Heat Exchanger Flush Instructions - Kohler 5e

Suma

New Member
Feb 10, 2011
12
Sydney, Australia
Boat Info
2004 Searay Sundancer 320
Engines
6.2L Mercruisers & V Drives
Can any suggest the process to flush out the heat exchanger or direct me to a video? I’ve searched and can’t find any info.

I’d also like to check the raw water line for any impeller bits. Is that an easy process?

I’m having some issue with my genset a 2006 model. I purchased the 320DA 18 months ago and it was suggested that I should do this to ensure all is clear.
 
Suma - You need to back flush it when you do it. Remove the hoses from the raw water intake and output and attach auxiliary hoses to each of these. You can back flush using a water hose or a cleaner such as barnacle buster. Either way have the exit hose go into a 5 gal bucket so you can see if any pieces come out. I do a loop when I do mine using barnacle buster and a drill pump. Fill the bucket with proper diluted barnacle buster and using the drill pump circulate it through the exchanger and back into the bucket. Do this for 15 - 20 min. You will need to replace your zinc rod if you use barnacle buster as it will most likely be destroyed. Should change it anyway if you haven't.
 
Thanks Korkie. Do I need to shut off the raw water seacock before disconnecting hoses?
 
Yes if you are in the water. If not, no as it will be disconnected at both ends. I have a lock on button on my drill. I have also used one without a lock on button by using a wire tie, keeping a set on snips close by. You do not have to run it wide open speed. Just need to keep the fluid moving as it is the fluid that does the work, not necessarily the pressure.
 
Ok, I have one of these pumps I have used to push antifreeze thru the thru hull for the AC winterization. Never thought about using it to flush.
 

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