rubber heat exchanger seals on a NL 12kW

Thanks to those that gave input assisting in my first seawater pump replacement.
Change was simple in the end. However there's reduced flow out the wet exhaust so the to check the heat exchanger for impeller vanes pieces.....

1) after hose clamps removed, the rubber seal came off the housing lip with moderate effort, but haven't been able to work if off the narrower segment on the exchanger element. Any tricks besides force? Hoping not to damage the rubber seal.
2) On the exhaust end, did you have to remove the rubber seal from the elbow to get it off the exchanger?

Thanks in advance.

Sandy

Put new boots on each end, they are not that expensive and are critical in separating coolant and sea water. Cut them off if needed to get it apart. Clean tube bundle sealing surfaces to clean metal for new boot install.

Sandy,

There are a few tricks in the linked article, if you were not aware. Please note the recommended order of installation with the new boots, tighten the small side before the big side.

Safe Harbour | Northern Lights Cooling System Maintenance – Slowboat

Thanks Jeff.

I couldn’t (yet) work the hose off the exchanger tube on the front end.

Will try agin this weekend.

Good luck.

I think I am going to get into my generator this weekend. New mixing elbow, clean the heat exchanger if needed, new coolant, adjust the valves, new fuel filters, new oil and oil filter. I am not looking forward to the mixing elbow job, as there appears to be some sealant between the hose and nipple.

Suggestions welcomed!

So, just elbow grease got the two caps off.

What are your recommendations to clean the bundle? Clean the face on inflow side?
Fresh water only, barnacle buster? dilute muriatic?

Saw a recommendation for CLR, but CLR labelling says do not use on copper.

Have copper rods ordered to clean the tubes, although none are visually blocked.

I will soak my bundle in Barnacle Buster (at their recommended concentration) if it is needed.

Last time, I had no indication that soaking was necessary, so I didn’t soak. It was also the first time I performed the service since we purchased the boat, and I didn’t have any records indicating it was done previously.

Sounds like you are making great progress. I can’t say I am.