Thread: Insulating the AC system???

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here in Tx the temps are 100+ during the summer and I was wondering if I could cover , or what to cover with insulation to get the most cooling I can. I have a 84 chevy truck that seems to be losing a lot of the cold air in the system. Any ideas? I have installed a shut off valve in the line that carries hot water to the heater core to keep heat from the coolant from cirlcualting around the AC system. Would it hurt anything if I covered with insulation the plastic housing on the firewall and the canister attached to it ?

I'd have the compressor, dryer and evaporator checked first. If they are in good shape, just have the system re-charged . No amount of insulation is going to help if the systems components are not up to snuff.

My 76 has the same problem.
I have all new compressor,hoses, filter and evaporator.
It feels as though its drawing air from the outside instead of recirculating cabin air.
I can hear the air flow whistling out the window seals when I turn it on.
I have to check all my vacuum actuators.

Edit: I just checked my service manual and this system only recirculates inside air on MAX A/C setting only.
All others call for outside air intake.

I went out and started with the basics.
I took my vacuum pump to the vacuum ball and discovered a nice hole in it from when our refrigeration guy blew up my evaporator.
Vacuum is now good and I got a huge difference in cooling as I'm now recycling cabin air.
I'm glad I read this thread.
It finally got me off my duff to fix the problem.

bigtruckdriver is the compressor kicking in and out a lot if so could be low on freon. being a 84 it would
still be R-12 also unless someone has changed it. tinting the windows would help keep out some heat.

thanks for the tips guys. I have replaced the compressor , evaporator, and the check valve , forgot the name of that part. Got the system flushed out and converted to the r134. I actually done this last summer but had issues about 3 times with leaks and ran out of cash and the temps cooled down so the work was done last year but recently got it charged up again. From what I have read , the biggest problem will be the condensor, It should be upgraded also to a bigger unit for the r134. Also insulating the evaporator will not do any good and may harm the system but I think I will be fine insulating the plastic housing but will have to use some thing that will handle the heat.
I just got the windows tinted , for fathers day, and am going to pull down the headliner to see if there is room to put some type of insulation on top of that. Later today when the sun goes down, 100+ outside right now, I am going to pull the front grill off and clean the condensor and front of the radiator.

then A/C lines going into the evaporator housing did you put the tar like sealer back there. if not your pulling
hot air in from the engine compartment. what I was told on mine was the r-12 condenser was completely
different from r134 and it would build to much head pressure from heating up, but it worked just fine. I had a hose start leaking and replaced everything and went back to r-12. I feel for you cause it's HOT in Georgia too and we need the
A/C got spoiled.

Originally Posted by BigTruckDriver

thanks for the tips guys. I have replaced the compressor , evaporator, and the check valve , forgot the name of that part. Got the system flushed out and converted to the r134. I actually done this last summer but had issues about 3 times with leaks and ran out of cash and the temps cooled down so the work was done last year but recently got it charged up again. From what I have read , the biggest problem will be the condensor, It should be upgraded also to a bigger unit for the r134. Also insulating the evaporator will not do any good and may harm the system but I think I will be fine insulating the plastic housing but will have to use some thing that will handle the heat.
I just got the windows tinted , for fathers day, and am going to pull down the headliner to see if there is room to put some type of insulation on top of that. Later today when the sun goes down, 100+ outside right now, I am going to pull the front grill off and clean the condensor and front of the radiator.

Did you change out your flex hoses when you switched to R134a?? I believe that the material used for R12 is too porous for R134a - the molecules in R134a are smaller, and your charge will slowly leak out if you are running old hoses. You might give someone at Vintage Air a call and be sure I'm right on this before you change any parts, but I think I'm telling you right.

Originally Posted by rspears

Did you change out your flex hoses when you switched to R134a?? I believe that the material used for R12 is too porous for R134a - the molecules in R134a are smaller, and your charge will slowly leak out if you are running old hoses. You might give someone at Vintage Air a call and be sure I'm right on this before you change any parts, but I think I'm telling you right.

I read an interesting nugget on the hoses.
It said that an R-12 hose that's actually had R-12 run thru it previously would be fine.
A brand new R-12 hose that uses R-134a right away will leak.
Of coarse all the o-rings should be the green ones for 134a.