1973 SB Evaporator Replacement

[Pat Bush #35083]

Hi all ---

I am preparing to remove the evaporator from my 73 and was wondering if anyone has any words of wisdom on the removal and reinstallation process. Additionally, can anyone point me to a vendor who would sell the liquid line (condensor outlet to VIR Assy) hose? I have had the hose at a AC shop and they keep telling me they cannot get the connectors to make another hose. I am good to go on the manifold assy.

I have a new Delco evaporator and was considering replacing because the system has been broken/leaking/open for so many years -- compressor burned up, condensor had a leak, and all the hoses were bad. The thought of having to do this job when the car is all put back together seems REALLY challenging. Hoping this approach will be less effort.

Right now there is essentially nothing in the engine compartment except the block (heads are off). The VIR is out as are all the hoses. I figured if one were to clean the case out and replace seals, hoses, and gaskets on the evaporator, now would be the appropriate time to do this. I am pretty much replacing everything else - new compressor, condensor, hoses, and VIR. I just do not want to take a chance at contaminating any of the new components with God knows what!

Any help would be greatly appreciated. Thanks as always -

Pat

[Thad L.]

Re: 1973 SB Evaporator Replacement

Pat

I agree, this is the time to fix that old A/C system, living in South Louisiana, one really needs the A/C to work, because when the temp is above 98 and the humidity is high you can't enjoy yourself when you are baking. Now I really can't help with the VIR system because my vette has a POA system, I can tell you the your system is the coldest system that the general ever put out, that's if it working OK. Try finding a big parts house of industrial hose company, they should be able to help wth the hoses. Now here is my advice on the type of refrigerant to use. Use R-12, but not at first. When your system is ready to go, charge it with Freeze 12. This stuff is a few bucks a can and if you find a leak, you can dump it and not have a heart attack. After a couple of weeks with good cooling, dump it and recharge with R-12. I have found that Freeze 12 and R-134a cool about the same. 51 to 55 degrees duct temp is all I can get down here, R-12 will get 39 degrees on the hottest day if the recirculate doors are working properly. Now some of my norther friends say 134 and freeze 12 work great for them, but here in the swamps we need all the cooling power we can get. I have a supply of R-12 that I purchased for $22 a can! Don't know what it costs in your area? Hope this helps! Thad LeJeune 32187

[Pat Bush #35083]

Freeze 12???

Thad -

Thanks. I've been hearing about this Freeze12 stuff from a bunch of local mechanics around here. Most swear by it and say it performs almost as good as R12 with less head pressure than 134a and less grief converting over (doesn't need ester oil either). It's priced 2X as much as 134a but about 10X less than R12 (and I don't need a license to charge with it). What is this stuff made out of. Quite frankly, it sounds too good to be true.

I wonder if anybody else out here is using the stuff and can report on how it performs......

I too have a very limited supply of R12 left and I have been looking for more.... Care to part with any? :-)

Thanks for the advice.... the quest for the hose continues.

PS - I got the evaporator out with only a modicum of annoyance - what a mess in the case. Never ceases to amaze me how a mouse can get anywhere in a Vette. They were having a party in there. All cleaned and disinfected now. Couple of new seals and gaskets and I should be good to go in there :-)

Pat

[Thad L.]

Re: Freeze 12???

Pat
I realy don't know what Freeze 12 is? Maybe a blend of some kind? You are rite about the head pressure being lower than 134, in fact it is almost exactly like R-12. It just dosen't have that COLD punch like R-12! Now I gunna sound like Joe Lucia "sorry I don't sell my stuff" HA HA. Just kidding Joe! It's getting harder to get down here and when I get another project, I will probably do some A/C work on it so! This reminds me of alot of {for sale} adds that read A/C need recharging, I told one guy "so it's broken? No,it just needs recharging. Then it has a leak rite? He thought a second and said, I guess your rite, It's broken." take care. Thad

[Craig S.]

Re: Freeze 12???

Thad- does the freeze 12 use R-12 charging connections or 134a? My cars still all have R-12 (I have two new 30lb tanks of the stuff....and, like Joe, no it's not for sale) but like the idea of using freeze 12 for "testing purposes" before I dump the R-12 in. By the way, in Tucson in August at 117 degrees, the AC feels nice too!....Craig

[Tom Freeman]

Freeze 12 is a Blend

Freeze 12 is a blend of 80% HFC-134a and 20% HCFC-142b. It is made by Technical Chemical 800-527-0885. EPA approved under the SNAP program for use in auto a/c. Since it is mostly 134a I would think that all the restrictions that apply to 134a would go for Freeze 12, such as new seals and different oil.

tom...




The '73 Spot

[Clem Z.]

Re: Freeze 12 is a Blend

it is R-414B,a drop in replacement for R-12,R-134A and R502. it is more efficent because you use less,90% of capacity in a R-12 system,80% in a R-134A system. there is no oil or "O" ring change needed.

[Thad L.]

Re: Freeze 12 is a Blend

Craig
Yes, you can use your same R-12 fittings! No need to change anything. For all of you guys that are trying to get that A/C system up and running, MAKE SURE that the upper plynum [spelling] door in the upper part of the passenger fender is closing when the knob, lever,wheel is put in the max-recirculate mode, and that the lower door in the foot area of the pass side is opening! If it isin't working correctly you may be trying to cool outside air instead of recirculating the cool air in the cockpit! Thad

[Tom Freeman]

Re: Freeze 12 is a Blend

A lot of people use the term drop-in but all do not mean the same thing. Some think drop-in is one that you can add to your system without doing anything. Per the EPA site it is illegal to add different refregrent to an a/c system without first removing the previous refregrent, no mixing allowed.

I found R-414b on the EPA site and its brand name is Hot Shot and Kar Kool. It is not Freeze 12. Per the EPA site, Hot Shot/Kar Kool, is a blend of 50% HCFC-22, 39% HCFC-124, 9.5% HCFC-142b, and 1.5% butaine. By the way, the HCFC-22 is the one that requires barrier hoses.

The EPA sites for this info is:

http://www.epa.gov/spdpublc/title6/snap/macssubs.html

and

http://www.epa.gov/spdpublc/title6/snap/lists/mvacs.html

tom...


The '73 Spot

[Clem Z.]

freon heavier than air

how does freon 12 get up into the atmosphire if it is heavier than air??

[John Wire]

Re: freon heavier than air

The EPA says so! Just like they say a water saving toilet works as well as the old kind; therefore, you don't have to flush it three times.

My conspiracy theory leads down the patent path for new refrigerants.

[Clem Z.]

(Message Deleted by Poster)

Message Deleted by Poster

[Clem Z.]

patents

i had heard that duponts patents were about to run out on R-12