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Cummins coolant change

Posted: March 13th, 2013, 7:50 pm
by AaHubb
I am planning on changing the anti-freeze and impellers in my Cummins 5.9s this spring. Has anyone done this before, have some tips or insights?
thanx ..Aaron

Re: Cummins coolant change

Posted: July 9th, 2013, 6:16 pm
by ScubaPete
Yes I have done it. You don't have to drain any antifreeze to change the impellers. If you have a twin engine, start with the starboard engine so you can see what you're doing. Remove the three bolts that hold the cover on ( I assume you have a Sherwood pump). Your impeller may, or may not have a threaded end. If so, then a short 3/4 x 18 bolt can be screwed in the give you more leverage and pull to slide it out. Be careful not to lose the key that locks the impeller to the shaft. Check the cam plate and the shaft for wear before reassembly. If any of the impeller vanes are missing, find them. They have probably clogged the bottom of your aftercooler or your transmission cooler.

If your want to change the coolant anyway, then there is a drain filling on the underside of the horizontal pipe that is under the heat exchanger. Re fill slowly and bleed out any trapped air so you don't have cooling problems later on.

Re: Cummins coolant change

Posted: July 24th, 2013, 8:46 am
by Makin' Waves
I am doing the same thing this fall (Oct 13). If anyone has done this let me know, otherwise I will post what I find out from doing it.

Thanks...

Re: Cummins coolant change

Posted: July 24th, 2013, 1:44 pm
by waybomb
I know there is a website specifically for marine diesel engines, but heck if I can remember the name of it.
Try googling "marine diesel engine forum".

Re: Cummins coolant change

Posted: July 24th, 2013, 3:57 pm
by CYO Admin
http://boatdiesel.com Member ship is worth every penny.

Re: Cummins coolant change

Posted: October 10th, 2013, 8:56 pm
by AaHubb
Well the deed is done! Because I did not want a bilge full of antifreeze nor room for a large bucket under the engines I had to get creative. I used an old fresh water pump set in the bilge to pump up to a bucket setting on the salon floor. The input side ran through a short length of vinyl tubing to a funnel that I hung under the drain port. With everything in place I just connected the pump to power, removed the drain plug and sat back to watch. All six gallons were pumped into the bucket and not a drop spilled. :approve: