What is the Capacity of R12/R134A the system calls for, TOTAL ?
What is contained within a can of your topup R134A/substitute?
IF you overfill the system without knowing ... it can have strange effects, none of which I have experienced first hand but have suspected on at
least one car, that we sent to a Freon recycler/flusher before we even touched the car. You know the kind of car that comes in and the cust
states they topped it up? Then the questions begin and you want to know more before you contaminate your machine and every other fill up for
other customers who would get their R134a fill following repair from your now mixed tank.
Here is a link to the AC performance test procedure - this is the factory manual 89-93 Galant IIRC:
Chapter 55
http://www.lilevo.com/mirage/89-93%20Mitsubishi%20Galant%20Eagle%20GTX%20BE%20Service%20Manual%20.PDF/89-93BE.PDF
Oddly enough they used a can refill procedure but some of the aftermarket cans, are a pierce pin style can after attaching, and remove the whole kit once you reach a max cold recorded temps at the specific dash vent during the fill but it can be very easy to overfill I think. Very unspecific, when machines can do the fill to well within the tolerance of what the fill intended was, as set to on the machine.
They mentioned to check the sight glass during the fill - this can indicate the presence of air bubbles, which can be an indicator of low charge, but by the same token can be 100% misleading depending on the temperature at which the view is made!!! I just did some reading and unless I am holy wrong, at certain low and high ambient temps you can get some separation inside a completely filled (READ proper charge level) system, so those bubbles would only go away inside of a set ambient temp range. For those reading this, be aware of this condition.
I would like to know if your AC fan starts the moment you engage your AC system ? I am trying to find the description and operation for the GVR4 AC system, as my Colt was similar but was not wired the same way, nor operates exactly the same way under all circumstances even though it has a resistor setup in use. Essentially my AC fan comes on immediately, when the AC is selected and clutch engages, and under higher pressure in the system - reaches a switch point - at which the fan gets moved to a non resistor setting and is allowed full battery voltage. I am unsure of how much a pressure change is read between the chart for R12 system charge and what occurs with R134a or substitute in the system, so that is in regards to what you should see at your high and low side connection points for gauges/fill/removal. Also, you have to be sure of how much system oil is in play both when you the system was operating properly (for the last few years) and now that you have had a blow off condition at the compressor - this is where most of the oil sits, but not all. You have definitely lost a portion of your system oil.
It also seems that for a fill of R134a, you may have to fill to a percentage of the complete system refrigerant capacity due to the pressures that R134a works at, or so this particular site is commenting on:
https://www.aa1car.com/library/retrofit.htm
I would honestly like to know what people are filling their converted system to, and at what pressures they operate. The gas is supposed to operate in certain pressure ranges, otherwise the change of state is insufficient (just like a non-working metering valve or blocked/partly blocked orifice tube).
I relayed system pressures from OEM R134a equipped vehicles, so I 100% want to be correct on the pressures you SHOULD be seeing with your converted setup.