ac charge

[arkninjazx9]

I'm trying to charge the Ac on my 87 MJ.....there are two caps covering two long square things in front of the connectors for the freon on the compressor. they are under two caps...do you need to turn these or something to get the system to accept the new refrigerant ? help these things are baffling me.....

[airspeed]

First you have to determine what your AC system is charged with, R12 or R134a. If it is original it will be charged with R12, in 1995 they switched to R134a. The two freon systems are not interchangeable.

 

The only kits you can buy at the auto parts store are for the R134a system. If you want to recharge with R12 you will have to go to a licensed shop. The system can be converted to R134a but it is expensive to do it right, they would have to install a new filter/drier and change the seals.

[JeffN]

If it still has external threads where you charge it is still R-12 and you need to be licensed to do that system.

You should only charge it thru the low side port (the one with the fatter hose).

And you will have to open up the port with a wrench to accept freon into the system

[Eagle]

And you can't mix R-12 and R-134 in the same system. They are not compatible.

[DREDnot]

all the service manuals show those valves in cutaway so you can see how they operate.

all the way in clockwise,front seated,isolates the compressor from the system... to remove it.

 

all the way out counterclockwise,back seated, is the normal operating position.

 

half way between the two, mid position, the gauge port is open. this position is used for charging, discharging, evacuating, and checking system pressure.