asherwood

Since the engine is out and I do want the air conditioning working again when I'm done, I need to know what should be replaced?

I plan to replace all of the o-ring seals with 134a compatible type, but it has also been recommended that I replace the receiver/dryer with a new unit.

Is this the best route to follow or/and are there other things that I should replace and do?

boosted1205

iTrader: (9)

You need to rememeber that it needs complete flushing of the old system. The receiver and o rings need to be changed. I'm not sure if you have a leak somewhere but if it does have a leak, get that fixed before anything. The molecules on the R134 are much smaller than R12 and it will leak much faster. You also need to follow proper precdures or else the compressor will freeze.

Tripple 7's

All r-12 o-rings are the same as r-134a O-rings

It wouldnt be a bad idea to cange them anyway as they are by now old shrunken D-rings.

And yes it is recomended to change the Accumulator/Drier whenever doing an a/c retrofit.


Also you do not need to flush the system when doing a R-12 to R-134a conversion.

I have done countless retrofits without flushing having no ill effects in performance or system faliures do to not flushing a system.

RoninAutoBoX

There are many BS rumors about what needs to be changed in a conversion, which had many people paying almost and over $1000 for conversions all throughout the 90s, then a shop called Artic Air; founded by one of the founders of ASE itself came up with a $69 conversion. You don't NEED to change a darn thing. The only thing that you have to do is watch how much of the stuff you put in the system. If you don't reduce the amount of fluid in the system, it will overpressurize. That is the only difference.

I would still recommend a replacement of the reciever anyway, as it should be done after a good decade on the road anyhow.

Josepi

Freeze 12 is a drop in replacement for R-12. Costs around 5-6 per can and is said to be more effective than 134a.

Zach McAfee

Now I don't know about that. Are you talking about 15 nanometers vs. 30 nanometers in molecular length? You may be thinking about the difference in oil viscosities and compressor sealing problems, not line sealing problems. This may result in a lower compressor efficiency, depending on the new oil type.

Check this site out and scroll down to the R134a section for more info. http://www.mbendi.co.za/cpieng/lube-r.htm

I recharged my system with R134a and it does just fine. Takes a while to get cool above 90F, but it's so nice having A/C! The $30 'kit' is just three cans, a new fitting, and a hose to go from the can to the low pressure fitting. I should have bought the freeze 12 like Joe said, but it was sorta impulse buying at the AutoZone.

J-Rat

iTrader: (2)

I used this product in my FC with no ill effects. Whereas the R134 conversion caused my coolant hoses to burst.

Jarrett

Zach McAfee

How many cans of 134 did you use? I used two, which is about 85-90% of the R12 OEM capacity.

asherwood

Well, the conscensis seems to be:

1) change the receiver/dryer
2) the o-rings would hurt either

In Canada R12 can't be bought, so 134a it will have to
be. The leak was caused by the cruise control line rubbing on the aluminum crossover tube (near the firewall), wore a hole right through it so this will have to be replaced too.

sound good?

asherwood

quote: I used this product in my FC with no ill effects. Whereas the R134 conversion caused my coolant hoses to burst.

Jarrett

Hey Jarret, do you think that the burst hose was due to 'over filling'?

J-Rat

iTrader: (2)

Well, the running pressures were fine for R134, and its commonly known that R134a runs at a signifigantly higher pressure. So, who knows?

I just use Freeze 12. Same stuff as R12, but legal..

asherwood

hmmmm, I wonder about having my A/C serviced during the next trip south, maybe while at the next SevenStock!

How much to do a pressure test and refill in Cali?

hIGGI

iTrader: (7)

we directly replaced R12 with

R401A

http://rx7cz.net/photos/workshop20/IMG_1359.JPG

no ill effects, cold like ice...
price for complete refill was around $60 with all tests for leakage etc...

Zach McAfee

Different refrigerants operate at different pressures, but the system will only operate at the pressures the compressor and expansion valve produce. That is, of course, if you fill the system with the correct amount of refrigerant.
Your right, R134a does operate at a higher pressure. Thats why my A/C doesn't work well when it's over 90*F outside. It doesn't transfer the heat as well at the non optimal R12 pressures.

nopistons

Where can you get Freeze-12? Do the big chains (Pep Boys, etc) carry it?

J-Rat

iTrader: (2)

Yes they do, but you need a license to get it. The license is easy to get.

Cheers!

freeze 12 is butane or propane based. I thought about it... but the fact that if you get into a car accident, one that is bad enough to have the whole front end smashed, this would mean the possiblilty of the lines and hoses on the AC system damaged.

I for one do not want compressed propane or butane leaking at that point.

But the chances are slim. I just don't like it. SO i stopped considering it.

J-Rat

iTrader: (2)

IS that why it says "non flammable" on the can?

Jarrett

NZConvertible

I got one of the service guys from work to top mine up with R406A, which is a non-CFC replacement for R12.

I'd hate to think of the damage those of you chucking in R134A are doing to the compressor. Mineral oil is not compatible with R134A, and much be replaced with synthetic oil to ensure the oil and refrigerant mix properly and keep the compressor lubricated.

asherwood

So can I ask the A/C shop use R406A for the re-assembled system? Can you even get R406A in Canada?
hIGGI, mentioned 401A

I can't believe how troublsome some of the things on this car can be

And where can I get a set of o-rings?

JPA

What a great topic. I just bought my 88 vert and on the way home the cool (not cold) A/C started blowing hot, having blown a fuse (clock and mirrors were out as well). I stopped off at the dealer, and they said it was supposed to blow the fuse when it is low on freon (not true). They said I needed a conversion and recharge, and I bit. $280 later it was fine (for a week) then the car would not idle, dying at stops. I took it to another dealer, on the way home, and as I pulled in the A/C started blowing hot again, same blown fuse scenario, but all of a sudden idled fine.

These characters said that they repaired a short at the fuse box and set the TPS.

When I picked up the car, it was idling in the service drive, and POW! and WHOOSH! and hot A/C again.

I left it, and they called me the next day and said a hose blew (not true, it was the high pressure plug at the back of the comp) and take it back to the first dealer that did the conversion the week before as it was related.

I did. They said it needed an A/C hose (not true) and that they could not get them, take it away.

I took it to Cartek (Stephan you are great) and low and behold it needed a compressor.

The fuse was blowing because the compressor was locking up or working too hard.

Related to the conversion?

American Express thinks so, and credited me both lousy dealers charges.

now

iTrader: (1)

you are in canada get what you need to fix the leak
change the dryer and get yourself some redtek
or similar you don't even have to evacuate the system
with redtek, I do just to make sure there is no moisture
in the system then charge with this stuff, it works better
than r12 and will not damage the compressor, its
operating pressure is lower and its molecule is
bigger so it will not leak as much. there are other alternatives
out there but be careful as some are blends of all kinds
of stuff, even r22! which is really bad for your auto system.
I have done a couple r12 to r134a conversions
they are a pain to do right and not one person was happy with
the end result.
I use a product called glaciergold(r12a) and have done retro's
from r134a to r12a because lots of the early 134a systems
didn't work well.
the r12a carries either oil well so flushing the system isn't needed
in either 134a or r12 systems.
I am in alberta and would be happy to help ya out

matt

asherwood

This is really cool Matt! I have heard so many horror stories about R134A, I want A/C but not with all of those problems!

I have a receiver/dryer on the way (AC Delco unit), Looking right now for a set of o-rings (any ideas?), the leak was caused by the cruise control cable rubbing a hole through the aluminum crossover tube attached at the firewall (looking for one of those now).

Where in alberta are you?

Al

now

iTrader: (1)

i think you really only have to change the o rings on the
part you have to replace, as for where to get the correct
size o rings,,, i have always gone to the dealer for
them, they are not that much from the dealer.
I am near edmonton alberta..
matt

asherwood

Matt, this "glaciergold(r12a)", is it available in Canada? Do you use that same amount as R12?

AS for the o-rings, I was only going to replace the lines that I needed to open up when removing the engine.