AC outlet temp

[William F.]

Re: AC outlet temp

Ken,
Does the entire cold pipe need to be wrapped or just where the expansion valve bulb comes in contact with this pipe? Also, where is the rubber drain on the box-assume you mean box that contains evaporator
Thanks in advance.
Bill Ford

[Ronald L.]

Re: AC outlet temp

The climate engineering experts will tell you that studies show humans cannot detect the difference in 2 degrees. So if you want an original car (which from the comments it may be that is not the objective), follow William's advice above and leave it alone.

If however, you want to maximize frigidity, then you need to change all your components to new stuff, modern made condensor, compressor lines and evap core. Make sure you have the special new charge that you can look for parts per billion leak, with a black light, then re-engineer your compressor side of the system.

That means, from the outlet on the compressor up to the heat exchanger in the dash, wrap it all with foam insulation, metal to reflect heat away in the engine compartment. Do the same thing to the heater/AC box and all your ducts.

Now you did not tell us where you live and why it is such a problem to get 2 more degrees, but one of the earlier posts was dead on that you are not going to get more that about 25-30 over ambient.

All this is altitude humidity and temperature dependent.

After all this if you are not satisfied, then you have the fun part to deal with - the body.

You are going to have to seal up that leaky beast. All your cold air is leaking out, dash, doors and rear body. You can get spray chalk, you'll need to chalk test all your body seals to be sure there are no thin spots that allow air to leak out. New water shields to the new technology that provide sealing around all your screws, lots of dum dum, etc. The reality is you need some leakage but these C2 cars were so leaky that you need to seal it up as good as you can.

[Jack H.]

Re: AC outlet temp

"Also, where is the rubber drain on the box-assume you mean box that contains evaporator"

With car on lift, look at the bottom center of the Harrison air box that bolts to the firewall in the engine compartment. You should find a circular 'nipple' with a rubber 'bladder' attached that's held in place with a ring clip.

The bladder is what allows condensate moisture to run out onto the ground from frost that forms on the evaporator. MANY aged original cars are missing this rubber piece...

Also, effective cooling can be lost due to air-borne crud (especially dried leaves) that get into the air box by way of the exterior cowl. Running the blower fan can FORCE them into the evaporator's cooling fins and effectively 'plug' air flow through the condensor.

Before launching on wholesale refrigeration part replacement campaign, make sure your 'plumbing' is clean/clear. It's NOT uncommon for older cars that have been driven to have the air box (both evap fins and 'weep' valve bladder) clogged with debris...

[Ken A.]

Re: AC outlet temp

Ken,
Does the entire cold pipe need to be wrapped or just where the expansion valve bulb comes in contact with this pipe? Also, where is the rubber drain on the box-assume you mean box that contains evaporator
Thanks in advance.
Bill Ford

Wrap as much as you can, also at full operation(see above) make sure you have freon hooked up and ready to add if sight glass has bubbles, BUT do not exceed max head pressue. Jack is correct re: trash but wrong about frost. If the evaporator freezes up, then you're low on freon. Working correctly the system dries the incoming air and the water goes out the drain tube. Also, BEFORE you added freon, you should have maintained 30 inches of vacuum for at least an hour to make sure there were no leaks(with the pump off). It was my experience that P/U trucks and Corvettes worked the best at cruise(better than a pass car) because of the smaller cabin volume. R-12 cools much better than R-134. Remember to read the owner's manual & operate the system at least 1X/month to preserve the compressor seal.