After a month of not being able to work on the truck due to surgery Im finally able to get back to it. I am going to try to flush the heater core today/tomorrow while we still have mild weather and before it gets nasty starting Friday (I would flush the whole coolant system but I'm still under limited mobility restrictions)

I have been reviewing the procedures on youtube and the shop manual and did have a question regarding how to properly re-bleed the system. from what Im seeing after you refill the coolant system you need to open the radiator cap on the passenger side top of the radiator, stick a funnel in it, and run it and I guess the air bubbles just come out through the funnel? Or is there another proper way? Also is the proper procedure to refill to pour coolant in the radiator or diectly or just in the overflow?

Thanks!

 

Park or jack vehicle on a slight incline with the radiator cap uphill.
Drain your coolant system at the radiator.
Drain the overflow tank by disconnecting the small hose at the radiator cap & lowering it, then open the overflow cap.
Disconnect the heater core hoses; note original hose orientation; let that drain.
This is a good time to install a new RadiatorCap+ThermoStat & replace any old coolant hoses+clamps.
Reconnect the heater core hoses, reversed from their previous orientation.
Flush per those kit instructions & again drain the coolant system & overflow tank.
Reconnect the overflow tank~radiator hose.
Fill the system with 50/50 coolant at the radiator cap.
Fill the overflow tank to the mark, roughly half full.
Idle the engine with radiator cap off & heater on, 5~10min to warmup; confirm thermostat is working.
shut it off, check for leaks.
Top off the radiator, install the radiator cap.
Drive vehicle for 10min with heater on, noting temp gage, then let it cool off for 2hrs.
Check for leaks, top off radiator & check overflow tank level.
Drive, cool off, leak check, top off, one more time, then drive normally.

 

You can flush just the heater core using a garden hose by removing both heater hoses at the fire wall, mark which hose is on which side, because you will be REVERSING THEM when you hook them back up, heater cores do not have an assigned IN and OUT, so you SHOULD reverse them every 2 years to back flush then while driving, it will help them last longer

To refill any cooling system remove, or in your case just leave, one heater hose and refill via rad cap opening, when coolant start to come out of the hose reattach it to the heater core, all the air is out of the engine
The thermostat is closed when engine is cold so the air inside the engine can't get out when refilling, the heater hoses are on the engine side of the thermostat, so air CAN GET OUT of the heater hoses when refilling