Heat Exchanger Help Please

[DrGonzoMIA]

Hi all,

So learning more and more each day about marine engines as some of you will know from other threads.
But I still have newbie questions. All be it I kind of know the answers but want to double check before doing anything daft.
So....heat exchanger. It has 2 systems as far as I know. One to push raw water around the engine and exhaust. And a closed system powered by the standard water pump to cool and also heat calorifier. In my adventures emptying water from everything in order to solve another problem. I'm pretty sure o have drained the closed circuit side.
Now my daft but confirming question is - do I just top that system up like you would a car radiator via the cap on top of heat exchanger? Many thanks.

 

[Mr Googler]

Yes….with coolant

 

[DrGonzoMIA]

Excellent. Thankyou

On another matter as you are my book of wisdom....say I was trying to pull a rubber end cap off the exchanger. But it although the rim appears to be loose (as can get a driver under it). Where it tapers to the smaller / thinner section...it appears to be welded on !? Any ideas. Ta

 

[Mr Googler]

I can’t picture what you’re describing there

 

[DrGonzoMIA]

Basically getting this son of a bitch off...

 

[Mr Googler]

Just pulls off. Twisting can help break the corrosion.

Don’t blame me if it falls apart in your hand ?

 

[westernman]

Yes….with coolant

With rust inhibitor.
If you need to do it often it is a sign that your heat exchanger is going to need replacement soon. And they are expensive.

Ask me how I now.

 

[DrGonzoMIA]

Yeah I'd rather not have to pay 1.5k for a new one ! I've filled it with some decent coolant for now. Going to give the whole engine some love soon. Now I've got it up and running again after some issues. Cheers for advice and info.

 

[oldgit]

Be thankful its not some super complicated labyrinthine thing painted Green and hidden away in the bowels of the engine/ boat.
Heavens above it, looks like to can actually see and get to it.

 

[Bran]

Basically getting this son of a bitch off...

Get a set of hose picks, normally less than a tenner. Makes getting hoses and those end caps off a doddle

 

[PCUK]

Just to clarify. Fresh water circulates around engine block via internal circulating pump, heat exchanger and through calorifier and is topped up through filler cap with anti-freeze. Raw water passes through the tubes in the heat exchanger and exhaust via raw water pump.