Westerbeke 12B Two Coolant Flush/Replacement - SailNet Community
LinkBack Thread Tools
post #1 of 4 Old 04-30-2013 Thread Starter
Junior Member
Join Date: Sep 2012
Location: Ontario, Canada
Posts: 12
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
Westerbeke 12B Two Coolant Flush/Replacement


I was wondering if anyone had any pointers for replacing the coolant in my Westerbeke 12B Two.

I currently have the old green coolant that is starting to look not so fresh. I don't have any history behind when it was last replaced. I'd like to go to a long life coolant but I don't know exactly how to go about that. The manual is lacking as to where the drain plugs are to eliminate the old coolant.

I should mention that I also have a water heater so the coolant does circulate through it.

Any pointers would be greatly appreciated.


thron is offline  
Quote Quick Reply Share with Facebook
Sponsored Links
post #2 of 4 Old 05-08-2013
Junior Member
Join Date: Sep 2012
Posts: 2
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
Re: Westerbeke 12B Two Coolant Flush/Replacement

I also have a Westerbeke 12B-Two and am about to do a flush for the first time... I would love to hear some pointers from anyone with experience with this engine.

W, Since it sounds like you may be a bit newer to this engine than me you might like to know that it is actually a "marinized" version of a Mitsubishi K2AS Diesel Tractor engine. If you look up the manual for the K2AS you will see that Westerbeke copied some of the pages right out of the original Mitsubishi manual. This is useful knowledge because it can help you find cross-referenced parts for the diesel tractor engine at a fraction of the cost that Westerbeke sells them.

Things like the raw-water heat exchanger, water cooled exhaust, and the extra pulleys to run the raw water pump are the marinized parts that Westerbeke added.

Here's my list of commonly replaced parts with cross-references to commonly available parts. If anyone else has anything to add to this list please share the knowledge!

Engine Oil: 10W30 Marine grade, Diesel Grade, 3.3 quarts

Oil FIlter: Napa Gold 1334 or FRAM - PH3593A or similar cross reference

Westerbeke Water Pump: 46120
Westerbeke Replacement Impeller: 46622 (OEM kit) , Globe 1112 (aftermarket run-dry impeller avail from Defender)
Also found a reference to a "volvo-penta-3586501-R13" fitting the 12B-Two raw water pump

Replacement Alternator: Advance Auto Parts Part No. 186-0486 which is an alternator for a 1983 "Mitsubishi Cordia" Cost $65 compared to $400+ from Westerbeke

Hope this helps!

liquidus is offline  
Quote Quick Reply Share with Facebook
post #3 of 4 Old 08-25-2013
Junior Member
Join Date: Jul 2013
Location: Cranston, RI
Posts: 26
Thanks: 3
Thanked 0 Times in 0 Posts
Rep Power: 0
Westerbeke 12B Two Coolant Flush/Replacement


I have same setup, thanks so much for the info here. Wondering if you Havedetails on gearbox fluid change. I have the manual, but it does not specify if fluid level should be checked with engine running or stopped. Any thoughts on this?
tatracy is offline  
Quote Quick Reply Share with Facebook
post #4 of 4 Old 09-05-2013
Junior Member
Join Date: Sep 2012
Posts: 2
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
Re: Westerbeke 12B Two Coolant Flush/Replacement

Assuming you have the original Hurth transmission you should check the fluid level with the engine off. Don't screw the dipstick back in when checking your fluid level either... Unscrew it, wipe it clean, then reinsert until it stops at the threads but don't screw it down, then pull it back out and look at the level. I always checked mine when the transmission was cool. It is usually suggested to replace your fluid once a year or every 250 hours of use.

If you poke around on the Westerbeke website long enough you should be able to find the technical manual for this engine. It has lots of extra information including info on the transmission.

Incidentally, I ended up replacing the Hurth HBW-10 transmission that was originally on my Westerbeke with a Twin-Disc TMC-40P 2 seasons ago. So far it has worked very well with about 250 hours on it and no problems at all.
liquidus is offline  
Quote Quick Reply Share with Facebook

Quick Reply

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Register Now

In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page

Similar Threads
Thread Thread Starter Forum Replies Last Post
Proper coolant for Westerbeke 30 B three therapy23 Diesel 3 02-01-2012 05:16 PM
Yanmar coolant replacement Norstar Pacific Seacraft 8 11-11-2009 09:47 AM
Flush Seacocks Aleutian Tern Racing 6 12-21-2008 05:35 AM
Westerbeke replacement parts jonlgauthier Gear & Maintenance 2 10-31-2007 09:20 PM
Impeller replacement on westerbeke sailortjk1 Gear & Maintenance 10 07-16-2007 07:44 PM

Posting Rules  
You may post new threads
You may 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 On
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome