Ford Muscle Cars Tech Forum banner

1 - 14 of 14 Posts

·
Premium Member
Joined
·
292 Posts
Discussion Starter · #1 · (Edited)
I'm actually a little intmidated here...

OK. So after some craziness in my life I'm about to get back to work on my 7 Litre. One of the few unreplaced items is the factory A/C. I have a brand new replacement compressor, compressor clutch and switch with wire. I have also found a company in Florida that will rebuild my factory hoses and most importantly, in my inheritance of my uncles shop and collection I found a few cases of R12. Now here is the question how hard is it to pull the evaporator? It looks like a pretty large piece of my firewall. I assume the carb and all vac lines will have to come off, but will that do it. is this even possible with the engine in? Should I worry about it, would a simple pressure test suffice? I want this car done right. I used to just cut off those horrible power robbers in the past, but I'm getting older and do live in Texas.
 

·
Registered
Joined
·
1,059 Posts
I wouldn't mess with the evap unless you have a problem. If you do, there is a cover where the hose goes into the AC housing on the firewall. I think once you remove the cover the evap will come out.
 

·
Registered
Joined
·
5,337 Posts
Are you going to do the charging of the system yourself?
 

·
Premium Member
Joined
·
292 Posts
Discussion Starter · #4 ·
Are you going to do the charging of the system yourself?
No, my vac pump died. I want it pressure tested before I waste my precious R12. I've got the gauges and a shop that'll do the test and charge using my refrigerant.
 

·
Registered
Joined
·
5,337 Posts
How long has the evaporator been opened?

You might work a deal with the shop whereas you bring them the car after install, and they will vacuum and fill with R12. If it will not hold, they should be able to tank the R12, allowing you to replace the evaporator and then they will refill it using the saved R12. You just trade them pound for pound with your cans afterwards.

You can also rent a vacuum pump at most tool rental centers.
 

·
Registered
Joined
·
10,327 Posts
If it were me, I'd sell the R-12 to pay for the system, and use a R-420a or R-134a version. I have yet to convert a 12 system to 420 or even 134 that didn't cool great when set up properly. 134 conversions may require a new expansion valve to adjust properly. Most of my stuff was in south Florida with 100°+ and 100% humidity. Horrible summer conditions and a great place to test systems. Ask your AC Tech about options besides R-12. My 2¢.

David
 

·
Premium Member
Joined
·
34,855 Posts
Yep, Kul is right, and when I did AC and took a school for AC, all they did was Apply the vacuum to the system and if it held vacuum for a couple hours, to them it was good to go, and we flushed the system with a nice chemical flush that removes all the crap and old oil to be replaced with new oil and the dichlorodifluoromethane charge.

They also need some Ester Oil lubricant because the PAG oil used with R134a (Tetrafluoroethane) is not compatible with Freon 12.
 

·
Premium Member
Joined
·
34,855 Posts
David, when I was in Nebraska converting 12 to 134, they were crap at cooling at temps over 97*F. Until you were on the road and getting good flow across the system removing the heat it wasn't all that great.

High side Head pressures upwards of 350 PSI were required to get temps in the dash down to the mid 40's. Of course high humidity was the biggest deterrent in the worst cases.
 

·
Premium Member
Joined
·
5,915 Posts
Re: I'm actually a little intmidated here...

Now here is the question how hard is it to pull the evaporator? It looks like a pretty large piece of my firewall.
Better late than never! I agree it is an intimidating looking cover. But according to this, it will come straight off. the screws on the bottom lip are held in by speed nuts.
 

Attachments

·
Registered
Joined
·
1,059 Posts
Removing the fender/inner fender is only an issue with the heater core and heater hoses on cars with AC, not an issue on non-AC cars. The evap is under the cover that Putts posted.
 
1 - 14 of 14 Posts
Top