My truck is building pressure somewhere and causing a little coolant overflow from the reservoir and keeps making the water pump seals fail... Completely stock.. any ideas??? Thanks!

 

has the rad cap been tested or replaced? the cap should protect the system when the tstat is open.

 

Yes, thermostat and radiator were replaced. I had to replace them on my own dime as they were tested and found to be OK....

 

you arent hammering the pedal with a cold motor are you? when the tstat is closed and alot of rpm and cylinder temp is generated, there is over 60psi of pressure developed in the water jackets. those of us lucky enough with early common rails just blow a freeze plug. i wonder if that is your issue.

 

Negative! LOLOL I always just coast it along until it gets to running temp... Dealer is not being of much help anymore. I keep getting a little drizzle of coolant out the top of the overflow and twice now I have got a little coolant out the water pump area immediatly after shut down. Only a cap full or so then quits and dries quickly... Any ideas?