My IROC sat in the garage for 8 years, When it was parked the AC worked fine. I tried charging it with HC12A as reccomended by my garage. They won't work on any 12 systems any more. At first it took coolant then stopped at about 20# on the high? side (black cap) Compressor would not kick on. Mech says cycle the compressor manually with a paper clip, works fine. All coolant leaked out on the lowside due to a loose fitting, Fixed that Now it won,t take any coolant in. Can anyone offer any suggestions?

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BTW HC12A is a safe Enviro freindly coolant that the mech sold me.

 

You should definitely call it refrigerant, not coolant. Coolant goes in the engine, refrigerant in the A/C.

You should never charge an A/C system from the high side, you will hurt yourself that way. An easy way to tell which side your on is to look at the sizes of the lines. High side will be the smaller of the two. If it were my car the next thing I would do is buy some r-12 off of ebay ( I don't trust replacements, but that is just me). When you are ready to charge evacuate the system with a vaccuum pump. I can't remember the amount of vaccuum you need to pull, but pull it down as far as it'll go and then let the pump run an additional 30-60 minutes. Once you do that start the car, turn the a/c on. Start charging (on the low side). The compressor will cycle very quickly at the beginning... this is normal. The cycling will slow down and stop towards the end of the charge. If you do use an r-12 substitute make sure to find out in advance how much you need to put in.

 

Where do you buy a vacuum pump and how do you use one? Thanks
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By the way Atomic, Your car looks excactly like mine!

 

first off i would never buy r12 off ebay. number one the chances of getting what you paid for is slim to none. the other issue is shipping. most carriers would frown on this i would imagine.

harbor freight probably offers a cheapo vac pump that requires an air compressor to operate. it may pull 20-23 lbs. of vac. most shops will pull to 30 lbs. but they will charge an evacuation fee for this. either one will work assuming the system is in working order.

once you pull a vac. for 30-60 minutes let the system sit for 20 minutes or so before charging it to test for leaks. if it holds vac. with no drop than convert to r134a. you can buy a conversion kit from the parts store for usually under 40 dollars. the freon has the new oil in it and works fine in most instances.

there are more opinions about proper retrofits of freon than i care to count however in many cases you can simply change the fittings, evacuate the system, and add your new freon with oil at approx 75% to listed capacity. i know some may balk at this but bottom line it works.

be careful about charging on the high side too. i would not recommend it. your friend may be used to shop equipment that may charge the high side, however most home applications will charge through the low pressure side.

 

Thanks for the info FC06, I'll look in to the vacuum pump. Any idea where I would find capacities listed? What is dangerous about working on the AC system? Wrong pressure will it explode or what? Thanks again.

 

Where should I start? The highest pressures you'll see on an automobile system, or the potential to frostbite your hand off before you could blink. Tapping into the high pressure side while the engine is running is a recipie to lose an arm. You should AT LEAST learn how it works, that way you have a chance.

By the way, just putting R134 into a R12 system is like putting ethanol in your gasoline engine. It won't just "drop in" and work. Search through the cooling board a little and there are several threads that discuss this.

Keep in mind, if you don't know the dangers of AC systems, your bound to find them...the hard way.

 

If you charge through the high side, your refrigerant can will blow up. Say goodbye to your hand.

go here: www.autoacforum.com and educate yourself before you do something you will regret

 

haha this is why i will never try to work on an a/c system ever, just too damn complicated

when we go to take the 85 elky in to have the system filled/converted we are going to leave it all to the shop to take care of

then i need to take my 85 F150 in to have it filled/converted also


theres a small shop that does a/c just a few blocks from here and another one(truck and trailer repair and used car sales place) about 3/4 of a mile away

might even find a donor car for the trans am and put a/c back on it also





good luck

 

I am a refrigeration tech by trade. What Fastcar06 said is correct. That will get you back and going. You may also want to consider draining the compressor and blowing out the lines, condenser, and evaporator to get any trash and oil completly out of it. Now you can add 4ounces new oil to the compressor and the rest of the oil charge (check specs) goes into the NEW accumulator and condenser. Also clean or replace your orfice tube at this time also. Takes a few hours to do this job right in your yard, but you can do it. And I would since you don't know what has been done to it at the shops.
Nothing is going to cool at an idle on 90F+ days like R-12. Period. Anything besides R12 is going to run a higher head pressure and temperature than R12. But, if you weigh in the charge correctly, (usually around 80% R134a of the original R12 spec), and increase the condenser area or install additional electric fan cooling, you can get pretty good performance with R134a or the blends. What is cool about R134a though is you can always go to Wal-Mart or any parts store and get it when you need it. Some of the blends like HotShot R-414b are much better than R-134a, but sometimes the blends can be tricky to dial in correctly. You're dealing with ounces of refrigerant weight here.
Whatever you choose, do it right. You can blow yourself up by charging through the high side port. A good technician does charge the initial charge as a liquid through the high side to prevent liquid slugging of the compressor, but they have equipment that you probably are not going to have. So just charge it in slowly through the low side as a liquid and you will be alright.
Hope this helps and good luck.