I want to flush out all of that yucky dexcool from my 03 sierra 2500 with a 6.0, before the weather starts getting hot. My question is I couldn't find a drain at the bottom of the radiator like most so do you I guess I have to pull the lower hose. What's up with those gladiator locking clamps those things are a real pain. Does the air naturally find its way out to the reservoir or where to bleed. Which hose going to the heater core is the supply and which one is the return? Any tips from the gurus are gladly accepted.Thanks Ryan

 

Take both heater hoses off and lower radiator hose off the waterpump that drains most of the coolant.

 

Newer NBS's dont have a petcock on the radiator.

The only time i have done it i drained the coolant. Flushed the heater core both ways, flushed the radiator, then ran some flush stuff through it following there instructions on the bottle flushed it all again and refilled with coolant. The flush **** was justice brothers brand it cleaned the system out pretty nice and actually cleaned out the heater core. I was happy didnt have to do a heater core then .

Dustin

 

O.K that sounds good. What about burping the air out?
My wife grew up in ripon and her mom still lives there, Cool little country town.

 

wtf? Did GM get rid of everything that made things simple??

 

Yeah, tell me about it and those gladiator hose clamps bring the suck.