Ah, useful data I was running the engine with the manifold on and the service line feeding goo. I have a chart that lists both high and low side at specific temp in f and C. The system was showing pressures consistent with the chart, but the charge was low. The IR probe was not used to measure at those places specified.
I have not tried the rest pressure test. Figured it would show what it would but that would not be indicative of useful data. I do know how much goo was injected, as I have evacuated the system, such that there should be nothing left inside prior to beginning the charging. I should be shy 24oz. I did take the car out for some short (under 10 mile) trips and was pretty impressed with cabin temps and cooling. clay > On Jul 15, 2017, at 12:26 PM, fmiser via Mercedes <email@example.com> > wrote: > >> 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