# 1966 gto 389 water pump internal housing



## tonyli (Aug 14, 2013)

Hi, I am running a little hot in traffic and days with ambient temperature over
85 degrees. It is pretty much stock 389 with a mild cam a recent rebuild before i bought it last year. Car runs great with exception of this issue. Factory a/c car with a 4 row Harrison radiator. I run at 190 all day if cruising once I get into traffic it creeps up to about 220 or 230. 

I went to replace the water and notice two plates inside the water pump housing. The internal housing has a spout, but this spout is corroded and not completing the connection where the lower radiator hose is in the pump.

Are these two plates a necessity? I am thinking this corroded plate reduced the flow rate at idle speeds not allowing the antifreeze to go threw the radiator causing me to run hot. I will find out tomorrow, but what do you guys think?

Thanks In advance for any responces.


----------



## the65gto (Oct 9, 2008)

Read the upper "sticky" causes for gto's overheating ... and it will tell you everything you want to know. Yes those plates are necessary as is the spacing between these plates and the vanes on your WP impeller. Its a long read but worth while. IMHO Some pics would be great.


----------



## tonyli (Aug 14, 2013)

Thanks checked out the sticky. Got the inner plate and divider plate made the necessary adjustments. Also I have an after market flex fan with the wrong spacer ( it was too far into the shroud) so I replaced spacer
so the fan is a half closer to motor. Replaced the radiator cap put fresh antifreeze with distilled water. cruised it today the temperature was between 190 and 205. with the a/c on 215 to 219. So far its good. Thanks Again


----------

