OK gonna flush the heater core today to try to get some heat. what direction should I flush it? Does it matter? Also thinking about running some CLR through it. Anyone done this before got any tips?
Thanks

 

CLR does horrible things to aluminum...... don't really recommend that. Just give it a try with straight water first.

coolant (heatant?) flows from the hose at the intake manifold, thru the core, and then back into the water pump via the hose to the steel pipe that plugs in to it by the power steering pump. Flush in the REVERSE direction first, and then the other way. Go both directions a couple times, ending in the reverse direction. Then, put the hoses back on, trying to lose as little coolant as possible. Run the engine, burp the system, and see how it feels.

 

what do you mean burp the system? I know to get air out but how do I do it

 

Park at as severe and angle as you can find, (without worrying about your truck rolling over down the hilll......) that elevates the passenger front corner of the truck, just let it run with the radiator cap off for a little while, until the thermostat cycles at least twice. Top off the coolant, put the cap back on, drive it away.

Never Never Never take the radiator cap off when the coolant is hot, and the system is under pressure. You will get a very rude surprise, and a complimentary trip to the ER.

 

Didn't know I could run it with the cap off. you sure?

 

Yep. I drove mine with the cap loose to the hill I wanted to use. (less than three miles)

 

It's just fine to run with the cap off unless you're heavily loading the engine.