I am going to change my thermostat and flush the antifreeze from my truck this weekend. My question is how do I get the coolant that is in the engine out completely?

 

Run a garden hose into the opening the t-stat fits into. Then disconnect the lower radiator hose and run the water until it comes out clear.

Do the same with the radiator and heater hoses going to the heater core(s).

Once all coolant has been flushed out, use compressed air, a vacuum set to blow, or whatever you have that will blow air into the t-stat opening, radiator, and heater hoses in order to force the water out. Once the majority of the water is out, put it all back together, add the correct amount of antifreeze, then top it off with water.

 

Where is the Heater Core(s) located?

 

The front heater core is inside a plenum box behind the dash. The hoses run through the firewall. If you have a rear heater it is inside the drivers side rear of the truck behind the trim panel.

 

It is my understanding that, correct me if I’m wrong, but when refilling the radiator etc after a flush , coolant concentrate and distilled water should only be used??