Coolant

[James Kenyon]

Can anyone advise how to vent the cooling system to drain and replace the coolant in my 2002 GMC Envoy? My Envoy manual says to remove the heater hose, but the hose is not accesible without removing more parts that I'd like to try to remove. I have a Haynes manual that says to remove the "coolant air bleed hose" from the throttle body, but I cannot find any such hose on my Envoy. Any suggestions?

[Zembonez]

Can anyone advise how to vent the cooling system to drain and replace the coolant in my 2002 GMC Envoy? My Envoy manual says to remove the heater hose, but the hose is not accesible without removing more parts that I'd like to try to remove. I have a Haynes manual that says to remove the "coolant air bleed hose" from the throttle body, but I cannot find any such hose on my Envoy. Any suggestions?

I typically remove a lower radiator hose to drain coolant. I'm not sure how you need to "burp" the system on that vehicle when refilling but most modern coolant setups require it. I'm sure somebody with Envoy / Trailblazer experience will chime in here.

 

Welcome to the ZOO!

[bigredmariner]

Welcome to the forum.

[pennzoil29]

Welcome aboard

[REV353]

I agree, pull the lower hose and the Rad cap. Fill the tank and start the truck, the system will bleed it's self through what I call the puke tank. You will need to re check after you drive it a bit.

[James Kenyon]

I agree, pull the lower hose and the Rad cap. Fill the tank and start the truck, the system will bleed it's self through what I call the puke tank. You will need to re check after you drive it a bit.

Thanks. I pulled the lower radiator hose and the radiator cap as suggested, but only 6 qts. of the 13.9 qts. capacity would drain. Seems that I do need to vent the block to allow the coolant to drain. Any other suggestions?