AC Problems

Kinja'd!!! "C62030" (c62030)
06/06/2016 at 19:58 • Filed to: None

Kinja'd!!!0 Kinja'd!!! 10

The AC in the Grand Prix (‘91) has been blowing warm since I got it, and I’m pretty sure it just needs a recharge as the fans and heater all work great. Problem is, I’m pretty sure it needs R12 Freon, which is now apparently hard and expensive to buy, and putting R134 in it will eventually eat the system from the inside out.

I know you can convert from R12 to R134, but it’s reportedly very expensive and some shops won’t even do it. Are there any alternatives for R12 I could use, or am I just gonna be hot this summer?

Thanks, Oppo.


DISCUSSION (10)


Kinja'd!!! Demon-Xanth knows how to operate a street. > C62030
06/06/2016 at 20:02

Kinja'd!!!0

The conversation kits are cheap. Just have a shop do that. Is it bad that I miss my ‘91 LE way more than my ‘04 GTP?


Kinja'd!!! Birddog > C62030
06/06/2016 at 20:11

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There’s always Propane. But it’s kinda sorta illegal to do.

I’ve done the 134 conversions and never had a self destruct situation. You can rent the vacuum pump to make sure there’s no air in the system before recharging. Air/Moisture in the system is what kills them.


Kinja'd!!! Steve in Manhattan > C62030
06/06/2016 at 20:14

Kinja'd!!!0

Is it still legal to put R12 in an old car? I am so far removed from these issues now ....


Kinja'd!!! C62030 > Demon-Xanth knows how to operate a street.
06/06/2016 at 20:23

Kinja'd!!!1

Every Pontiac interior after this generation just became a hateful clusterfunk of pods and nodules and podules that look like they were designed by the Flood from Halo.


Kinja'd!!! C62030 > Steve in Manhattan
06/06/2016 at 20:25

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According to AutoZone, it’s legal for the shop to fill it up with R12, just not legal for you to buy it or do it yourself, as far as I know. So I’ll probably do that as it’ll be much quicker than retrofitting, and R12 is miles colder in an original R12 car.


Kinja'd!!! Demon-Xanth knows how to operate a street. > C62030
06/06/2016 at 20:26

Kinja'd!!!1

My ‘91 felt more balanced, the ‘04 seemed like the interior was done by 5 different people who never met each other once. The ‘91 was by far the most comfortable long distance car I’ve ever driven. Six hours straight and zero fatigue. Sat six with the benches.


Kinja'd!!! C62030 > Demon-Xanth knows how to operate a street.
06/06/2016 at 20:30

Kinja'd!!!1

Normally I would love a cushy bench, but the buckets in this are just so nice. They do not encourage good posture, as there’s zilch lumbar support when you sit up straight, but if you slump a little it’s just lovely. And of course, it’s still ‘90s GM, so none of the panels fit right and everything sags and the plastic on the B-pillars is warped a little but there are so many buttons, you can’t not like it.


Kinja'd!!! Urambo Tauro > C62030
06/06/2016 at 20:31

Kinja'd!!!2

Converting to r134a by changing the fittings really isn’t good enough, because r134a is a compound composed of smaller molecules than r12 that r12-rated hoses (especially 25-year-old ones) cannot hold. A proper retrofit needs hoses and O-rings that are rated to handle r134a.

And the system needs to stay sealed. You can’t simply top it off every year, because when r134a starts to leak, it releases its smaller molecules first. So any remaining compound in the system is no longer r134a refrigerant. Topping it off does not restore the mix to its proper balance; it just makes heavily diluted refrigerant, and AC performance suffers.

The most cost-effective way to get the AC system working properly again is to do the wrenching part yourself, replacing the accumulator/drier, orifice, hoses, O-rings, and anything else that needs replacing (coils if leaking, compressor if faulty, etc.), then having a shop evacuate and recharge the system. It’s still gonna be a bit expensive, but you’re gonna save a LOT of money versus have a shop do it all.


Kinja'd!!! BloodlessWeevil > Urambo Tauro
06/06/2016 at 21:53

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Thank’s for the technical explaination. We need more engineers around here (...and everywhere else, for that matter.)


Kinja'd!!! Urambo Tauro > BloodlessWeevil
06/06/2016 at 22:25

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Not an engineer, but I’ll take the compliment! The thing that helps me to understand the molecule leakage problem is to think of it like coolant:

Say you’ve got the standard 50/50 glycol/water mix in your cooling system. If there was a way for all of the water to leak out, but leaving all the glycol in the system (silly, I know; stay with me here), then topping it off with pre-mixed coolant would result in the wrong mixture. You’d now have 75% glycol and 25% water.

If it kept leaking water only, another top-off would result in even less water in the system. Without water, the liquid’s ability to absorb heat from the engine and release it through the radiator is diminished, and the car can’t cool as well.

The problem is that with refrigerant, you can’t really analyze the compound and add just the missing molecules (like you could add water to straight coolant). No, it’s gotta be fully drained and filled back up with the right mixture.