tx Larry,
I started a conversation with the folks in Modena/IT per Eugenious link. Let me see what they come up with..I have NO idea on the push rod diameter as the vacuuum booster has no more a type stamp. ON the Master cylinder there was the US Bath tub including the ADAPTER 4 to 2 bolds I did replace them!!!
..but as you said this is again independent on the Boster problem itself.
Question remaining: Is there an issue on the PRECISE length of the push rod as I chnaged to a Europen Master and NO ADAPTER 4 to 2 ? I did check the binding gap but NOT on the last 1..2 mm ..