy a manifold kit and it comes with an
adapter and a gauge that connects to the High connector and then
allows you to place a can of Freon on it. The Two biggest problems
that I have seen happen with those kits, is that the compressor gets
too much oil. Draining the oil out of the Dryer, and the Compressor
and re-filling it with the proper amount of Pag oil is paramount to
getting a quiet and smooth running operation. I never buy the oil
charge, as I have filled the thing with the correct amount. Dupont
makes a Yellow can of leak detector, that you can see with uv
light. Most of the Cars I converted were because of a leaking
compressor 2 holed condenser and a compressor that locked up.

now for the ECO-Nazi's You should have your freon r12 sucked out by
a quality shop...as it has been known to damage the O-Zone ( my Ass)
layer. Like cow Flatuance, Mt Penetobo, Mt St. Helens didn't
either, but I didn't see the Eco-Nazi's fining Mother Nature. But
if your system is devoid of r12 by a broken condenser, loose fitting
(wink wink)then there is no problem with inserting the r134a instead
of r12, just remember that you need to drain all the oil out you
can. Run the a/c at max and if the lines don't sweat after a few
minutes then you need more freon, the other side of the coin is that
when the line starts sweating, your system has enough freon to do
the job. But personally I prefer the weighted method.

You will get all kinds of nay sayers and God-who-knows-it-alls, but
these are the steps that I followed, and they worked for me.




The Low pressure side where I put the convertor on.



The receiver dryer, that I removed to drain all the oil.



Closeup of the low pressure side





pic of the High pressure side I bleed the 134a on it is to the front of the radiator hose nipple.....



pressure test

low side 15 to 30
High side 150-270 up to 84
high side 150-210 from 85 up to 93

Oil
r209 compressor 79-81 10.0
sc209 compressor 79-81 8.0
Sankyo compressor 79-81 6.0

82-84
sankyo/sanden 10.0
york sc-209 8.0

85-89 6.0

90-93 4.8

Refridgerant

80 2.06 pounds
81-84 2.0
85-91 2.5
92-93 2.06

I would assume that 92's lower poundage is due to r134 being installed.....but I can't verify that for a fact.

I went by the weight of the can for the total poundage that I was putting in then verified it by pressure/sweating test.