Air conditioning refit: R12 -> R-134a

[mongoose]

No big deal, but I can't seem to locate the low side AC service fitting on my 90 TGP. (High side located between the battery and the turbo). Can someone clue me in?

Thanks guys :)

Chuck

[sleeperred90tgp]

There both where you were looking only the high side is about 6'' lower and to the rear. Red cap I think. :Low side is higher and to the front. Blue I think.

Jud

[mongoose]

oh ok, guess I didn't look hard enough :)

Thanks!

[no1kicker]

What's a good way to do this?  I saw a $30 kit at pep boys that includes the 134 and oil, and fittings to convert.

[mfewtrail]

Greg, those "retrofits" aren't exactly the right way to retrofit your ac, although a lot of people do so and don't have many problems with them. You're supposed to replace your hoses and o-rings with non-permeable ones since the ones used w/ R-12 are rubber(the oil used in the R-12 fills the pores in the rubber to create a decent seal, the oil used in R-134a will not do the same).  The stock drier or accumulator is supposed to be replaced as well as draining the old mineral oil from the compressor..R-12 uses mineral oil, R-134a used PAG(Poly Alkylene Glycol) synthetic oil, R-134a will not mix with mineral oil. You also instal new high and low side fittings(they're smaller since R-134a molecules are smaller then R-12 molecules). Also, the R-12 needs to be evacuated/vacuumed out of the system before putting the 134a in.

This is the "correct" way to do it, most retrofits aren't done properly though.  For instance, I just put "Freeze 12" in my 93 SE although it's not a drop-in replacement(need to basically do the same things you would when changing to 134a) and I haven't had any problems with it.  :)

[no1kicker]

Ok, thanks for clearing that up.  My AC doesn't work anyways, so I'm torn between fixing it or ripping it all out.  I think if I can't fix it cheap then the 2nd option is what I'll do.

[mfewtrail]

Do you get air from the vents? Is the compressor cutting on at all? If the compressor is cutting on and you're getting warm air out the vents, then you're probably just undercharged.  If the compressor hasn't been cutting on at all, chances are it might burn up if you do recharge the system and get it to cut on(a friends honda did this, but his compressor was out of commission for about two years prior to us recharging his ac system).  If you've got a friend with a manifold gauge set and if you have a can tap, buy a can or two of Freeze 12(bumper to bumper carries it), I believe  the normal going rate is $9/can(12oz cans as far as I can remember)..won't be out of too much money if it doesn't work. You shouldn't have to have any sort of certification to purchase it, but it could vary by state.  Do a search for Freeze 12 on the W-body board, there was a post about it a while back if you're interested in reading more about it/peoples experiences with it(my 93 SE is still blowing cold and working fine after a month or so w/ the freeze 12 mixed with some old R-12 :D ).

[no1kicker]

Hmm, all my car does is blow hot air.  I don't remember hearing the compressor, didn't really listen for it though.  I think pep boys sells freeze 12 and you need a license to get it, or I could be thinking of other stuff.  $9 a can isn't bad.

BTW any idea on how much the entire AC system weighs?  (Always looking for that tenth!)

[mfewtrail]

Stripping the whole system would probably net you 20-30lbs, not really worth it in most cases(the heaviest thing is going to be the compressor, the condenser probably weighs less then a pound by itself), I stripped the ac system out of my other car though.  Took off about 25lbs total from my Volvo. Removing the condenser would probably help with fitting a large FMIC in the future though and could add a bit more flow through the stock intercooler.

[pontiac6ksteawd]

I know this topic hasnt been touched on in MONTHS, however I thougt I would post this.... This is the write up I posted on the w-body board for the TGP...

Ok, most have found out that the TGP low side fill port is located under the turbo. It requires alot of work to charge the system, and do it without burning yourself. Well, I found a better way today...

First off, lets start off with the Drier/accumalator. Its located in front of the turbo, and has fairly easy access. Its aftermarket part number is 33171. This part has no serviceable ports, and usually requires replacement after so much time.

So with that in mind, how about replacing it with one that has a low side service port built in? Thats what I did today. I took out the old drier, part number mentioned above, and replaced it with another drier, aftermarket part number 33206. No modifications are required with this new drier. Just remember to replace your old o-rings with it. Its quite simply plug and go type of thing, put in the new drier, vac the system down, and fill up with R-134a or R-12 (I did R-134A).

There is 1 diference inbetween the 2 tanks, the low side port of course. Other than that, theres nothing else. Althou I have one recomendation, make sure your car is cold and cool befor you start doing this. I didnt, and now am nursing some burns on my fingers.

Old part # = 33171
New part # = 33206
Various O-Rings, which usually come with the new tank.
Autozone does stock it, Advanced does also stock it. They may have to order it thou. Not sure of other part stores.

To the mods: posible to make this into a FAQ or something along those lines for the other users? Thanks..

[Dark Ride]

Thanks for the info, I was planning on replacing the accummulator when i repaired the AC, looks like I'll replace it with that one instead.

Also how do you evac the system, do you need a special machine to do it?  And to charge it after retrofiting it to 134a can you just buy one of those "Check And Charge" kits and hook it up to the low side port?

Thanks,
Mitch

[pontiac6ksteawd]

I had mine professionally vaced down. It cost like 30 bucks at my local instant oil change place.

As far as charging it goes, you buy a retrofit kit from your local parts store. It will contain the ditting adapters to take the nipples from R12 to R134A. It was also contain the oil needed, and the freon to charge the system. The kit costs about 38 bucks.

[Dark Ride]

Cool, Thanks