A/C Fill Freon Fill Amount

If you can't find the spec just fill it until pressures are correct

 

Ya. I would add a little more. Our day cab Pete 365's take 44oz

 

3lbs if you have a Sanden, 4lbs if you have a CCI compressor.

 

that sounds pretty close to correct pressure wise if charging on a relatively cool day. keep in mind that pressures will be higher on a hotter day than on a cool day.

if it happened to be fairly hot out when you charged it i might add a touch more Freon. charging by pressure is not perfect but you can get the charge pretty close. i don't have a way to weight my Freon so i normally just charge by pressure so you should be fine just charging by pressure in absence of knowing the Freon amount the system holds. i really should get some kind of scale to put under my refrigerant bottle.

overcharge can effect system performance as much as undercharge so sometimes you have to resist the urge to "add a little more"

 

check your pressure after the system has sat for 8 or so hours, the pressure should be very close to the ambient temp, 70 psi at 70 degrees F . if it will cycle the compressor and kick the fan in you are really close, overcharge creates extra load and lots of extra heat

 

When dealing with the unknown or the just does not do right units I charge by thermometer with in allowable pressure levels. Open all the doors and set unit to fresh air if applicable. Put therm. in outlet vent with a known low charge and add freon about 4 oz.at a time. Allow time for system to stabilize after each addition and check temp.( takes a few minutes 3-5 ?). Keep adding intell the temp. increases and back up.