Probably the wrong gasket. I had the same problem recently with a reverse rotation pump on an older style timing cover. The shape of the gasket around the driver side port is different.

Pull the pump. Make sure the gasket fits all the sealing surfaces on the timing cover. Then make sure it fits all the sealing surfaces on the pump. There sre two different gaskets with one area that is slightly different.
Also, remove the steel cover from the back of the pump and install a new gasket on there. ALL water pump gaskets should have a paper thin layer of RTV sealant applied, NO MORE than that!

Is the leak between the WP and timning cover, or timing cover and engine block?
Either way, I suggest checking for cracks in the timing cover, water pump and block.
If a crack is found, JB Weld may fix it.

You typically don't need the water pump to spin faster than crank speed.  Normally guys under drive the water pump to gain power or avoid cavitation at high RPM. 

However, if the system is not restricted (good radiator cap, t-stat opens, lower hose not collapsing, bypass not blocked, etc.) it shouldn't get over pressure enough to blow a seal.
 

Stock 92 Mustang setup (reverse rotation pump).
(My setup in a 65)

Last edited by Nos681 (3/30/2022 2:09 PM)

Plate to back of Waterpump leaking......
My fix.......take the gasket and roll it VERY tightly in a cylinderical shape...then fold it over its self.
Then place the gasket in your right hand and......see just how far you can throw it!!!
Clean both sides of mating surfaces with lacquer thinner or Brakleen (I love that stuff!). Then apply a generous bead of blue or red RTV all around the mating surfaces. Bolt them together and wait 12 hours or so before exposing the pump to any liquid.
IF that don't do it........check for cracked pump housing.
6sally6

RIGHT







WRONG

Last edited by MS (3/30/2022 7:20 PM)

From your picture, it appears that gasket is not being sufficiently compressed and does not appear to have any sealer on it. The sealer part is not as important as the compression of the gasket in my opinion.
Use a straightedge to check the pump. Since you have tried multiple pumps, that is probably not the issue.


I am thinking the water pump bolts are too long and, when you tighten them down, they are bottoming in the holes in the block before they actually clamp the pump to the timing cover and block.

Cut 1/8” off the bolts and I bet your problem will go away, with a new gasket and paper thin layer of RTV applied to both sides of both gaskets.

Hi everybody,

Today i checked all bolts and spacers that hold the wp in place and it turned out that 1 spacer (just under the blow-out place) was 7 mm shorter then the upper one and two bolts were longer by 3 mm. This causes the Alt bracket to be in an angle and migth have caused a weak place where after continuous high pressure the seal is forced out.

The bracket turned out to be March ones and i could find the original lenghts of the bolts and spacers.  Now i have them all in the correct length and wait for the new wp and seals to re-install them. Fingers crossed!

Thanks all

Mustsed

That is a new one!

Well…Like Rosanne Rosanadana used to say…