92 spider air plenum: rubber hose becomes loose

["Church, Marc" <Marc.Church@domain.elided>]

I've got a 92 spider with the stock Bosch Motronic setup.
There is a large rubber air tube that connects the F.I.
unit (on top of the air box) to a hard plastic tube on
top of the engine. The connection between the rubber tube
and the hard plastic tube comes loose often.  I've tightened
the hose clamp many times but the hose always gets loose. I've
also noticed that the metal (reinforcing?) ring inside the
hard plastic tube slides out. I'm not sure whether the 
problem is due to the hose clamp loosening up, and then the
ring sliding out, or it is the ring sliding out first making the
hose clamp unable to stay tight.

Has anyone else had this problem?  The rubber hose was 
recently replaced with a new one.  The hose clamp is the
original italian-styled clamp, and appears to be in good
condition. 

I'm tempted to try some adhesive on the metal clamp to see
if it will stay put inside the hard plastic tube, but I
don't know of any good candidates off the top of my head.

Thanks
Marc
--
to be removed from alfa, see /bin/digest-subs.cgi
or email "unsubscribe alfa" to majordomo@domain.elided