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Discussion Starter · #1 ·
I've not seen this problem with any other car I've owned in 50+ years of driving.
My A/C seems to work just fine, as long as the car is moving. A few seconds after I come to a stop, it continues to blow air but it stops being cold air.
Shortly after I start moving again, it starts working.
I know I could just take it in to service for analysis, but I thought I'd see if anyone here has a clue before I do.

Thanks
 

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When your RPMs increase, the AC clutch runs faster, creating more pressure. This typically happens of the system is undercharged (not enough coolant) causing the pressure switch to open at low RPM.

I have also seen this happen when the AC System is overcharged (too much R134A). If there is too much, the ratio between the liquid and gas R134A is too large and the system can’t operate efficiently.

If far too much is added, the system will trip the pressure relief valve which sounds like a machine gun going off in your engine compartment and blasts R134A all over and into the environment which isn’t good.

Many “do it yourself” remedies will tell you to just “add a can of R134A. It’s best to put the correct amount into your AC system for optimum cooling.
 

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He's not mine
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9,617 Posts
Discussion Starter · #4 ·
When your RPMs increase, the AC clutch runs faster, creating more pressure. This typically happens of the system is undercharged (not enough coolant) causing the pressure switch to open at low RPM.

I have also seen this happen when the AC System is overcharged (too much R134A). If there is too much, the ratio between the liquid and gas R134A is too large and the system can’t operate efficiently.

If far too much is added, the system will trip the pressure relief valve which sounds like a machine gun going off in your engine compartment and blasts R134A all over and into the environment which isn’t good.

Many “do it yourself” remedies will tell you to just “add a can of R134A. It’s best to put the correct amount into your AC system for optimum cooling.
Thanks, and to jwight too. I like your answer because it's the cheapest fix, LOL.
I bought this car used 18-months ago. I'll have the coolant checked.
 

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The A\C ports on the 451 are a pain to get to. They (451s) were known for the sauce leaching out over time. On my first one I bought a meat thermometer and stuck it in the vent, on max AC and added R134a until the temp was 45-50 degrees colder than ambient. If you watch on the ghetto gauge for inserting the Freon, there are ranges to assist in the process. If you overpressurize the system, the evaporator with turn into an iceberg. It's still WAY cheaper than a $tealership!
 

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He's not mine
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9,617 Posts
Discussion Starter · #6 ·
The A\C ports on the 451 are a pain to get to. They (451s) were known for the sauce leaching out over time. On my first one I bought a meat thermometer and stuck it in the vent, on max AC and added R134a until the temp was 45-50 degrees colder than ambient. If you watch on the ghetto gauge for inserting the Freon, there are ranges to assist in the process. If you overpressurize the system, the evaporator with turn into an iceberg. It's still WAY cheaper than a $tealership!
I definitely am not making a 600 mile round trip to the nearest dealer. I'm sure a local mechanic can handle the job.
 

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I've not seen this problem with any other car I've owned in 50+ years of driving.
My A/C seems to work just fine, as long as the car is moving. A few seconds after I come to a stop, it continues to blow air but it stops being cold air.
Shortly after I start moving again, it starts working.
I know I could just take it in to service for analysis, but I thought I'd see if anyone here has a clue before I do.

Thanks
Sounds like its low on freon
 
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