Drain the water from your 2003 Chevy Express 2500 cooling system. Remove the belt from the water pump. Remove the water return hose. Remove the water pump retaining bolts. Reverse the process to install the new water pump.
YOU DON'T!!! I have a 2003 avalanche and I had to replace the water pump you can't replace the seals!!! It's a defect in the 2001 to 2003 avalanche the seals fail.
look in the manual
how do u replace a flywheel in a Chevy zr2 s10 2003 v6
About $150
how to change the serpentine belt on 2003 Chevy express 2500
How do you replace fuel injectors on 2003 Chevy blazer?Read more: How_do_you_replace_fuel_injectors_on_2003_Chevy_blazer
Replace shoes brake 2003 Chevy
aprox 1.5 hours
It has no drain plug on the A/T.
It could be coming from your heater core, may need to repair or replace it.
my 2003 express 4.3 v6 takes 30gallons
do you need to remove dashboard in 2003 chevy impala to replace heater core