7140 A/C

Iv got an 7140 case tractor the A/C isn't cooling...iv already repaired the leak which was coming from the Schrader valve.
I simply removed the Schrader valve from the old r-12 line fitting and installed a new R-134a fitting over it.
My question is...the light in the cab with snow flake next go it. WHAT DOSE THE LIGHT MEAN ?

the light means the compressor is not on,thermostat is not working,or safety protection switch(high press. or no press)with the tractor not running turn switch on turn fan on change thermostat switch you should hear compressor lock up.could be several things,hard to cover all.

I'm sorta self taught on this a/c stuff but there is a ton of info online. The light is the a/c low system pressure indicator. It will come on when the a/c system has 3psi +/-
and protects the compressor from running without oil.

What does your gage set system pressure read? High and low pressure gages will be the same when the compressor is not running.

Find the leak and fix it, generally good practice to replace the expansion valve and drier if the system has been low or open to air for any period of time. (moisture in the
air ruins the drier and that leads to plugged or stuck expansion valve)

I just did the air in my 7140, autozone rents/loans out a vacuum pump, gage set and flushing tool. I was surprised how much crud was in the evap and the line between the drier
and the exp valve (the valve was plugged and didn't work). Autozone sells the flushing fluid, but some online use mineral spirits. I did the first flush with min spirits, then
flushed that out with the a/c flush stuff.

Toughest part of the job for me was getting the old valve out after lifting the cab off. The drier is under the floor near the door, above the battery and is fairly accessible.
Flare nut wrenches would be nice but not absolutely required.

Get the right o-rings, R134 systems use HNBR material rings, or just get them from the dealer when you buy the other parts.

Good luck, but if you're not comfortable with doing this find someone that is and help them. It isn't hard work, just different thinking...

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Talked to case dealer today...said it was 25-35 psi low side...200-225 psi high side
This is ambient temp of 80 degrees

Pressures sound about right. With the engine off, you can unplug the high and low pressure switches, don't recall if
they're normally open or closed, and force the clutch to engage, should hear it click, when you adjust the temp dial in the
cab.

If it does click, then you can fire it up and run it briefly to watch the gage pressures. If it doesn't click, check wires,
fuses, etc. Beyond this, I'm not going to be much more help.