muskiemike

Hello Folks,

Have searched this forum and others, and all I read is, it's not fun . . .

I have a "very" small leak in my R12 freon, (1984) AC system - which has been identified from a freon leak detector coming from the AC evaporator.

So, I am looking for some suggestions, instructions or illustrations as to how to replace the 'evaporator'.

The car is stock, with 34K miles.

I am thinking, do I try some kind of freon sealant, or if I replace the 'evaporator', should I stay with R12 or move to R134?

All comments are welcomed . . .

garryowen

doubt you can find r-12 and if you do would be very expensive.

switched mine over to 134a and works fine.

done a lot ac work on trucks, heavy equipment, and tractors. if you have a leak you might as well fix it.

just as well do it right, any thing else will amount to continued charging and wasting
gas. could result in plugging-runing other expensive components of system.

muskiemike

garryowen, - thanks . . .

I've located some R12 'compatible gas' which is MFG & sold in Canada, it's flamable, but apparently it's twice as effeicent as R12 - meaning you only use 1/2 the amount of the gas, and it's 100% compatible with R12.

and it's cheap.

I was thinking, don't replace the evaporator and perhaps I should just add a can of this 100% compatible gas each year . . .

Your thoughts?

garryowen

most likely its a form of 134 which is fine

these have come a long way from the days of ester oil or pag oil that couldn't be mixed.

i wouldn't consider one can a year to bad.

leesvet

Hold on....

your R-12 "comparable" gas is PROPANE or some home brew blend that is EXTREMELY flammable in many cases, therefore illegal in the States due to concerns over fires and car-b-ques and such...otherwise we'd ALL be using it. True, propane does cool better...also burns LOTS better.

R-12 is available and actually not that expensive anymore. It got close to $100 a lb a few yrs ago then it plummeted after everyone did conversions. Now it can be had for $30 a lb and it IS 2 times better than r-134a as far as efficiency.

The evap core? Not fun, but you already know that. Search here and find the thread just a few weeks ago about this. Somebody did it and noted the tips to help. There is some need to remove or loosen certain engine parts, manifolds and other. If you have the FSM set then you can proceed and use the GM book as the guide. That's what its for.
The housing is clam-shell like, so getting things off of it and room to separate are the biggest concerns.
I would avoid the sealers. The system has orifices and screens that won't ever work well again IF they become clogged with some sealant or particles of solid matter. It MAY seal the leak but if it seals the screens and tiny orifices that are designed to regulate high pressure gas..whats the point?

muskiemike

Folks,

Here's the r12 replacement:

http://www.duracool.com/Duracool/refrigerants.html

Hot Rod Roy

If that leak is in the evap. coils, the escaping gas is going into your cockpit, so you're breathing it! I sure wouldn't want to be breathing any propane or freon . . . nasty stuff, for sure! Don't ignore this leak, it's got to be fixed.

R-12 refrigerant is available on eBay.

Hooked on Vettes

That refrigerant is a blend. When it leaks out of the system you no
longer know what percentage of what chemicial is still left
in the system. Topping off is not recommended.

Stated on a web-site that sells refrigerant blends.

Blended refrigerants must only be charged into a system in the liquid state, otherwise partial separation of the blend will occur.

If a significant leak develops in a system containing a refrigerant blend and a noticeable drop in performance is recorded then the system charge will have to be mechanically recovered, the source of the leak identified and repaired and finally the system will then have to be fully recharged with new refrigerant.

In your case you have a known leak. So you probably won't be saving any money if you have to evacuate and recharge every year.

muskiemike

Folks,

In checking Rock Auto, they do not have an 'evaporator' for a 1984, only a evaporator 'repair kit'.

They do have the evaporator for a 1985 - 1989, I called Rock Auto, they were unable to tell me if the evaporator for a 1985 - 1989 would work on my 1984.

So my question is will an evaporator for a 1985 - 1989, work on my 1984?

bookyoh

Two more leak paths from the rear of the compressor besides the manifold sealing washers. The green o ring on the high pressure relief valve. The outer most black o ring on the control valve. The large green o ring is one (Of two) that is used to seal the cylinder to the front and rear heads. A person with the tools to remove the clutch and pulley would be able to replace these o rings. There are 4 bolts that hold the compressor together.

GregMartin

Maybe check Ecklers and is if the part is the same for 84 and 85 Vette. There is a pretty good chance they would be the same.
The replacement gas you are referring to is a blend or propane and Butane and I believe some vehicle manufacturers are using it in some markets. As a refrigerant it’s excellent but it is BBQ gas. I’ve used it to regas cars before and it works well. In your case I wouldn’t use it because you have an identified leak. The only thing to do is fix the leak then it’s kind of irrelevant which refrigerant you use.