i go with njf207. i have been doing a/c for 20 years and when r134 came out every said how different it is . i have to say that after working with it for 14 years that it is so close to r12 in pressure that you need not worry about your guages working with r134. the only time i every saw a 10 to 1 ratio is on large trucks when the condenser fan did not engage for some reason. on cars and light trucks if you have proper air flow i have seen on average readings form 20-45 on low sidwe and 150-225 on high side. when charging with 12 or any other gas on thing remember is that any a/c comp. is meant to run at 10 to compression ratio or less.

one question though, how much 134 would you have to inhale to make you sick?
i have never heard a true story of someone becoming ill from 134, lots of my wife's brothers friend stories but no one on one experince.

 

R134a is not toxic but it is heavier than air so it displaces air. Breathing enough of it would suffocate you because your lungs were full of 134 instead of air. I would say it is highly unlikely to die from the stuff unless you were in a room with no ventilation and snorted/breathed it directly.

 

It was worth a try thanks and if you hear of anymore good deals let us all know

 

You are "dead" wrong on this. The Airforce did a test in 1999 on it it to simulate the effect of a leak in a enclosed compartment and found that the average charge on a R134 system contains 3 to 5 times the amount needed for a lethal dose in a unventilated compartment. (and it is not from lack of oxygen) They almost lost there test subject and had to use a emergency team standing by to save him because he suffered for its effect and at a much lower level than they thought it would happen at. Dupont of course has little comment about its toxicity and so most assume it is safe. R12 is inert and the only way it could harm up would be if it dispalce all of the oxygen, not so with R134. (R134 is even deadlier in a fire)

 

the toxic part about 134-a is true, BUT only if is burns. then it turns into phosgene gas, which is a nerve agent.