Extracting old coolant from expansion tank

[srah1953]

Hi All
How do you get old coolant out of the expansion tank? I could, I imagine, rig up a pump and suck it out of the top of the expansion tank but I'm wondering is there a trick to this. The Yanmar manual says not to mix different types of coolant as it could create sludge.
Many thanks

 

[Stork_III]

Doesn't the expansion tank coolant flow into engine under gravity? Draining engine will drain ET. Or take off pipe.

 

[srah1953]

Doesn't the expansion tank coolant flow into engine under gravity? Draining engine will drain ET. Or take off pipe.

I thought that's what would happen, but no. The pipe from the expansion tank is at the top so taking it off won't help.

 

[alan17]

You could syphon the fluid from the ET or pump it out with a Pela type pump but on my Yanmar new about 6 years ago the supplied ET is bulkhead mounted and can be lifted off its bracket and inverted.

 

[srah1953]

You could syphon the fluid from the ET or pump it out with a Pela type pump but on my Yanmar new about 6 years ago the supplied ET is bulkhead mounted and can be lifted off its bracket and inverted.

Thank you very much. That's just genius. I never would have guessed.

 

[sailorman]

Thank you very much. That's just genius. I never would have guessed.

 

[srah1953]

I think that would look good from any angle
PS There's a small vent hole in the top of the expansion tank. No diagrams this time!

 

[sailorman]

I think that would look good from any angle
PS There's a small vent hole in the top of the expansion tank. No diagrams this time!

the tank is sealed with a pressure cap of possibly 13 psi