namvet6869

bought my 81 2 years ago with the ac having a bad evaporator. apparently they was putting freon in it and must have had the pressure wrong since they blew a hole in the bottom of it. anyway , after i bought it i removed the comp. and pluged the lines. thinking about repairing the system this winter. would i be money and headache ahead by just buying a new system from ecklers and replace everything or would it be safe to just replace the evaorator???????? will it come out without tearing the whole dash apart?????? think the book says it will come out from the engine compartment. sure looks tight in there though., namvet

jed992

Just a few months ago I removed mine thru the engine compartment. Wasn't too bad a job. I had removed the accumulator first because I converted to R134A, so that may have given me a little more wiggle room. I believe there was only abou 4 screws holding the evap case together. My evaporator had a small hole in the stem. An AC shop told me to throw it away, but a radiator shop welded it for me for $70. It's held a charge for a couple of months now.

markdtn

I would just replace the evaporator. Not a simple job, but not impossible. Yes, it is done from the engine side. Be sure to clean out your lines and replace the orifice tube and accumulator (filter/dryer) at the same time.

namvet6869

thanks for the replies. believe i can handle the evaporator. what is involved with switching to E134A?????????

namvet6869

sorry for the mistype. R134A

chvet73

I was not able to get my R134 conversion to cool properly until I changed the condensor out to a new crossflow version.
I also changed to a Sanden compressor. And did the C4 fan conversion. It will freeze you out of there now.
If you have a/c experience you can do the conversion.
It will cost more to upgrade to a complete system but be an easier job. If your going to go with a kit, go direct to the suppliers such as Vintage or HotRod air. Ecklers is just reselling one of those anyway.

jed992

There's tons of info on how to do this on the forum. You can get most of the parts from your favorite local auto parts store. Here's the basics:

1) flush out all lines, evaporator, and condensor with cleaner. You'll need 2-3 cans. Then used compressed air to get out any remaining fluid. Don't flush the compressor!
2) remove the compressor and drain the oil. Replace it with Esther oil. It should hold about 8-10oz. Make sure you manually rotate the compressor to get all the oil out.
3) replace the accumulator, or get a rebuild kit from one of the vendors. The rebuild kit is basically just new O rings and new dessicant
4) replace all O rings with new ones rated for R134A.
5) replace the high and low adapter fitting with adapters for R134A. They will simply screw onto the existing ones.
6) evacuate the system with a vacuum pump. I was able to rent one along with gauges from a tool rental place for about $30 for the day.
7) add freon, about 2-3 cans. I'd recommend getting a can with some leak detecting dye in it, along with UV glasses to see if you have any leaks.

If you can't find a vacuum pump to rent, you may want to just take it to an ac shop to have them evacuate and charge the system.

chvet73 may be onto something with replacing the condensor. My ac only gets down to about 50 degrees, which is a lot better than 118 like it used to be when it didn't work.

chvet73

When all was done I can get below 40 degrees. The condensor definetly makes a difference. Anything that will increase air flow thru it will help too. I do have electric fans as well.

08vycpe

Before you spend a lot of time and money on expensive components when you change over to R134a consider one of the new variable orifice tubes in place of the original OEM tube.

The orifice tube is what controls the pressure differential between the high and low side. A modern variable orifice tube will improve the cooling considerably over your almost 30 year old tube. A direct replacement for your old orifice tube is $0.88 to $6.00 depending where you purchase it. A variable orifice tube will be $25.00 to $40.00 depending where you buy it. Be careful when removing the old tube as they are delicate and the plastic is old and brittle and can break easily. If your orifice tube screen is full of gunky the flow will be restricted. If it is full of metal chips it is a sign that your compressor is failing. You can rent an orifice removal/installation tool from Autozone for free.

Also, the old A6 compressors take around 10 oz. of oil but the R4 compressors only need 5.5 oz. Don't overfill with oil or you can ruin the compressor. Use Ester oil as it is compatible with both R12 and R134a in case you leave behind any old R12 oil.

S489

i am wondering why the evaporator must be replaced?
thanks

S489

bump
no takers? i may start new thread to lay out thoughts; was just making sure that the condenser was not being confused with the evaporator, although i can see where the later evaporator does not have the 3rd tube to the VIR.