At 02:32 AM 2/24/2011, M. Jade wrote:
>Thanks a lot for everyone's quick reply to the question. The coolant
>hose is original. It was never replaced despite the thermostat has
>been replaced twice and the hose was disconnected and reconnected
>many times. I noticed that the hose is not as flexible as when it
>was very new. But it is not hardened to a point to need replacement.

You're talking about a twenty six year old hose here that's been
subjected to innumerable pressure/heat cycles.  VW hoses are of very
high quality but they do have their limits, and the limits I've
observed (n of approximately ten) have all but one involved a roughly
3/8" long slit in the longitudinal direction of an old but apparently
healthy hose.  No loss of flexibility apparent in any case.  In the
anomalous case the hose (still flexible) split transversely at the
nipple.  It was shortened a half inch and one week later split
again.  This was the odd hose on the 2.1l that has a skinny end going
to the ring manifold surrounding the engine hatch and a very short
fat right-angled end going to the engine.  The failure was at the engine.

My point is that these hoses are way past their intended service
lives, no matter what they look like.  I'm sensitive to this, since
the '89 I got a couple years ago had four coolant blowouts in the
first four months of driving, all in hoses that looked and felt perfectly good.

Yours,
David