Hi all,

First post here so I hope it's in the right place. I've searched but not been able to find an answer to my specific question.

On my engine (V6), the thermostat is on the lower radiator hose. To drain coolant, I understand that the first step is to use the radiator drain. Step two, according to the Haynes manual, is to remove the lower radiator hose to complete the drain. First off, how will anything drain when the thermostat is there and closed? Second, how much coolant will still be in the engine at that point?

Maybe the manual is just giving specifics for the 4-cylinder?

Thanks,
Tyler

 

It'll drain slowly through the little vent hole in the T-stat. Or remove the "hose" by opening the T-stat housing rather than peeling the rubber hose off.

 

Thanks for your quick reply. A couple follow-ups:

Is the vent hole the little hole that all the videos say to orient to the top when installing a thermostat?

I do intend to remove the thermostat so I can do a complete flush of the system, but I didn't want to pull it out blindly without knowing how much fluid might be behind it.

So will the coolant drain through that vent hole all the way down to the radiator drain, or will I actually have to remove the lower radiator hose to get it to drain from the vent hole?

 

I've never had a Honda V6 so I'm kinda generalizing... Hope someone else chimes in.

I usually pull the T-stat as soon as the radiator is drained. Seems like it makes a mess regardless of waiting longer. But I DO have a pretty big pan to catch it...

Getting it all to drain (as well as releasing air bubbles when filling), I usually have to disconnect the hoses & flex them down, up, around, etc. as needed. It never ALL drains out, because there's 1 or 2 quarts stuck in the engine without any good way to drain. I normally drain/fill several times until the color becomes clear.