This was the first time I have ever worked on my own truck. I'm attempting to learn mechanical and electrical systems to do basic maintenence on my own truck. Today I attempted to flush my coolant.

Found some good information online, here, YouTube, etc. I even took off the reservoir and cleaned it all out. Emptied, flushed, ran for 15 minutes, rinsed, filled with water, ran to temp and emptied, started filling with coolant, and then PROBLEM:

-After letting it empty thoroughly for about 20 minutes, it would only take a half gallon of coolant.

So I let it get hot and dangerously released some pressure forcing air through the reservoir and could get it to take full gallon but that was it.

Capacity is almost 3 gallons...

What am I doing incorrectly? Thanks.

 

Put the front passenger tire up on a ramp to elevate the truck then fill the rad as full as you can. Leave the cap off and start the truck this won't hurt anything I promise. Your coolant will disappear and just make sure you have more on hand and keep filling. This allows the coolant to fill the entire system and having the truck elevated will help force the air out of the highest part off the system. Make sure you let it run long enough to let the tstat open and fill the other side of the system as well. Once its full and not taking any more coolant just let it run for awhile loner to force out any more air that may be in there. Then put your cap on and make sure you have coolant in the res tank.