I have a QSB 5.9 2011 w/220 hrs and thinking about changing to coolant and belts. Not the most "threaded" topic on the 'net.
Any help would be appreciated.
That's pretty general so a general answer.
Use a good quality DIESEL rated LOW SILICATE antifreeze. Do not just buy any car rated AF. Ue DISTILLED water to mix it with, not tap water.
If you really want to do it right then get ahold of the minimum specs from Cummins and follow those. However, that will include the above.
There are lots of good suitable AF available.
As for the belt you have the serpentine belt, yes? you will need a breaker bar with a 1/2" square adapter to release the tensioner to remove the belt and then again to reinstall.
I STRONGLY suggest that you look up Seaboard Marine, Tony Athens' site, and read his tips and all the other Cummins 6BT related articles. There is a wealth of info there that will save you a lot of time and money. Or cost you if you don't look after the engine.
Boatdiesel.com is also worthwhile for lots of other info. Just peruse as a guest for a while although to read back more than a week or get into the pdf files you will need to join for $25. Worthwhile also.
I think coolant change is a 600-hour (or X? years) maintenance item, for ours.
Cummins/Fleetguard offers a product called Restore that they recommend for flushing our freshwater (antifreeze) coolant systems, and I presume they recommend that for QSBs too.
Drain the old antifreeze, add Restore and bring temps up, drain the Restore, add fresh water and bring the temps up, drain that, add new coolant at the right dilution, burp the system, etc., done
Look in the manual. There is probably a coolant filter/ additive canister to change and additive test strips to use.
Yes on using a breaker bar to relieve the tension on the belt. A simple job but again look at the manual because figuring out how to run the belt once it is off is sometimes not obvious.
Hint... take a picture with your phone before removing the belt. I have one in case the belt ever breaks so I spend less time staring at the pulleys thinking how I wished I had a picture.
IMHO 200 hours on a 2011 is pretty early for a belt and/or coolant change. W/O checking the manual 600 hours seems more reasonable. But the comfort factor belongs to the captain/chief engineer.