I owned the 85 1.9 (or was it the 1.8 many years back.) As I recall it there should be a metal "tab" at the base of the lens located inside the body of the lens and it is this which moves in and out during focusing to engage with the focussing cam on the lens mount of the body. (This "thingy" conencts to the helical inside the camera and conveys its movements to the camera body. This is necessary as these lenses are true long focal lenght lenses and all of the lenses elements are located sooemwhere towards the front of the lens body. The metal tab is bronze colored and is rectangular but if memory serves me correctly with the corners cut off if that makes sense to you. I think the 135mm has an identical arrangement.
EDIT: If you are saying that the tab exists but does not work, or does not work properly, it may be as simple as a service. I should add that my 85mm Canon had persistent problems focussing at infinity on my Leica cameras resulting in blurry shots from it most times I tried it. Others have had this problem too with this lens (not sure why - soemthingt o do with critical focussing and slight dfferences in the Leica Canon register distance I imagine - but you state that you ahve a problem with a Canon body too.... hmmm ) I am told that the problem I had could be fixed by recalibrating the lens to my camera. I never bothered as at some point I sold miine to a colelctor who wanted it.
