I was pouring in coolant for the first time in my new engine tonight. I was getting all giddy, ready to fire her up, but then the coolant just came right out of the wheep holes in the water pump. The water pump was used on the old engine, but I replaced both gaskets using RTV sealant. I don't see why it would start now, and not before. Am I just missing something here?

 

If your leaking out the wheep hole the seal in the water pump is going bad. With a new engine go get a new pump, you don't want to take the chance of overheating that new engine. That pump will only leave you stranded somewhere. My 2cents

 

It's not just weeping, it was flowing out the top and bottom holes. Any idea why this would have just started after the rebuild. I definately didn't have that big a leak before.

 

The seal dried out while it's been off the engine.

 

Very good, thanks. I'll buy a new one.

 

When I put in the new 300-6 in mine back in Feb, it looked like the water pump also but after carefully following the water trail it turned out that we did'ntscrape the thermostat housing off good enough and some gaskett was left.Check that and your
block for left over gaskett where the pump bolts on.

 

Alway wise to install a new or rebuilt water pump, when an engine is replaced. Overheating a remanufactured engine will void shop/factory warranty. Also a good idea to fill system with water only at first, to make sure there aren't any leaks in the system. Allow engine to cool down completely, pull lower hose to drain, reconnect, top off with coolant.
The engine shop that rebuilt my 5.8L, installed a "dime sized" heat sensor, in the center of each new freeze plug, located at the back of both heads. If "sensors" are damaged, shop will know engine was overheated. The owner didn't tell me about the sensors, I just noticed them when reinstalling the engine. Engine has a one year, unlimited mileage warranty. Void if engine is operated when low on oil, or overheated ... common sense! He recommended oil be changed after the first 500 miles, every 3,000 miles "max" thereafter, for long engine life.

 

When doing any motor work where the pump is removed, stand it on it's nose and add anti-freeze to keep the seal wet. Even a low mileage good tight bearing pump will leak if let dry. Time for new pump.
.....=o&o>.....

 

Bought the new pump from NAPA, only $35. No leaks to report...yet anyway. Thanks all.