Pooled coolant/steam surprise

["Dan, Marilyn, Anathea & Phillip Patzer" <bmrfamly@xxxxxxxxxx>]

Gentlemen
  Time and again I hear from owner's returning to a parked car that was
normal when they left it, but found pooled coolant or a steaming mess upon
return.
  The cooling system reaches it's highest temp and pressure 10-20 minutes
after shut-down.  The cooling system by design is a heat sink.  Upon
shut-down, you have all of the residual heat of the motor, but no way to
dissapate it.  No air blast thru the radiator from either vehicle movement,
or fan motion.  Couple this with the lack of circulation of the
super-heated, hyper-pressurized coolant because the water pump stopped when
the engine did, we just hope the high pressure release devices at the
radiator cap and water pump seal can handle it.
  Over-filling the cooling system can exacerbate this situation.
Calibrated Air cushion is used to absorb the post-run over-pressure
moments.  Without this air cushion the non-compressable, yet expandable
coolant will test the hoses, etc. on each heat-cool cycle.

 Dan Patzer the CyberWrench from BIMMERS ONLY
72' tii touring   K1200LT   85' 732i   R850R
http://www.nwlink.com/~bmrfamly/   425-259-3601
 O.E.M. parts, Independant service since 1967
 12724  Marine Drive,  Marysville, Wa. 98271

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