Flush Heater Core? (1 Viewer)

[CaptBeardilocks]

Hey All,

My truck sat for a couple of years with the engine removed before I got to work on it. New motor is in with new radiator etc etc etc. I'm getting ready to fill & bleed every system on the truck. Should I be good to go as far as filling the cooling system with coolant/distilled water, or should I run some tap water through to make sure there's old crappy coolant in the heater core? Does the heater core drain when you drain the coolant?

 

[maxamillion2345]

Hey All,

My truck sat for a couple of years with the engine removed before I got to work on it. New motor is in with new radiator etc etc etc. I'm getting ready to fill & bleed every system on the truck. Should I be good to go as far as filling the cooling system with coolant/distilled water, or should I run some tap water through to make sure there's old crappy coolant in the heater core? Does the heater core drain when you drain the coolant?

Heater core does not drain.

Are you changing coolant types?

Concerned the heater core has crud in it?

Id probably leave it alone unless I needed to get all the coolant out for a change in coolant types or if I thought the coolant was real nasty or I had bad flow through my core.

Its easy enough to flush with a hose though.

 

[CaptBeardilocks]

No clue what coolant was in it or what state it was in. Truck came to me with no motor.

Do you mean flush the heater core separately with a hose? I hadn’t considered that.

 

[maxamillion2345]

Id do it separately if youre going to do it.

 

[cahill]

Yeah, you can flush it with a hose. If it is connected to the vehicle and tubing is all connected etc make sure the heater control valve is turned to hot so that the water will reach the heater core. I would probably disconnect a return line from the heater core incase there is some crud in there to prevent the crud from getting to the rest of the system.

 

[CaptBeardilocks]

Everything is hooked up now as far as plumbing. I was hypothesizing that I would remove the heat valve from the equation as the CC board isn’t installed right at the moment and feed water straight into the intake at the firewall. Then plumb the outtake hose free of the engine bay to the ground.

Unless anyone else has a better idea.

 

[cahill]

Sounds like that would work. to me. You can manually just move the heater valve to open from the engine bay side as well if you don't want to take that out. It may be easier to do it like you said though. Make sure the hose isn't pushing too much pressure when you flush it.