Might be time to look at a double belt on the Alt. (do they make those?)
Sounds like EXtreme tension on the alt. is playing havoc with the WP bushing/bearing hickey!? Don't axe me how I know...
6s6

MS wrote:

I installed a new Flowkooler pump on my 427 stroker the week before the bash.  I drove a total of around 750 miles and now it is leaking again..  I did not lose any apparent water from the radiator on the trip.

Granted, my alternator belt is pretty tight to keep the 3G alternator belt from slipping, but this is ridiculous.  These pumps have a one year warranty.  I hate to have to keep working on stuff that should stay FIXED.

MS - I have a Flowkooler on my 351W with over 9K miles in 12 years with no issues.
An item I'll ask is are you using anti-freeze as it provides lubricant for the water pump's shaft seal.  Years ago, I ran just water and the water pump started leaking a short time later.
 
Regarding the alternator V-Belt, I had issues with replacement 3/8" wide V-Belts (Gates 25-7400) for the alternator.  I had to make this V-belt tighter than I ever remember having to do in my past and it still didn’t stop the squealing, usually just on start-up.  I changed pulley on the alternator with no success.  I did fell that the belt was riding deep in the pulley groove and thought maybe the belt was bottoming out in the groove, this could stop the belt from getting any tighter in the groove.  I found that the Gates 25-7400 belts are made to mm dimensions and are slightly narrower than 3/8”.  So, last year I installed a 1/2'’ wide belt (Gates 25 9400) that appears to me to sit better in the pulley V groove.  I have not had a squealing problem since this installation.
Hope this helps
 

The flowkooler pump is a gmb with a billet machined, highly improved impeller.  I am using anti-freeze. I have a 4” BOSS 302 steel pulley. Also steel wp pulley and March aluminum crank pulley. The 1/2” belts seem to ride too high in my pulleys for my taste, so I use the 7/16” version. No squealing now, but leaking pump.

If any changes are made, I will probably convert to a serpentine belt system.

Thinking of selling the car and letting someone else enjoy it. I have sights on another one... or two.

Electric cooling fans relieve the need for super tight drive belts........cause without that big old airplane prop...one less thing for the engine to spin.
Jus thought I'd  "throw-that-out-there"!!!
6sally6

MS wrote:

Thinking of selling the car and letting someone else enjoy it. I have sights on another one... or two.

Man! I never thought I would hear you say that. I need to sit down after reading those words and wonder if you might need to go take a nap and reconsider things (ha, ha)

red351 wrote:

Anytime I super tighten (let say an a/c) belt, it turned inside out just before it turned in to cotton. Cheap as I am, I've rebuilt a few w/p  to save a penny and peace of mind it's done right. Them barrel bearing are tough. A seal would fail first most times. So I would say a seal or cracked housing.

Now I'm going to get myself in trouble here and say, maybe it's leaking somewhere else up front. 

Maybe you are right. That drip IS coming from the harmonic balancer, not the water pump...

MS wrote:

red351 wrote:

Anytime I super tighten (let say an a/c) belt, it turned inside out just before it turned in to cotton. Cheap as I am, I've rebuilt a few w/p  to save a penny and peace of mind it's done right. Them barrel bearing are tough. A seal would fail first most times. So I would say a seal or cracked housing.

Now I'm going to get myself in trouble here and say, maybe it's leaking somewhere else up front. 

Maybe you are right. That drip IS coming from the harmonic balancer, not the water pump...

 
Time for jock itch spray!