Close call and 20/20 hindsight

[Michael Burdick <mburdick@domain.elided>]

I had an interesting experience with the Stag yesterday on the way back
from a local British car show.  I'll try to keep it short...

The close call:  
    On the way home, I was cruising down the Interstate at about 75 mph,
just enjoying the ride.  I had been paying some attention to the
temperature guage because I was heading into a fairly strong headwind and
I was curious as to whether this would affect the running temperature of
the Stag.  To my pleasant surprise, it didn't - the Stag continued to run
with the needle on the temp. guage at it customary position, slighly over
half-scale.
    About one hour into the drive (near home thankfully, as I was able to
call my wife and she brought out tools etc.. to make repairs), I glanced
down and noticed the guage had crept up a little.  Hmmm.  A few seconds
later, I noticed the smell of coolant and that there was a fine spray
hitting the passenger side of the windscreen.  Uh-oh!  Looking down at the
hood (bonnet) I could see trail of liquid streaming back.  Better pull it
over!  Fortunately, there was an exit just ahead I was able get off the
Interstate to where there was no traffic.
    A quick peek under the hood identified the problem.  The clamp on the
lower radiator hose had broken, releasing the coolant.  The hose did not
come off of the connector pipe between the thermostat housing and the
radiator, so the coolant didn't just dump out.  Lucky for me.  It was a
quick job to fix it on the side of the road, and I was able to continue
the journey home with no further problems.  I think I avoided any serious
damage but will keep an eye on things to be sure.

20/20 hindsight:
    The cause of the problem was that the clamp was in contact with the
power steering pump pulley.  The contact weakened the clamp and
eventually, it gave way.  The contact was periodic, and I think it mainly
occured when the engine was hot, and under load.  How do I know this?  
Well, for the last month or so, I had been noticing a faint zzzzzzzzz
sound coming from under the hood.  It changed pitch with engine revs, and
I only noticed it when the engine was hot, and when I was accelerating in
first and second gears. I looked high and low for the source of the sound
but could never find it with the car stationary, even with the engine hot.  
My theory is that the load on the engine, when accelerating in low gears
(and maybe at 75mph into a head wind), caused a slight shift of the engine
on its mounts and brought the clamp and pulley into light contact.  Over
time, this contact ground down the clamp, and eventually it gave way.

A new item on my monthly visual check will be this clamp, and its
clearance between that pulley!

Keep your coolant level up,
Mike Burdick
'72 Stag
Omaha, Nebraska 
USA