I can access R12 or FREEZE12 locally.. which would be best to use? My plan is to go and buy a gauge, turn the a/c on, make someone hold the engine at 1500, measure it and then slop some R12 into there. Is that the correct way to do this?

The system has not been converted, as far as I can tell, since it still has tire valve stem like fittings.

I've read that FREEZE12 says you have to evac the system before adding it. Some sites say that is just for legal reasons. Anyone know, for sure? Anyone know if it's actual R12?

As I also understand it, I can just add R12 and not worry about adding any oils or whatever else, right??? So I just need one of those charging trigger things and any necessary adapters??

I'm not sure of what the best ambient temp outside would be, if anyone has a chart that tells you how much to charge according to the ambient temp - that'd be great!!

I want whatever I put in to actually be R12 and NOT have leak sealers in it. The system needs to be charged every 2-3 years so I'd like to not disturb anything and just add some.

Do I have my head up my *** or am I thinking right?

Thanks

 

I think I found the answer to my question about freeze12 (finally)
Freeze 12 FAQ's

Why should I retrofit an R-12 system with Freeze 12 instead of R-134a?
1. Freeze 12 will cool better than R- 13 4a in most retrofit applications.
2. Freeze has a pressure curve which is close to R-12 while R-134a operates at significantly higher pressures than R- 12.
3. Freeze 12 works with the existing mineral oil and does not require lubricant replacement as R-134a does.

#2 implies that it is something else. Who knows. I think I will just go with R12

 

Freeze-12 is NOT R-12. It's a mixture of R-134a and R-142.

 

I see! That makes the decision a lot simpler

 

System has leaked to lose most/all of R12 (not cooling presumably). You should perform a pressure leak test (AC shop) to identify system leaks. These should be repaired before adding any new refrigerant.

R12 is supposed to be recovered for disposal. An Ac shop should recover R12 unless system is empty already.

Retrofit to R134a may be a better long term solution if you plan to keep the car. If you decide to retrofit, you should replace all system orings, receiver/drier, remove evaporator and clean/replace orings. Some replace expansion valve to get one calibrated for R134a.

good luck

 

No no it cools fairly well- it just isn't working 100%
I don't want to stray from good old R12

I want to know for sure what to do to be SURE I put the R12 in correctly

 

Check some simple things first.

Start the car and turn on the a/c. Do both fans on the radiator turn on? Look at the clutch on the compressor. Is is spinning with the a/c pulley?\

You may want to lightly spray down the a/c condenser with water to clean any debris built up on there.

Check that your valve that diverts coolant to the heater core is completely shut off. That is in the engine bay near the firewall on the passenger side. Just follow the two large hoses that go inside the car and you will see it.

Unless you are absolutely sure that you have a low charge, I would not add anything to the system.

 

Both fans = on
Compressor clutch = Engaging/Cycling
Heater valve = Only works manually, but all the way off

Probably will try to clean some things up today under there, definitely want to check the pressure before adding any, but I'm not sure of how to do that.. I know adding too much is a horrible idea, so do I buy a gauge somewhere?

As far as I understand it I need to put the gauge on, blast the a/c, make someone hold the engine at 1500 and check it while the compressor is engaged... right? But what is the right pressure for this car, and does that change with the ambient temperature outside?


Thanks!

 

The proper way to check the a/c is to use a manifold that measures the high and low pressure sides on the a/c.

The outside temp and humidity will change the normal range for both the high and low pressure readings. You need a chart for R12 to figure out if you are within the normal range.