Forums » Ask a Question

Use this forum to post your questions to our experts – you need to be logged on to do it (you can register here ), then scroll down to the bottom of this page and click the blue Post Thread words

If you can help answer the question, feel free to post a reply – you need to be logged on to do it (you can register here ), then hit the reply button on the thread.

 

To go back to the experts page click here>>

AuthorMessage
Athabasca
Athabasca

Posted: Wed Jan 05, 2011 2:01pm

Post Subject: How to drain the engine coolant

Tony, We have a narrowboat with a 2 litre Barrus Shires engine, with the coolant running through a skin tank and also through the calorifier. The boat is now 11 years old, and we have owned it for just over 2. Immediatly before the purchase a coolant hose was replaced and the system filled. Since then we have hardly ever had to add any water to the system. However, I realize that the coolant is probably due to be changed. The question is, how do you drain it? Although the skin tank has a top vent, there does not appear to be a drain plug. Do I just undo the lowest hose and attempt to catch as much as I can, then accept that the residue in the tank will just get pumped around the system and diluted? Do you have any helpful tips? Thank you in anticipation, David Fothergill

Tony-B
Tony-B

Posted: Wed Jan 05, 2011 2:40pm

Post Subject: How to drain the engine coolant

First of all make sure the antifreeze you buy is a similar colour to that which is in use. Look in the engine manual to locate the engien block drain tap/plug. Clean all oil and grease from the engine tray and bilge. Remove the lowest hose connection from the skin tank but it might be easier to remove it from the engine end and push the length of hoe into the bilge. Then drain the block via the tap/plug. Remembering antifreeze is deemed a hazardous substance pump/sponge out the bilge into containers and dispose of responsibly. Replace hose and tap/plug & refill at a 50% maximum antifreeze mixture (down to 30% will be fine). Its the corrosion inhibitors that get used up and by using a 50% mixture you allow for some dilution by the coolant remaining in the tank and calorifier circuit and also allow for topping up with ordinary water. Tony Brooks

jeremyfloy
jeremyfloy

Posted: Sat Nov 10, 2012 3:24pm

Post Subject: How to drain the engine coolant

That's really useful. I too have to drain a Barrus Shire engine (1.8L) and would be grateful if you could tell me the volume of coolant I will need to replace. That way I can make sure I have sufficient anti-freeze. Any suggestions?

Tony-B
Tony-B

Posted: Sat Nov 10, 2012 5:39pm

Post Subject: How to drain the engine coolant

The only people who know that are the boat builders and if the boat was built post 1997 the information should be in your boat manual that is mandatory under the RCD. However I know only too well that you would be lucky to find such information there. Unfortunately, unlike a car, no one apart from the builders and yourself has any idea about the capacity of the skin tank, hoses, and calorifier circuits. These vary from boat to boat and layout to layout. The actual engine capacity will be similar across a whole range of engines of similar size but the best is unknown. The best I can suggest is to follow the draining advice I have already given but measure the volume of what comes out of the system. They buy between 30% and 50% of that volume of antifreeze. Tony Brooks

VikingAl
VikingAl

Posted: Tue Nov 20, 2012 8:32am

Post Subject: How to drain the engine coolant

The reply to this seems to answer my question above although I'm not sure whether your suggesting draining the whole skin tank and block or partly drain it and then check the strength? Thanks.

Most Read

Newsletter Sign Up

Canal Boat monthly newsletter
Sign up to receive our regular email newsletter

Our Privacy Policy

Like us on Facebook



Follow us on Twitter

Cache: Disabled for this object  Total Queries: 45.  Total Objects: 164.  Total Unserialized: 5. Total Runtime: 0.24 seconds.