Originally Posted by bestfriend
1.- What do I need to do to "clean up the end caps"?
2.- Are there other things I should do while I have it apart?
And for the dumb question:
3.- Is the fresh water system going to drain when I open the heat exchanger?
1. To clean the end caps, remove them (large bolt in the center) and use a wire brush, rag in solvent, or whatever you like to remove the scale, corrosion, etc. Depending on how bad they are you may want to paint them before re-installing.
2. With the end caps off, you may want to clean the heat exchanger as well. You can rinse water through it, push a rag through, whatever.
If you have time, check the condition of the gaskets, and order new ones if they are worn. If you don't have time buy replacements ahead of time.
3. The coolant (it should not be fresh water but standard automotive type coolant) will not drain because the raw water and coolant to not mix - it is a closed system. Seater will drain when you remove the zinc or end caps, but no coolant.
If you don't know when other maintenance was done you could also change the coolant, fuel filter(s), oil and filter, and transmission fluid.
For the coolant there is a drain on one side of the engine (same side as the throttle) that you connect a hose to so you can safely dispose of the old coolant). Open the bleed valve on the top of the engine and add new coolant.
I use a vacuum pump to change the engine oil and transmission fluid. Piece of cake and now you know are set for some time.