Hey guys, I have a quick question. The red car was converted to the 134a refrigerant. Last year is worked fine. I'm assuming that through the winter I lost most of the refrigerant out of it. I have a recharge kit. My question is this: I put the guage on the low side and started the car, turn the a/c to max and the compressor never turns on. My gauge reads 35psi. According to the directions it tells me that if my compressor doesn't turn on go ahead and add one can. Now since my gauge already reads 35psi is it safe to go ahead and add one can?
No where's in any of the directions does it say anything about this. I would just rather be safe than accidently overfill something.
TIA

 

You won't overfill it if you are talking about one of those small cans of refrigerant about the size of a can of spray paint. If you have only 35 psi, it would be a better idea to start from scratch and relieve the pressure and pull a vacuum , THEN fill your a/c.

 

thanks, can I just relieve the pressure by connecting the coupler to a hose and let it relieve to air?

 

NO youre supposed to reclaim r134a refrigerant- you may not vent it to the atomsphere

 

Venting is a NoNo. Al Gore says so. Also,if you vent you will need a vacuum pump to evacuate the system before you can refill.

 

Well I got a bit lucky. I went ahead and hooked up a can of 134a and as soon as I opened it the compressor kicked in and filled the system back up. Nice and cold again. And of course I had my vacuum pump next to me just incase I had to evacuate what was in there

 

how cold is COLD...a little jelious here, mines cold but not sure its cold enough...i charged mine too and the guage says " FULL" is it reeallly cold?? lol

 

I'm kind-of supprised no one has said this yet, but when you install freon into your car you must have the compressor turning. It cannot suck in freon without the compressor turning.

To force your compressor to engage you need to short the wires on the low pressure side switch. Remove the connector, using a paper clip and put it into the connector holes. You normally don't want to do this because exactly as it says "It a low pressure switch". If you have low pressure it will shut off the compressor so you don't burn it up. So, you jump it only when loading freon into your car. When shorted your guage will show the correct reading. If the compressor isn't turning whatever the guage says doesn't mean $hit.

Lastly for some reason when most people retro there R12 to R134 they fail to use a retro low pressure switch. Yes, the pressures are different from R12 and R134. Here is a link and a pic of the retro switch... http://www.fjcinc.com/pdf/2007catalog.pdf (page 61)

 

ok so i hook up the guage with the car on...AC on too. then leave the turn dial on the guage shut all the way tight to the right..then go and trip my low pressure guage? and it will give the the reallll reading? seems risky

 

I'm not saying to leave it on for 2 days... You hook up your guage, you start your car, your set the the rpm's to 2000, you short the connector, you take the measurement.... About 1 minute. If low, you add the freon while the compressor is running.

Seems Risky? yea, but that's the way every AC guy does it... Just trying to help you.... Go ahead and continue your way if you want.... Miracles do happen sometimes...

 

I got so cold tonight that I had to turn the heater on. I wish it would get that cold in the daytime when the sun's beaming down inside the acrylic top. No complaints though after going two year's without a/c and heat it's all good.

 

I agree with 93 corvette. If you turn on your A/C and the compressor isn't running, you disconnect the low pressure switch and momentarily jumper the connector. If the compresor kicks in, you have no freon. Hook up the can, right side up and start the engine, turn on the A/C, and jumper the switch. let it run like that till you count to 15, then put the connector back on the low switch, and it should kick back on, and keep running. The most common problem is the compressor seals. If the thing sits all winter, the reduced temps may cause the compressor to leak. Refilling it will only get you through another summer. Most places that repair compressors will charge you about $60 to reseal a good compressor. If the compressor is junk, some shady dealers will go ahead and replace the seals, and tell you the compressor is "weak".
Weak to me means shot. If your compressor comes apart while it's running, you will never have trouble free air conditioning again as long as that car is in existence. The compressor will fill your system with metal particles, and trash. That trash will shortly wipe out another compressor, clog your expansion orifice, plug up your evaporator and condensor, and render the system inefficient.

 

wow thanks guys...really good info..

 

This is good information. Thanks!

 

Im still rinning R12 in my 88 and I really have to say it runs VERY cold. What is the cost to change over to R134 when it needs to ??

 

The conversion isn't all that expensive. What is expensive is evacuating the R12. Not many people will touch it, at least in my area. The retrofit kit itself is basiclly the fittings on the hi / lo lines, and the replacement low pressure switch.
R12 does run colder than the R134a

 

Do not change over to R134 unless you have to break open the system (ie replace a compressor, repair a broken line...etc..)
R12 is the best! There is nothing better!

If you need more R12, then goto www.epatest.com and pay your $25 and get your license. Then goto Ebay and buy as much R12 as you need.

If you must change to R134, then you need to flush the system, replace the accumulator, replace the orfice tube, replace all the rubber "O" rings, pull a vacuum, replace the low pressure switch, and load the freon. The 1st time you do it... it's hard, the second time is extremely quick.

Remember, if for some reason you get a wild hair up your a$$ and want to convert to R134 because you don't want to buy the license for R12, then most car repair places will usually suck it out for free. They sell the R12 to reclaimer, who will reprocess it again and sell it. They make alot of money by just connecting hoses to your car. That's why they usually do it for free.