Overheat adventure on 1985 Universal M12

[odaydokay]

I have one of the Mr. cool replacement heat exchangers, copper nickel. The good thing about these is that you can service both ends as they have removable caps at each end. Is it theoretically possible to remove the cap at the far end and run the engine and flush the water into a bucket thus cleaning out any debris that way or is that a crazy idea? (I am thinking that if I don’t get consistently good water out the exhaust next time I go out, I would take a hard look at the heat exchanger and the possibility of debris.)

 

[JoeWhite]

Remove the heat exchanger and clean it. I would think it would be a bog mess the way you are describing. Also your engine will ovetheat.

 

[sailme88]

Remove both end caps and use a .177 cal ( BB/pellet gun cleaning rod) to rod out the tubes. Check the zinc while you are there.. DO NOT apply teflon tape to the zinc threads if it needs replacement.

 

[odaydokay]

Thank you very much. What’s the no-no on the Teflon tape?

 

[Richard19068]

Thank you very much. What’s the no-no on the Teflon tape?

Some think it impedes electrical continuity between the anode and the HX. Others say the threads will cut the tape enough to make electrical contact.

 

[sailme88]

the anode is in place to be sacrificed to stray electric current. It needs a proper ground from its threads to the exchanger. As Richard noted there are differing thoughts..

 

[jssailem]

As you state, “It needs a proper ground from its threads to the exchanger”
The threads provide that electrical link as the exchanger should be connected to the engine, and thus to ground.
Teflon tape is there to reduce the chance of leaking. If there is no leak (and there should not be based on the type of threads used for the zincs and exchanger), then no need for the tape. If there is a leak, check and clean the threads.

Fun Fact: Teflon is used on some electrical wires as electrical insulation. It helps to reduce the smoke should a wire overheat.

 

[dLj]

Thank you very much. What’s the no-no on the Teflon tape?

Irrespective if there are breaks in the threads, it will always have greater electrical isolation between the anode and the threaded hole. You do not want that in this application. @sailme88 is spot on - do not use Teflon tape.

dj