I think he stuck the tube in the palm of his left hand, and while making a fist with his right hand, firmly but not harshly struck the tube with the lateral side of his fist...
Tech, so the sub cas does indeed remain active all the time, but it is used more as verification for the main CAS?
Maxnix,I think he just has a bad case of leaks all over the engine compartment- or he is using the RTV to pre-emptively treat future problem spots- both the fan shroud and the electrical harnesses are known to be very prone to leaking on the '92 Q!.
(Jesda, just kidding man - could'nt resist ! A good DIYer with a shaky RTV tube beats the heck out of a trip to the shop for a simple project!)