GM water pump

[Martin Powlette]

> Carl this thing is begining to make more sense and with your mail it jumped two
> clicks.  I will check your suggestions as soon as I get the new intake gaskets,
> just in case.

Lets add one other thing, what if the engine starts and there is an air pocket in
the pump a dry-start to be precise.  Aren't the seals one ceramic and the other
copper like with a lip seal on the shaft as part of the second ring.  We used
coolant(rust inhibitor,bit of green stuff) instead of ethelyne-glycol antifreeze
so the lubrication quality is not the best. But on the other side of the aguement,
if it is the coolant I have got another vehicle same engine running on that same
coolant with an intake job I did myself.  BTW at what point do you put the 3/8
drive plug on the pump??? after refill to bleed out the air or before installing
the pump to trap the air??Just for thoughts, give me yours Carl.

Martin


>
>
>  Hi Martin,
>       It seems I remember chev's having a bypass underneath the thermostat to
> bypass water back to the water pump while the thermostat is closed and as this
> passage gets old and crusty with rust, block pressure rises with rpm and
> pushes past the seal in the water pump,,,,and yes you are correct there is a
> plate in the intake gasket that is supposed to be in the rear of the
> engine,,,,,an easy way to check for this is to remove the thermostat housing
> and unbend a coat hanger(DIY lol) through the passage to see if the plate is
> in the front by accident....p.s. I have seen many marine engines at over 30lbs
> block pressure and not push past the water pump seal....but over 50 it is
> inevitable....keep in mind block pressure does not necessarily mean radiator
> pressure.....and if checking block pressure you have to check both sides of
> the block as it does not equalize until it joins at the thermostat....hth's
> -Carl Summers