[casmakinc]

Replaced water pump, started it up and still leaking by alternator. Took it for a test drive, no leak. Another test drive, the leak is back. Any suggestions?

 

[rjacket]

Only reasons would be faulty part / gasket or incorrect tighten sequence or incorrect torque or dirty sealing surface.

Since this is the internal water pump, you would have to take apart to fix.

Is leak minor? Is replacement a Motorcraft part with updated design? Was this a diy or shop performed job?