Did some searching and did not see that data point. On a completely stock A/C system, what is the R12 capacity? Good news is that the condensor fan works, as does the compressor clutch!!!
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From this website it looks like from 2 to 2.65lbs. A/C
Good luck.
Good luck.
quote:From this website it looks like from 2 to 2.65lbs. A/C
From that website: "2 pounds of R12 Freon will fully charge an empty Pantera AC system."
I put just under 2 pounds in mine, and it is coooold.
John
Actually, the specs are confusing. Here is a copy/paste--
The AC system holds 1.2 kg (2.65 lbs) of R134A.[1]
A crankshaft speed of 5,000 RPM is the max that the AC compressor should be active.
Rotary AC compressor produces 37 Deg F at vents with 3.1 lbs of R12.
2 pounds of R12 Freon will fully charge an empty Pantera AC system.
The 2.65 amount is for R134, which should/must be LESS than the R12 capacity. Then is says the rotary compressor takes 3.1 pounds of R12 to fill an empty system followed by the 2 pound spec.
I guess I can look for a sight glass and fill the system THAT way while monitoring pressures - the old school method. Otherwise ...... pull it down and start at 2 pounds to see how it does.
The AC system holds 1.2 kg (2.65 lbs) of R134A.[1]
A crankshaft speed of 5,000 RPM is the max that the AC compressor should be active.
Rotary AC compressor produces 37 Deg F at vents with 3.1 lbs of R12.
2 pounds of R12 Freon will fully charge an empty Pantera AC system.
The 2.65 amount is for R134, which should/must be LESS than the R12 capacity. Then is says the rotary compressor takes 3.1 pounds of R12 to fill an empty system followed by the 2 pound spec.
I guess I can look for a sight glass and fill the system THAT way while monitoring pressures - the old school method. Otherwise ...... pull it down and start at 2 pounds to see how it does.
Yes there are some discrepancies in that link.
I presume you are using the original compressor pump. It would be best to empty out any oil you have in it and replace with new oil. Hopefully you replaced the filter dryer and put in a high / low pressure switch. It is also recommended to replace the expansion valve.
The best way is to vac the system for ~30 mins. Switch off vac pump and check after a while you are not loosing any vacuum.
If you have access to nitrogen you could pressurize the system with that to check if you have leaks. It is cheaper and not as nasty it does leak.
Just dont run the compressor with the nitrogen.
Not sure how much oil you need to add for the original compressor, but if the dryer is replaced and the compressor is emptied you can treat as a new fill with oil, otherwise you might under or overfill with oil.
You can start with 1.5lbs of R12 + oil with the engine off and go from there. Then start the car. You really need to use gauges and temp gauge /gauges to put the correct amount of gas in. Here is a link to general guide on charging your system. A/C guide
I just charged mine over the weekend. R134A, all new hoses-dryer-expansion valve-Sanden rotary pump-trinary switch with front condenser, original evaporator etc. Used most likely less than 2 lbs in the end and got 32 degrees F at the vent with ambient at ~90 degrees F. Very pleased.
Good luck.
I presume you are using the original compressor pump. It would be best to empty out any oil you have in it and replace with new oil. Hopefully you replaced the filter dryer and put in a high / low pressure switch. It is also recommended to replace the expansion valve.
The best way is to vac the system for ~30 mins. Switch off vac pump and check after a while you are not loosing any vacuum.
If you have access to nitrogen you could pressurize the system with that to check if you have leaks. It is cheaper and not as nasty it does leak.
Just dont run the compressor with the nitrogen.
Not sure how much oil you need to add for the original compressor, but if the dryer is replaced and the compressor is emptied you can treat as a new fill with oil, otherwise you might under or overfill with oil.
You can start with 1.5lbs of R12 + oil with the engine off and go from there. Then start the car. You really need to use gauges and temp gauge /gauges to put the correct amount of gas in. Here is a link to general guide on charging your system. A/C guide
I just charged mine over the weekend. R134A, all new hoses-dryer-expansion valve-Sanden rotary pump-trinary switch with front condenser, original evaporator etc. Used most likely less than 2 lbs in the end and got 32 degrees F at the vent with ambient at ~90 degrees F. Very pleased.
Good luck.
Just so folks know, I sold and serviced A/C equipment and tools for 20 years while with Snap-On. Just saying so there is a feel for what I may or may not know.
The owner wants to stay OE stock, so the R12 system stays. We discussed this. He knows that R12 is running about $50 per small can or $50/lb from a machine at a shop. As for 32 degrees at the vent ---- WOW !!!! You SHOULD be "pleased".
BTW, while demoing a charging station I discovered that vacuum testing an A/C system can provide a false sense of "security". A system held 29" for over 15 minutes. After about a half pound of refrigerant went into a 3 pound system there were audible leaks. Bottom line, A/C systems are under pressure everywhere and vacuum can suck leaky spots tight !!!
The owner wants to stay OE stock, so the R12 system stays. We discussed this. He knows that R12 is running about $50 per small can or $50/lb from a machine at a shop. As for 32 degrees at the vent ---- WOW !!!! You SHOULD be "pleased".
BTW, while demoing a charging station I discovered that vacuum testing an A/C system can provide a false sense of "security". A system held 29" for over 15 minutes. After about a half pound of refrigerant went into a 3 pound system there were audible leaks. Bottom line, A/C systems are under pressure everywhere and vacuum can suck leaky spots tight !!!
BTW, if this car (72 pre-L) has a sight glass, I may do the work myself. R12 manifold sets are available. I might need a vacuum pump.
quote:Originally posted by bdud:
in the end and got 32 degrees F at the vent with ambient at ~90 degrees F. Very pleased.
Good luck.
If your air temperature is 32 degF your evap coil temp would probably be 10 degrees less around 22 degF. That means your AC system is actually an ice machine. I would recommend you recheck your refrigerant charge before you cause serious damage to your system.
T.Solo is on to something. If the air is measuring "freezing", that is what will happen to the evaporator, and it will get very wet in the car when it thaws. The 32 deg reading is a) amazing, and b) TOO low.
R12 will get that cold but 134a will only get down to 40 to 42. Doesn't freeze up the coil as much as r12 does.
The lowest temp we measured at the compressor was about 30 degrees F at 2,000 rpm. If I am not icing up the evaporator (though I did not do a visual), mixture of humidity / temp, windows open, then I am happy. The drain tube was certainly pouring out.
All new pipes, new Sanden 508 compressor, using a large Vintage Air Superflow condenser up front with 2 large sucker fans. R134a worked for me.
All new pipes, new Sanden 508 compressor, using a large Vintage Air Superflow condenser up front with 2 large sucker fans. R134a worked for me.
The important temp is what is blowing out of the register.
Take a meat thermometer and stick it in the duct vent.
Traditionally R12 can give you about 32 degrees there. R134a maybe as low as 39.
That's the important temp. That is what is blowing across the condenser.
You don't have to change anything going to R134a. Just put it in and it will work.
When it first came out as a substitute around '93 or '94, the instructions said it was not compatible with the R12 oil and the condenser needed to be enlarged.
I'm not arguing that those instructions are incorrect, I am saying that after using R134a in all my cars, including my 68, R134a works fine.
Haven't even blown a compressor head gasket or a hose because of the higher pressure...not yet anyway and it has been 20 years!
Take a meat thermometer and stick it in the duct vent.
Traditionally R12 can give you about 32 degrees there. R134a maybe as low as 39.
That's the important temp. That is what is blowing across the condenser.
You don't have to change anything going to R134a. Just put it in and it will work.
When it first came out as a substitute around '93 or '94, the instructions said it was not compatible with the R12 oil and the condenser needed to be enlarged.
I'm not arguing that those instructions are incorrect, I am saying that after using R134a in all my cars, including my 68, R134a works fine.
Haven't even blown a compressor head gasket or a hose because of the higher pressure...not yet anyway and it has been 20 years!