How to drain coolant?

[DrNate 426]

Any tips, advice, or pictures about how to drain the coolant out of PCM 409?  Mines a 2011 and the Owner's Manual is woefully inadequate

[InfinitySurf 302]

I can tell you one thing, one of the drain plugs in the manifold has coolant in it. When I was winterizing....I pulled the raw water drain plug and drained, then saw the 2nd one and was not sure so I pulled it....had to jamb it back in real quick cause it had the closed coolant in it. Luckily I did not lose much, prob 1/3 quart. I am curious too the details on how to do full coolant flush since I was thinking of replacing my DEXCOOL this Spring too. Don't remember exactly but think the manual calls for every 5yrs.

[RhuntIII 555]

Yes it was saying 5 years in the owner's manual. Also it's saying to check your PH level in the coolant. 

[DrNate 426]

yeah, every 5 years on the DEXCOOL.  I have read bad things about it on GM forums, especially if it starts to run low, which I think mine has

Edited February 18, 2018 by DrNate

[DrNate 426]

8 hours ago, InfinitySurf said:

I can tell you one thing, one of the drain plugs in the manifold has coolant in it. When I was winterizing....I pulled the raw water drain plug and drained, then saw the 2nd one and was not sure so I pulled it....had to jamb it back in real quick cause it had the closed coolant in it. Luckily I did not lose much, prob 1/3 quart. I am curious too the details on how to do full coolant flush since I was thinking of replacing my DEXCOOL this Spring too. Don't remember exactly but think the manual calls for every 5yrs.

Where was this "second one" in relation to the raw water drain plug?!?!

[h20king 794]

Start draining at the block and work your way up. Block is full of antifreeze  as well as the manifold jackets. 

[InfinitySurf 302]

4 hours ago, DrNate said:

Where was this "second one" in relation to the raw water drain plug?!?!

Facing the engine from the back seat: The raw water drain was on right side.....coolant drain plug was left of center at bottom of the heat exchanger (sorry, I said the manifold before and was wrong)

[DrNate 426]

I definitely know where you are talking about on the heat exchanger.  I wonder how much of the coolant I could get out just removing that one plug?  Any guesses?  Mine is 6 years old and I need to change it

[h20king 794]

You need to pull the block drains as well as blow out the heater to remove all the coolant. 

[DrNate 426]

11 minutes ago, h20king said:

You need to pull the block drains as well as blow out the heater to remove all the coolant. 

I don't have a heater.  Or did you mean the heat exchanger?

[h20king 794]

No was referring to in boat heat. Drain the block and heat exchanger then refill. 

[DrNate 426]

Stupid question, but does that mean that I have a second water pump for the freshwater part and one for the coolant part?

[h20king 794]

Yes in sorts. The water pump bolted to the front of the engine circulates coolant in the engine. Your fresh water pump circulates water through the v drive oil and trans coolers the heat exchanger then out the exhaust. The water pump bolted to the front of the engine on fresh water cooled boats just helps circulates water through the system. 

Edited February 19, 2018 by h20king