That's why I love having an ac machine. I pull it out, and charge with the 
correct amount by weight.

Sent from my iPhone

On Jul 15, 2017, at 2:26 PM, fmiser via Mercedes <> 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.
> _______________________________________
> To search list archives
> To Unsubscribe or change delivery options go to:


To search list archives

To Unsubscribe or change delivery options go to:

Reply via email to