Chances are, the carbon seal to brass face developed a rust spot. When
sitting, the leak began. With driving, the spot was wiped, and the leak
has temporarily stopped. If you saw the leak from the grease exit slot
on the bottom of the water pump housing, then it was the seal. Since
you do not have a leak at this moment, why don't you wait to confirm the
leak at this location. Another source could be the water outlet housing
at the front of the head. Many were made of aluminum, and do corrode.
Zerex, or some other coolants, will seal the leak for short amounts of
time. A leak would trickle down, onto the water pump, in which case, it
would appear as a water pump leak. I have also seen water leak past the
two bolts, that hold the pump to the block. The bolt holes go into the
water, and water can weep past the bolts. Use Loctite (either
threadlocker or PST on these threads).
|