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'85 Factory AC System -- How to Repair


ford4wd08

Well-Known Member
Joined
Nov 12, 2018
Messages
1,259
City
Alcoa, TN
Engine
2.8 V6
Transmission
Automatic
My '85 BII has the factory AC system on it. I don't recall it ever working and I was born in 1990 ha

Anyhow, what would be the first steps to trouble shoot it and see what I need to do to repair it?

I doubt the compressor is good and I would assume it be would best to convert to R134A from R12?

Can I reuse the condensor and evap coil if I flush it and it doesn't leak?

Any tips on where to start?
 
Convert to R134a? Yes

Replace the compressor? Yes

Reuse evporator and condenser? Yes... flush and blow them out with CO2

Replace all O-rings... expansion valve/orfice tube and accumulator/receiver dryer.

Tighten it all up and pull a vacuum to remove air/moisture. Repair any leaks. Vacuum again... fill the system.

This is of course assumes all the electrical controls/wiring and switches are functioning properly.

I'm not sure of the price on the vintage air systems... but I would take a look at those.
 
Convert to R134a? Yes

Replace the compressor? Yes

Reuse evporator and condenser? Yes... flush and blow them out with CO2

Replace all O-rings... expansion valve/orfice tube and accumulator/receiver dryer.

Tighten it all up and pull a vacuum to remove air/moisture. Repair any leaks. Vacuum again... fill the system.

This is of course assumes all the electrical controls/wiring and switches are functioning properly.

I'm not sure of the price on the vintage air systems... but I would take a look at those.

Rock Auto has a compressor kit for $217 that specs for R134A.

https://www.rockauto.com/en/moreinfo.php?pk=5242068&cc=1106143&jsn=2849

I didn't think that was too bad. I believe all the electrical will be ok, at most it would might need a switch.

How difficult it is to flush evap and condensor, can you do it with them install on the vehicle? Or is that something I might want a shop to do?
 
Before deciding on trying to fix it I'd separate the lines and look to see if there's corrosion. If the freon leaked out years ago the system likely got moisture in it. The receiver/drier should be replaced, most everything else can be flushed except the compressor- assuming no corrosion is found. Be meticulous when inspecting it, you can spend a bunch of money and then have it fail.
My truck came with no heater box so I installed a Vintage air system, it was about $1100 plus the compressor because I wanted to use a Fox Mustang compressor. I wish it had an outside air intake but it heats and cools great. If your evaporator core doesn't leak and your evap case and ducts are OK you could buy just the components you need to fix your system a lot cheaper. A compressor is likely available and you could use Vintage Air's universal condenser,hoses and drier. That would retain the outside air feature and factory ducting and controls. I spent a lot of time fabricating ducts.
 
Before deciding on trying to fix it I'd separate the lines and look to see if there's corrosion. If the freon leaked out years ago the system likely got moisture in it. The receiver/drier should be replaced, most everything else can be flushed except the compressor- assuming no corrosion is found. Be meticulous when inspecting it, you can spend a bunch of money and then have it fail.
My truck came with no heater box so I installed a Vintage air system, it was about $1100 plus the compressor because I wanted to use a Fox Mustang compressor. I wish it had an outside air intake but it heats and cools great. If your evaporator core doesn't leak and your evap case and ducts are OK you could buy just the components you need to fix your system a lot cheaper. A compressor is likely available and you could use Vintage Air's universal condenser,hoses and drier. That would retain the outside air feature and factory ducting and controls. I spent a lot of time fabricating ducts.

What does corrosion look like in an AC system, is it rust, or black corrosion?

I had one hose off at one point to work on something and obviously the system didn't have any pressure, but I didn't notice any corrosion.

I think this one can be repaired, hopefully for not too much money....

Just need to look into flushing components and how to do it.
 
^^^ Good advice, and a good hit on the compressor kit; you definitely want to change the receiver/drier and orifice tube. Also consider flushing and reusing the evaporator (can be flushed in place; a flush gun works great), and price and consider getting new hoses (3 needed) and the condenser. Look for a condenser designed for R134A, and the needed green O-rings should be included with the new parts.

That's the route I took on rebuilding my '94 Explorer AC system. That would basically get you an all new core AC system, excepting the evaporator. You retain the original controls, air ducting and blower (nice and OEM). All my parts came from RockAuto, and I'll see if I have the receipt to give you an idea of the cost in 2016.
 
What does corrosion look like in an AC system, is it rust, or black corrosion?

I had one hose off at one point to work on something and obviously the system didn't have any pressure, but I didn't notice any corrosion.

I think this one can be repaired, hopefully for not too much money....

Just need to look into flushing components and how to do it.
You're looking for white corrosion but any color is bad.
A/c flush solvent and a container pressurized with shop air is what we used. If everything looks clean and flushable you could just replace the compressor and drier. You may have to make or modify the hoses where they attach to the drier-unless you luck into an stock replacement drier. When R-134A was released we were given a long list of components to replace when switching from R12, mostly you need to get the oil out of the system and change the charge fittings. Flushing the lines, evap, and condenser, and replacing the compressor and drier should do it.
 
I'll look into this when I get the B2 back this week... I'll post some pics up on here.

My HVAC for the house is a pretty decent guy, I think he would loan me his vacuum pump and maybe even help me charge it for little if any money.
 
I don't think house units use R134a.
 
I don't think house units use R134a.

If that guy has the adapters to hook his gauges to the r134a automotive fittings, he can use his gauges and vacuum pump on the underhood system. I do it all the time. The adapters you can buy, or that come on the Harbor freight guage sets, will screw right onto standard HVAC hoses.
 
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I don't think house units use R134a.

You're right, house system and my 2018 HVAC units use R410.

But I know he has helped a few folks charge cars. The vaccum pump alone would be worth asking.
 
Years ago we bought a freon analyzer for the dealership because some people were mixing refrigerants and we didn't want to contaminate our charging station. I never saw one but apparently some places in the South were charging a/c systems with propane because it was cheaper. It's better to use the right stuff. I have a freon license and wouldn't be allowed to charge a leaking system but Autozone and Walmart sell do it yourself charging kits. I guess they just blow freon into the system and don't worry about evacuating the air and moisture first- or adding oil.
 
Years ago we bought a freon analyzer for the dealership because some people were mixing refrigerants and we didn't want to contaminate our charging station. I never saw one but apparently some places in the South were charging a/c systems with propane because it was cheaper. It's better to use the right stuff. I have a freon license and wouldn't be allowed to charge a leaking system but Autozone and Walmart sell do it yourself charging kits. I guess they just blow freon into the system and don't worry about evacuating the air and moisture first- or adding oil.

Only trouble is that propane goes BOOM to easily....
 
Propane can burn or explode but if you're lucky and it doesn't blow up, your charging station is contaminated junk. If you don't realize it's contaminated you spread it to other customers' cars.
 

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