06 International 8600 day cab Air Conditioner info needed

The best way to fill a CCOT system is to place your hand on both the inlet (low side of the pipe past the orifice tube) and outlet pipe of the evaporator. With the compressor running and fan moving air across the condensor, fill the system into the low side quickly with liquid (as long as the charging port isn't right at the compressor) by turning the can upside down.

The absolute second you feel the outlet pipe become as cold as the inlet pipe, stop charging. The evaporator is flooded properly.

It happens quickly, so you'll know.

To get the fan to run constantly, unplug the fan solenoid. Watch your high side while charging. If it shoots up sky high and the compressor stops before the evap outlet pipe gets cold, STOP charging, you have another problem.

I charge CCOT systems on trucks this way because you never know if something in the system has been modified. Maybe a larger condensor, longer hoses, etc. If you under charge, you not only will have poor cooling, but risk burning up the compressor from lack of oil.

Now if the evaporator is flooded and the outlet pipe is cold and you still only have 68 degrees at the vent, you may have a blend door partly stuck open. You should easily be able to get 40 degrees below ambient out the vents, to a low of 40 degrees. Try shutting off the water flow to the heater core and putting the controls to recirculate. If it that works, the blend door is stuck or misadjusted.

Also check the evaporator fins to see that they aren't plugged with dust and hair.

 

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Start at the fan hub and follow the air line to the solenoid. They are usually on the firewall somewhere.

Most are failsafe, meaning that they require 12 volts to apply air pressure to the hub to keep it disengaged. No voltage at the solenoid or no air pressure on the line will cause the fan hub to engage.

 

A/C I know... air brake systems, not so much. I'd post it in a separate thread.