Hi. Every summer, the cold has been gradually diminishing.

Decided to buy a cheap 12+2 oz. R134a gas can with dispenser hose (no gauge)
No expectations to do a professional job with precise dosage, nor purging the existing gas, nor going for a hunt of a tiny, tiny leak somewhere, (which can be the normal leak by the compressor shaft).

Plan is : If things improve noticeably; then think of a second 14 oz can at a certain point. Do you see anything wrong with that rationale ?

What bothers me is the amount of air inside the dispensing hose. I would like that air not to enter the system. Purging its air immediately before connecting the hose with a brief press of the button ?

Seen in other vehicles an "accumulator" with a sight window. Is there one on the Disco ?

 

No site glass on a disco

 

For best cooling you need to draw a vacuum before you pull the trigger. If you search for redneck air conditioning I figured out how to do that on the truck. Basically you just need an extra freon hose and complete disdain for the ozone layer.

 

If you use AC/Pro, you attach the hose to the vehicle side first and it will charge the hose and gauge with Freon from the vehicle. Then you attach the can of Freon so there isn't any air in the system. I topped mine off last summer and it worked great.
AC PRO Instructions | AC Pro

 

I'd probably consider putting some dye in too; that way you can find the leak if it (even if it isn't worth fixing).

I charged mine a month or so ago. I had replaced a hard line that snaked from the drier to a connector joint; one of the clamps had rubbed a pinhole leak.

The PO had put dye in at some point and it was pretty obvious where the coolant had leaked from. After I vacuumed and charged the system, it now cools great, but I now see some dye coming from the two hardlines right on top of the compressor, which should just be some O rings.

Of course, a sniffer will also find a leak too, so that might be an option too if you want to find the source of the leak.

 

There are little o rings under those squarish looking ends of the hard lines.