A/C System Pressure

[RichardP]

Does anybody know what volume of gas the Cerbera a/c system takes or what pressure it should be regassed to?

I understand that the pressure switch inhibits the compressor if the system pressure is too high (i.e. over-gassed). I had the system re-gassed yesterday but the compressor will not run (it will with a direct supply to it). The system has worked fine for the last 5 years until a hole was worn in one of the hoses and I lost all the gas. Having replaced the necessary components and had it re-gassed, it doesn't work, hence I suspect the pressure switch because if I by-pass it the compressor runs OK.

The place that re-gassed it weren't sure how much gas to put in so if I can find out the correct figure, I'll check with them.

Thanks, Richard

[shpub]

Talk to the factory and they will tell you the weight of gas that is needed for the air con. Ask nicely for the service dept and say "I'm standing next to a nice air con man who needs to ....."

[RichardP]

The answer is 0.6kg (thanks to Lesley at TVR) but the a/c chap confirmed that's the amount they put in, so it looks like the pressure switch is faulty.

[SXS]

You actually use the aircon????? Damn, I cant remember when I last used it....

[RichardP]

It actually failed when we were in the middle of a 1900 mile trip round France and the temp was in the mid-30s. If you are driving all day the heat soak from the engine makes everything very hot - I think even you'd want to use it then! And it's very efficient at de-misting the inside of the windows in the winter.

Anyway, it's all sorted now. It was the 4-way terminal on the pressure switch that wasn't making proper contact. I'd cleaned the corrosion off but in doing so had inadvertently opened up the female parts of the connector. The a/c has never been so efficient!

[Julian64]

I tend not to use Kg as a method. I have a temperature probe which I stick in the vent. The car gets to run for a while and then I add gas slowly (with oil) until the temperature plateaus low. No point in adding more coolant after this. P.S. make sure your thermostat (under dash) is turned down low.