Sudden Transmission Oil Leak 1976 Fleetwood Brougham

[Roger Zimmermann]

Yes, Philippe, I know it was you, but I did not remember your ID name for this forum! I should think at the French word "filou" (you are not such a bad guy, not at all)!
I think that's a preference from the designer: on the '56 Hydramatics, there is also a tiny hole and an O ring. And from 1957 to 1963/64, no more hole! As you wrote, the oil is here only when the vehicle is not used for some weeks; in normal use, the lever is lower than the tiny hole.
As I wrote: if this is leaking again, a screw will be installed.

[Dave CLC#16900]

Dave CLC#16900:  There is an o-ring seal on the vacuum modulator, which is replaceable, that can leak, but most often the diaphragm inside leaks and the engine then sucks out the ATF and burns it.

Hi Chopper1942, mine was leaking both internally and externally according to the trans shop.  It was solved after they replaced the modulator.

Dave