Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 18-03-2014, 01:12   #1
Registered User

Join Date: Nov 2012
Posts: 70
Advice freshwater system

I have drained the coolant in the fresh water system our Yanmar 3gm30f. The system has a subtank and coolant also runs through a hot water heater.

Recently I supplied new coolant by filling up to to the minimum level of the subtank and to the mouth of filler port on the heat exchanger, where the hose runs to the subtank.

After the supply of new coolant I ran the engine in idle for about 30 minutes.

When opening the fillercap on the heat exchanger I noticed that the coolant level had decreased whereas the level in the subtank had increased to between minimum and maximum.

I recall that the level in the subtank was at the minimum mark and the level in the heat exchanger up to the mouth of the filler cap before I drained and supplied the system with new coolant.

So I am wondering if something is wrong now
__________________

__________________
carlager is offline   Reply With Quote
Old 18-03-2014, 01:40   #2
Registered User

Join Date: Mar 2013
Posts: 25
Re: Advice freshwater system

Ok after replacing coolant and running the motor the coolant will expand as it heats up to operating temperature, now as it heats up it will push out to the sub tank, trapped air in the cooling system will move to the heat exchanger,
Now the rad cap.. This is a item that is very over looked, depend on age of the cap, It has to maintain 12 to 15 psi pressure in the cooling system,
It opens as the motor cools down and allows coolant to return to the heat exchanger. I am thinking you have check the levels when the motor was still hot,, ok So top up the the exchanger and run up to operating temp again, after allow motor to cool off again recheck fluids,, All should be good. please do a search on the net about rad caps,, lots of info.
__________________

__________________
Harter is offline   Reply With Quote
Old 18-03-2014, 02:30   #3
Registered User

Join Date: Nov 2012
Posts: 70
Re: Advice freshwater system

Thank you for your reply. It makes good sense.

Is it correct that the rad cap is not functioning if coolant does not flow back to the heat exchanger when the engine is cold ?
__________________
carlager is offline   Reply With Quote
Old 18-03-2014, 02:50   #4
Registered User

Join Date: Mar 2013
Posts: 25
Re: Advice freshwater system

That is very possible,, As the coolant cools down it creates a vacuum in the exchange,, That pulls the coolant from the over flow tank, The cap has two seal area and a spring on it, top seal on the cap keeps fluid in the rad, bottom seal allows extra fluid to move to the over flow and return as the motor cools down
Now in your case you would have air in the coolant system after draining, That would be why the exchange level was not full when you check it, But having air in there may cause the fluid to not flow aback from the over flow.
I would top up the exchange and warm up the motor again, Then after the motor has cooled off recheck fluids,
__________________
Harter is offline   Reply With Quote
Old 18-03-2014, 02:58   #5
Registered User

Join Date: Nov 2012
Posts: 70
Re: Advice freshwater system

Thank you again. I will do as you recommend
__________________
carlager is offline   Reply With Quote
Old 18-03-2014, 03:19   #6
Registered User

Join Date: Mar 2013
Posts: 25
Re: Advice freshwater system

It should be ok,, But depends of the age, Like all things.. LOL
I started jogging after work,, holy crapp that hurts,, LOL I am 55 years old
__________________
Harter is offline   Reply With Quote
Old 18-03-2014, 03:45   #7
Registered User

Join Date: Nov 2012
Posts: 70
Re: Advice freshwater system

Maybe you are jogging too hard
__________________
carlager is offline   Reply With Quote
Old 18-03-2014, 05:00   #8
Nearly an old salt
 
goboatingnow's Avatar

Cruisers Forum Supporter

Join Date: Jun 2009
Posts: 13,649
Images: 3
Advice freshwater system

Quote:
Originally Posted by Harter View Post
It should be ok,, But depends of the age, Like all things.. LOL
I started jogging after work,, holy crapp that hurts,, LOL I am 55 years old

I'd reccomend a slow walk to the pub. At your age who are u trying to impress.

Dave
__________________
Check out my new blog on smart boat technology, networking and gadgets for the connected sailor! - http://smartboats.tumblr.com
goboatingnow is offline   Reply With Quote
Old 18-03-2014, 07:20   #9
Registered User

Join Date: Mar 2013
Posts: 25
Re: Advice freshwater system

I would love a walk to the pub,, Problem is I am in Iraq working, No pub,,
__________________
Harter is offline   Reply With Quote
Old 18-03-2014, 11:41   #10
Registered User

Join Date: Nov 2012
Posts: 70
Re: Advice freshwater system

Problem solved.

Coolant was sucked from the subtank to the heat exchanger when the engine was allowed to cool off for a whole night.


Thanx a lot for your help
__________________
carlager is offline   Reply With Quote
Old 18-03-2014, 11:53   #11
Registered User

Join Date: Mar 2013
Posts: 25
Re: Advice freshwater system

Always happy to help,, I am mostly lurking here, Well until I buy my boat, I am very close to being able to to that, But a lot to learn first,, How do you get them to surf???
Just kidding LOL
__________________

__________________
Harter is offline   Reply With Quote
Reply

Tags
water

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Freshwater System Plumbing Anduril Plumbing Systems and Fixtures 50 11-06-2015 20:27
Advice pls: freshwater boat to ocean Canuck_123 General Sailing Forum 2 02-02-2014 09:34
connecting multiple tanks to freshwater system (+) vacendak Plumbing Systems and Fixtures 12 14-01-2009 13:10
2005 Silverton 38 Sport Bridge- 100% freshwater Woodsong Classifieds Archive 8 18-09-2008 08:40
Freshwater pump: how much oomph? Geoff S. Plumbing Systems and Fixtures 13 02-11-2006 20:00



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 14:52.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.