Any 'Stop-Leak' Kind of Chemical for Marine Cooling Systems?

[CSY Man]

Been working on an 80 HP John Deere, or marine Lugger diesel the last few days.

Got all problems solved except a small leak in the cooling system..Pretty hard to reach and impossible to repair properly without pulling the engine.

Any quick fix that will stop the leak and last for a while without clogging up the heat-exchanger...?

(Asking a lot, I know..)

[flashmutt007]

I can't tell you about the heat exchanger, since I don't have a boat yet....

But my Chevy truck (350 V8) had a leak in the radiator a couple weeks ago, good leak too.. lost over a quart a day... A neighbor of my dads gave me a can of RADIATOR STOP-LEAK from Justice Brothers and it did the job! Dry as a whistle...

I, being cautious, just used this as a tempy measure and ordered a new radiator and installed it this past weekend... So I can't tell you how long it would actually last... But for the couple weeks it was in there, it stayed dry.

Radiator Additives

Hope this helped.

[Boracay]

On my John Deere 4045 the cooling system looks to snake it's way round the engine a couple of times.

I'd go over all hose clamps with the right screwdriver/spanner getting them nice and snug. Any that don't feel right I'd replace. If the hoses/tubes don't look good I'd pull them off and have an extra good look, replacing as necessary.

There should be some evidence of a "trickle down effect" if you inspect the engine really carefully with a good light.

The only other place where there could be a leak is the gasket between the heat exchanger and the engine. This is not a huge job to replace.

The fresh water reserve in the heat exchanger does not like to be full. It will push out a bit as the volume expands.

Why do you think there's a leak?

[CSY Man]

Why do you think there's a leak?

Because I see water trickling out and down the port side of the engine...

Been overhauling the cooling system on this engine over the last week, boiled the heat exchanger, replaced hoses and hose clamps, muffler, impeller, gaskets, etc.
Just one little pesky leak left that I am not able to pinpoint.

This engine is under the cabin sole of the boat with a really snug fit and almost impossible to reach down there were the leak it is..Just need to buy some time to get the boat from the yard to its slip 3 miles away.

Hope this helped.

Thanks, will look for the stuff.

[shakey doug]

Most of radiator stop leaks will do the job short term with out any cooler problems they are very hard on hoses causing them to go soft &weak. If you have to use these products to achieve a goal flush system well, if leak is not to bad just put pressure cap on to first notch this will not allow system to pressurize. 3 miles 1/2 hr? In the days of old wet liners it was common practice to use such sealant products after rebuilds etc.

[CSY Man]

3 miles 1/2 hr?

Well, more like 1 hours +..New River, Fort Lauderdale, plenty of S turns and bridges, etc.

Got the stuff and pured in 2 bottles yesteday, let it do it's thing, then the captain and crew took of for the delivery to it's slip on Hendrick's Ilse.

After 10 to 12 minuttes the engine lost power and started smoking.
Supect clogged filters and/or dirty fuel..Had to get Sea Tow.

The leak was plugged however and the engine ran cool, it just would not power up for more than a few minuttes...

[shakey doug]

Another Dear John story by Andy Capp.

[anathema]

I would really advise NOT using an additive leak stopping product in any engine you'd like to keep.

While it will harden a bit and swell around small leaks, it can also do this in the very small tubed water jackets around the cylinders of your engine. Basically you may permanently reduce the ability of your engine to stay cool even if you replace the rad in the future.