How to add coolant to my truck? do i put the freon in the port on the little silver can or the one below it with the lit skinny pipe? Have i messed up if i let what seem to be freon out of that little pipe? I lost the top

There is a port to add coolant under hood on driver's side nearest driver. Pipe with cap has "L" on it.

the low pressure port is usually in the accumulator (aka receiver/drier) which is the large silver cylinder on the passenger side. If its not there, sometimes it is on the a/c compressor on the marge diameter hose/line. The high side is on the smaller line near the coolant reservoir. The low side is the one you want to fill with.

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

All you need to do is to trace the thicker piping of freon from the compressor to the low side port. The thinner piping is the high pressure side.

Add freon on the low side port:

The low side port is located on the thicker piping vs. the thinner piping.
It may have a black or blue cap.
The hose, don't worry' won't fit anything but this quick connector,

It does not contain Freon. It contains R134a refrigerant. You add it at the low pressure port. There is a blue or black cap on the connector. The low pressure pipe is the larger of the 2 metal pipes.

half can is low, possible cause is that fill port is clogged happens when u put sealer in sometimes, but it sounds like your system is under charged check pressure, if no reading port is clogged change port, low reading add freon,

You need to evacuate mositure with a vacuum pump and then add a can of r134a with oil in the can. Then add more cans without oil. Up to the amount on the decal under the hood.
The low side charge port is behind the passenger fender well. Remove tire and the 7 fasteners holding the plastic fender liner in.

You need to locate the low port on the AC.

You recharge the AC connecting to the low port.

You find the AC low pressure at the top of the compressor. Near the compressor you find two ports, the high port and low port.
You can follow the compressor line to reach the port.

To find out which one is the low port, run the air conditioner for a couple of minutes withthe engine on.
Then turn off the care and touch the lines from compressor to the two ports , often covered with plastic caps. Only one of the pipes will be cold, the line that is cold will lead you to the low port.

if u didnt find your freon port, the low pressure side is on the passenger side next to the firewall. Notice where the strut is bolted and look a little further in. Hard to see and hard to get to. Hope this helps..

CALL THE CAR DEALER AND ASK THEM WHERE IS THE VALVE TO FEED THE FREON AND FIND OUT WHAT TYPE OF FREON.