Heat Exchanger Weeping (Me Too)

[upthesolent]

Cleaned HEx out, fitted new O rings, carefully tightened end caps so they are not askew.
Tried Lithium Hi Melting point grease first time, then impeller lubricant 2nd time, but I still have dripping from the cap fitting, more so when engine heats up.

The tapered flanges of the engine where the end caps are seated do have very slight pitting due to corrosion over the years, but I would have thought the O rings would allow for that.

I feel like using some product (like loctite) to use as a sealant, but next year when I go to clean the exchanger I am going to have even more massive problems getting the end caps off.

Pretty desperate here. Got just over an hour of water to try reseating the end caps again, or tomorrows's high tide.

Help Me!

 

[Martin_J]

You didn't mention which engine.. or I missed that part..

How old are the caps.. perhaps the rubber they are made from is slightly less flexible than if they were new....

My caps on an MD2040D are just fitted clean/dry.

 

[Martin_J]

Second thoughts.. This I assume is a leak from the outer (rather than the inner) circuit.. Could there be a blockage somewhere after the heat exchanger that is causing increased pressure..

 

[daveyw]

I replaced the o-rings on my nanni 20hp and suspected the new rings were smaller than the original. In the end I made up new rings from a kit.

 

[david_bagshaw]

I would suspect rings of too smaller a diameter, use 5mm if 4mm etc, as the seal between the tube stack and casing should be easy to seal , and the end caps not touch the header tank,. double check the centre bolt, if not the ring clamp type.

we had through bolt type x3 for over 20 years and crescent clamp type x 2 for for another 20 years so far, always used lithium type grease liberally applied, with care the stack is in the middle.