What do you call the "Radiator Cap" on a marine diesel?

Jan 7, 2011
5,436
Oday 322 East Chicago, IN
I have a Yanmar 2GM20F engine in my O'Day 322, and the cap on the cooling tank (anti-freeze) needs to be replaced. I don't see a radiator cap listed on the parts list for this engine....do they call it something different (I realize there is no air-cooled "radiator" on this engine....

Or çan I use any old radiator cap from the auto parts store?

Greg
 
Oct 2, 2006
1,517
Jboat J24 commack
Its the same function as A radiator cap BUT for example mine is 7 PSI and matches up with old GMs

In marine it would be called as heat exchanger cap :)
 
Jan 22, 2008
551
NorSea 27 Az., Doing the To-Do list
From my 2GM20F parts manual.....

Published 2010/11 (Nov.)
Figure 26. COOLING FRESH WATER COOLER

REF. LEV. PARTS NO. DESCRIPTION
8 2 128397-44600 FILLER W/BALL

BUT, this looks like more than JUST the cap. You should be able to call the dealer and ask. This should give you a start.

Greg
 
Sep 15, 2009
6,243
S2 9.2a Fairhope Al
its either 12 lbs or 13 lbs psi on the.... 2gm20f a cant remember which
 
Jan 22, 2008
597
Oday 35 and Mariner 2+2 Alexandria, VA
If you have the PSI that you need, amazon has them for about 7 bucks each.
 
Jan 7, 2011
5,436
Oday 322 East Chicago, IN
That is pricey for sure and would try one for auto. Nick
yikes... I will have to check and see if I can a match for a tractor or auto...under $10 bucks compared to $70 for a marine cap!

Thanks everyone for the help. I found 1 reference to a "radiator cap" on Yanmar parts list, but then that part was superceded by a new part number with a description of a "Filler, with ball". Not sure if that is the cap, but it seems to be.

I did find this site with a cap listed for $17....
http://acemarinediesel.com/marine-engine-parts/yanmar-marine-parts/yanmar-129107-44590-radiator-cap/

Will take the old cap off and clean it up to see if there is a part number or a pressure setting on it.

Thanks again for the help.

Greg
 
Sep 15, 2009
6,243
S2 9.2a Fairhope Al
take it to an auto shop/ or auto parts store and have it tested there they can tell you what the pressure is on that cap
 
Mar 30, 2013
700
Allied Seawind MK II 32' Oologah Lake, Oklahoma
I just call mine Rufus. It don't matter none though cause he don't come when I call.