David,

the "hack mechanic" that put the metal insert in the plastic pipe was VW
or whomever made the pipe for them

it was designed that way

the metal piece was to prevent the pipe from cracking under the pressure
of the clamps and to form the bead that helped keep the rubber hose on
the pipe

over time they do come loose and this is a problem with those pipes

lots and lots about this in the archives over the years

so you are really playing with fire by running without the metal insert

I don't have anything saved on my hard drive about fixing the metal
inserts so that they stay in place though there have been suggestions
about this in the past - I just never had the problem.

However, a quick search for posts containing the header "coolant pipes"
and written since January 05 turned up lots of hits in about 20 seconds
and a thread that started with this post.

http://gerry.vanagon.com/cgi-bin/wa.exe?A2=ind0511C&L=vanagon&P=R10973

looks like it discusses the problem and solutions.  Moving back in time
would reveal dozens of other threads about this problem and possible
solutions.

You need to take care of the weakened coolant pipe you created by
removing the metal insert.

Sam

--
Sam Walters

Baltimore, MD