Water pump question

blue66tang

Founding Member
Jan 20, 2001
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Medford, OR
I am working on a 89 5.0 water pump. I just put the engine in a jeep and went to fill it up with water and it started running out from somwhere around the pump. I cant figure out where its from. Its not coming out the water pump weep hole i dont think. Is there a comon place that these things leak water. My pump also had some plate on it. Is this nessasary? If i took it off would it be ok, My 66 mustang doenst have that plate. Im hoping its not comeing from the timeing cover somewhere.
 
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There are 2 gaskets behind the w/p. On my 5.0 the gasket between the timing chain cover and the block was leaking. The plate is required since it is the back of the w/p. You may be able to remove it but I would imagine you would run into coolant circulation problems. Ford put it in there for a reason.
 
Without that plate it's not going to pump right so leave it there. There is a gasket however between the plate and the pump that needs to be good, and between the pump and the timing cover that needs to be good, and the timing cover gasket needs to be good. Make sure you're not missing a bolt somewhere or have one of the wrong length in the wrong position. Other than that, you have the upper and lower hoses, the bypass hose and the heater hose. If the bypass hose is leaking from the underside of where it connects to the water pump it can be hard to identify.

Really what I recommend is get yourself a pressure tester and pump up your cooling system and it'll start hissing and bubbling from where the leak is. :nice:
 
That backing plate is actually exposed along the back of the WP in a spot. It it is missing, the whole circulation system is not sealed. And if you don't put sealant in between the backing plate and pump, you will have many leaks. As for the mount to the timing cover, you only need to seal around the water inlet and outlet, not the parts that go from side to side. The timing cover is not designed to be exposed to water except at the inlet & outlet.

Good luck on the pump R&R.
 
Yes, those are the bolts for the exposed edge of the pump. If they are missing, the backing plate is most likely not sealing against the pump in that spot. You might get lucky and be able to squirt some silicon sealant into the gap, and then tighten up the two bolts. Worst case, remove the pump and reseal the backing plate with the bolts in place before installing the pump on the timing cover.