Reply
 
Thread Tools Search this Thread Display Modes
 
Old 10-01-2017, 07:47 PM   #1
Veteran Member
 
City: Baltimore Md
Country: usa
Vessel Name: Graceful
Vessel Model: Marine Trader
Join Date: Jul 2013
Posts: 94
Coolant leak

Just installed a new radiator cap on my engine and now notice coolant leaking from under the cap. Purchased the new cap from American Diesel so I know I got the right one. Any ideas ?
__________________
Advertisement

gonesailing13 is offline   Reply With Quote
Old 10-01-2017, 07:53 PM   #2
Guru
 
BruceK's Avatar
 
Join Date: Oct 2011
Posts: 9,506
What led you to replace the cap? They are very low psi.
The Lehman expansion tank has a meat tube inside it leading to the overflow. If that blocks,and they do(mine needed to be drilled clear),the coolant could look for a place to escape. A low psi cap could be that place.
__________________

__________________
BruceK
Island Gypsy 36 Europa "Doriana"
Sydney Australia
BruceK is offline   Reply With Quote
Old 10-05-2017, 09:28 PM   #3
Guru
 
Bigsfish's Avatar
 
City: Miami River
Country: USA
Vessel Name: Gotcha
Vessel Model: Grand Banks. Heritage. 54
Join Date: Aug 2016
Posts: 2,178
New parts can be defective.
Bigsfish is offline   Reply With Quote
Old 10-06-2017, 07:55 AM   #4
Senior Member
 
Tator's Avatar
 
City: Bainbridge Island/Petersburg Alaska
Country: United States
Vessel Name: Oz
Vessel Model: Bluewater 40' RPH 1979
Join Date: Feb 2015
Posts: 151
Assuming that your engine has the overflow kit, make sure it isn't leaking from the overflow neck insert. Both of mine started leaking after 8 years of being installed. I had to pull the tanks and re-epoxy the neck. I thought it was a bad cap at first.

Tator
Tator is offline   Reply With Quote
Old 10-06-2017, 08:09 AM   #5
Guru
 
Ski in NC's Avatar
 
City: Wilmington, NC
Country: USA
Vessel Name: Louisa
Vessel Model: Custom Built 38
Join Date: Jan 2014
Posts: 5,071
Folks like to step on the caps considering placement. Often the brass gets bent a little and cap will not seal. Epoxy in a new neck and good to go.

And don't step on the cap.
Ski in NC is offline   Reply With Quote
Old 10-13-2017, 10:14 AM   #6
Veteran Member
 
City: Baltimore Md
Country: usa
Vessel Name: Graceful
Vessel Model: Marine Trader
Join Date: Jul 2013
Posts: 94
Did find a leak in the neck but unsure how to remove the old one and what kind of epoxy to use on the new one.
gonesailing13 is offline   Reply With Quote
Old 10-13-2017, 10:34 AM   #7
Guru
 
Bigsfish's Avatar
 
City: Miami River
Country: USA
Vessel Name: Gotcha
Vessel Model: Grand Banks. Heritage. 54
Join Date: Aug 2016
Posts: 2,178
I’m no mechanic like Ski but I have found a small amount of JB Weld or Matinetex works great on sealing small leaks (sometimes big ones too).
Bigsfish is offline   Reply With Quote
Old 10-13-2017, 11:06 AM   #8
Guru
 
kchace's Avatar
 
City: Brookline, NH
Country: USA
Vessel Name: Blue Heaven
Vessel Model: Albin 43 classic double cabin, twin 135 Lehmans
Join Date: Sep 2013
Posts: 1,415
Quote:
Originally Posted by gonesailing13 View Post
Just installed a new radiator cap on my engine and now notice coolant leaking from under the cap. Purchased the new cap from American Diesel so I know I got the right one. Any ideas ?
I replaced my caps and also ended up with leaks on both engines! The problem I had was the aluminum of the tank was corroded between the tank and the filler neck and that corrosion caused the filler neck to bulge inward - preventing the inner part of the cap from being able to seal at the inside bottom of the filler neck.

Installing 2 new filler necks solved the problem and restored correct operation of the expansion bottles.

Ken
kchace is offline   Reply With Quote
Old 10-13-2017, 11:10 AM   #9
Guru
 
kchace's Avatar
 
City: Brookline, NH
Country: USA
Vessel Name: Blue Heaven
Vessel Model: Albin 43 classic double cabin, twin 135 Lehmans
Join Date: Sep 2013
Posts: 1,415
Quote:
Originally Posted by gonesailing13 View Post
Did find a leak in the neck but unsure how to remove the old one and what kind of epoxy to use on the new one.
The filler necks are removed by slicing them inside using a hacksaw blade then grabbing with channellocks and twisting/pulling them out.

Clean up the inside bore, making sure the new one fits correctly, then use JB Weld to glue into place.

After that is done, you run a long drill bit in through the expansion hose fitting from the outside to make a hole all the way through. Just be sure to position the filler neck into the tank far enough so that the hole ends up above the inner seat.

Ken
kchace is offline   Reply With Quote
Old 10-13-2017, 11:22 AM   #10
Guru
 
Comodave's Avatar
 
City: Au Gres, MI
Country: US
Vessel Name: Never Say Never
Vessel Model: President 41 DC
Join Date: Jul 2015
Posts: 3,851
Have the same problem on one of my engines. Coolant is always low, but never goes any further down than about an inch below the cap. Other engine stays full. Put a radiator tester on it yesterday and have a leak at the cap so I will be replacing the filler neck also.
Comodave is offline   Reply With Quote
Old 10-13-2017, 11:54 AM   #11
Guru
 
City: Fairport
Country: United States
Join Date: Jan 2017
Posts: 1,447
After a while the red metal that the cap seals onto can groove or pit. Even without feet involved!
__________________

diver dave is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





All times are GMT -5. The time now is 04:01 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012