I just went through a head gasket replacement.......and i did inspect the tensioner and changed the piston + tightening rod. I don't think the tensioner is in its best condition, but the belt did tighten down nicely......is there any known test for belt tightness?
as for AC pressure, i am not sure..i just grabbed a can of a134 + leak super sealant. i got the smallest can since i was not sure what will work -if any thing....it worked to my surprise. today i will get one of those readily available kits with a pressure indicator. sure it is not very scientific or the correct procedure, but i am a complete newbie when it comes to AC systems. I did a search and the amount of info is overwhelming.....

any more suggestions?

fan clutch is working fine. the AC used to not engage. yesterday was the first time it did since i got the car.....

__________________
1993 300E, 2.8 M104 .....