Coolant Flush Question

bikerjosh

Explorer
I looked around the Mitsubishi forum but didn't see an answer. When replacing the coolant it would seem that about 35-40% stays in the block. Do folks usually pull the engine coolant drain plugs to empty the block (if so where are they located-looked in FSM but didn't see them callout), if not do you refill with concentrated (non diluted) adding some water to get to a 50-50 mix, or just use the premixed coolant, knowing that your ratio will be the majority water?
thanks
 

plh

Explorer
I mix my own 50/50 and then add to the radiator. Seams the pre-bought 50/50 is a premium cost for water. Never have drained the block.
 

snowaddict91

Adventurer
Unless you have a reason to drain/flush the block (post HG repair, etc.) just drain the rad. Buy concentrated coolant, mix ~50/50 with distilled water, and fill 'er back up. I check how much I drained then just try and get my mix close by alternating jugs, I typically don't mix in a bucket or anything like some do.
 

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bikerjosh

Explorer
Thanks for the responses. No HG repair just a little OCD about flushing all the old coolant mixture out and starting over. Figure I have between 4-5 quarts in the block of distilled water, guess I'll go the concentrated route and mix accordingly.
thanks
 

nckwltn

Explorer
you could use a shop vac over one of the radiator hoses to create a vacuum in the system... that will probably get a little more out
 

mcskibadee1

Adventurer
I always just change my coolant after driving with distilled water until it is clear. Once it is clear I drain and add the appropriate amount of coolant. It is a bit time consuming but it is nice to know you have all distilled water and good coolant in your engine. I also use water wetter, not sure it even works but have always used it.
 
i have changed block plugs and block heaters while the engine is in the vehicle VERY MESSY and sometimes very hard to access, wouldn't recommend unless their leaking already. best to drain old coolant..... fill once WITHOUT coolant first i like to use distilled water then.... after draining for the second time offset for the difference i like to mix 60% coolant to 40% water to take into consideration some of the left over water in the block. and during the top up a few days later my experience has been there is some air pockets burping themselves out so it will need at least one top up i always add just a little straight coolant.
 
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bikerjosh

Explorer
Thanks

Thanks all, ended up running about 5 gallons of distilled water through the cooling system to get all the old coolant out, drained and then filled w/concentrated coolant, topped off w/distilled water. Ran it and burped with the front end about 6" up in the air to allow all air to get out of the system.
Now on to the supplemental trans cooler and 7" fan for oil/trans coolers. :sombrero:
Josh
 
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