A high pressure will be able to push the coolants into the heater cores.
If it has rear heat it has two heater cores. One in the front and one in the back.
one
I have bought a car 2 years ago and want to add a heater core, I found many online sites which sell heater cores but the best is http://www.autopartswarehouse.com is a very good site to buy heater cores from.
The 2003 Chevrolet Trailblazers has two heater cores. One operates the front area of the vehicle while the other heats the rear of the vehicle.
replace front heater corefront and rear have independent heater cores
There are 2 if it is dual climate control
Heater cores in all vehicles are up under the dashboard inside the vehicle.
To replace most heater cores you have to remove the dash on the passenger side.
pressure
It has 1 in under the dash. passenger side.
Cost about 1000 - 1200$. This is one of the hardest heater cores to replace.
In the 1993 Pontiac Transport Van, the two heater cores are interchangeable. To install one heater core in another position, longer hoses might be necessary to reach the necessary hose positions and new holes might need to be drilled.