Wanted to top off the refrigerant in the AC system, but not sure which is high or low port. Bentley manual not helpful (unless looking at wrong place).

 

If you're using one of the refrigerant cans with the pre-attached hose, the fitting on the hose will only fit on the correct (low-side) port. I can't find a picture offhand, but I'm sure someone else will post one.

 

The low port is higher and further back than the high port. Both have black caps screwed on. As stated, the fitting will only work on the low side.

 

low side is the small one, high side is the larger one. if charging with small can bought from pepboys, have can upright, valve on top, with car running.

 

I know this is an old thread, but if anyone's willing to help out, I'd appreciate a reassurance on this. My husband and I bought one of those kits to see if it's fix our A/C on a 2003 mini coop. The instuctions on the can say it should be screwed on the larger port, however, it only fits the smaller port. Also, the smaller port is actually a littler lower than the larger, though it is set a bit further back from the front of the car. Furthermore, when we actually tried to screw it in place, the pressure reading on the canister jumped into the red zone. All the conflicting information has us worried.

Anyone got and other sources for info?

Thanks,
Laura

 

Not sure what brand recharger you have, but you definitely want to use the low port vs. the high. You say 'screw on', the one I tried just sort of slips on. The low port is parallel to the ground, while the high is at an angle.
If your AC isn't working, confirm that the AC clutch is activating, and check that your low speed radiator fan is working. I ended up replacing my compressor.

 

This is normal assuming the system isn't running. When off, the pressure equalizes on both sides. When it starts running, the low side drops and the high side goes up. The gauge is meant to measure the pressure when the system is running (lower pressure then when idle). Please note those kits are only really useful if the system is actually running and just low on refrigerant. If the compressor or clutch is bad per Eric's post, then a recharge won't make any difference. At least the kit will tell you the compressor is running if you see the pressure drop when you start the AC.

 

I know this is a really old thread, but it keeps coming up in my search results every time I try to research this again, so other people might be searching for this answer too. I have not tried it myself yet, but I was also confused about which port is which, in my case on an R56, specifically a 2009 MINI Cooper (non-S). I do have a Haynes manual which has a photo, 3.13, the caption for which says "The low-side charging port on Mk II models is located in the right-front corner of the engine compartment, near the oil dipstick." That is the one I would have expected to be the high-pressure port, but apparently not. Verify your model and use this information at your own risk!

 

Very old, but I have just done my 2013 R60 Countryman. Low pressure port is in the front LHS of the engine bay, right near the oil dipstick.