heat exchanger internal leak?

[cfelton]

I ran my 85 mcm170 mercruiser about 2 weeks ago, everything was fine. I drained the raw water out of the heat exchanger so it would'nt freeze. I went out thursday and took an end cap off the heat exchanger to make sure it was all out before this next freeze and about 6 oz. of antifreeze ran out the sea water chamber of the heat exchanger. I replaced the riser/tank and gasket last year. Looks like I've got a very small leak in between my coolant chamber and the sea water chamber in the heat exchanger. What do you all think? My thinking is, if it was the riser was leaking it would fill up the exhaust manifold and run out the exhaust before running back into the heat exchanger. This is not happening. Am I right to think I need a heat exchanger? If so does anybody have a good 4in. heat exchanger, reasonably priced!

 

[Don S]

Re: heat exchanger internal leak?

It's possible the heat exchanger is bad. Just take it off ane pressure check it to find out. I usually just pull the HE, drain everything out of it. Plug one AF outlet, rig the other AF outlet for a pressure tester, pull the end caps stick it in a tub of water and pressurize it. Bubbles will tell the story.

 

[cfelton]

Re: heat exchanger internal leak?

I pressurized the antifreeze chamber and found a pin hole on the plate that goes across the end of the tubes.It looks like I might be able to braze the hole up, its between the tubes and the outer shell. I'll give it a try before I buy one. Thanks

 

[Rocky_Road]

Re: heat exchanger internal leak?

I pressurized the antifreeze chamber and found a pin hole on the plate that goes across the end of the tubes.It looks like I might be able to braze the hole up, its between the tubes and the outer shell. I'll give it a try before I buy one. Thanks

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