> clay wrote: > I evacuated the system once more (it had been tested overnight) > and did a refill. Well, sort of. It calls for 3.3# of R12. > There is a pressure/temperature chart that gives pressures based > on outside temp. Using that, I reached the required pressures, > but am short on volume?
At rest pressure CANNOT be used to figure out how much is in the system. Once there is about 20% change, the at-rest pressure will match the chart. It won't change until thy system is over-charged. That's the nature of gas. (not gasoline/petrol) With the compressor running, looking at the low side pressure can give a pretty good clue as to the change. The high side doesn't tell much about charge. Weight is the most consistent way to determine change. That's hard to do on an partly-changed system 'cause it's hard to weigh what is inside. Without a machine to remove it all, (and scrub it clean and weigh it before putting it back in) the only way I know is to monitor temperatures in the evaporator. Checking inlet and outlet temperatures can be enough. A no-contact IR thermometer is handy - but remember most of those are calibrated for black, not aluminum, surface. Out of the compressor should be hot. Out of the condenser should be quite warm. After the expansion valve and inlet to the evaporator should be cold. Out of the evaporator should be about the same or a bit colder. _______________________________________ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com