ASC Industries, Inc
Coolant pump replacement
Seal wear occurs when grit gets between the stationary primary ring and the mating ring.
adhesive if it's recommended. When using adhesive, make
sure none gets squished to the inside of the pump. Even a
small glob of sealant floating through the cooling system can
interfere with the thermostat.
Bolt torque matters. The water pump on a Toyota 3.5L V-6
engine has a paper gasket and is held in place with 16 bolts,
and there is a torque sequence and two different torque specs.
The Chevrolet Aveo water pump is held with 3 bolts torqued
to the same value and sealed with an O-ring. Both types of
seal will be subjected to thousands of heat cycles, and proper
bolt torque is critical to maintaining a good seal. Make sure to
clean out the bolt holes before installing the pump, and don't
forget to apply sealer to any bolts that thread into a cooling
On engines that drive the water pump with the timing belt,
it's common to replace the pump and the belt at the same time.
That's not just to save the customer from having to pay for the
same job if the pump fails later. All pulleys and bearings in
the whole belt drive system affect each other. Even on V-belt
driven pumps, any pulley or idler what's not turning smoothly
or in the same plane as the others can stress the bearing on the
new pump. The bearing is designed for a specific amount of
stress imparted by belt tension, which is why most belts are
tensioned with a spring or some other automatic tensioning
ACTION * March 2014
Table of Contents for the Digital Edition of ACtion Magazine - March 2014