Ducati Sporting Club
Home Calendar Gallery Membership Online Shop DSC Blogs Extras
Go Back   Ducati Sporting Club > Model Specific - Discussion, Technical Problems and Help > STs
Reload this Page Changing Coolant
Forum Home Register FAQ Search Forum Recent Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 09-Dec-2014, 06:02 PM
Phil Butler Phil Butler is offline
Registered Forum User
Bevel Head
Bikes: ST2, 750ss, 350 Forza, W650, CB250RS, 5x Royal Enfields
 
Posts: 85
Join Date: Mar 2002
Mood: Nesun Dorma
Unhappy Changing Coolant

I am getting the ST2 ready for the road after an extended lay up, I have changed the oil and filter plus new belts, so the next task is replacing the coolant, I have drained down and have got to refilling it now. My question is, are these motors prone to airlocking.

I have managed to get 2 litres into the system so far but it does not want to take any more, so I have left it to stand overnight to see if any air will rise to the top and vent through the rad, I have tried with the bike on the side stand and the centre stand, but it seems reluctant to accept any more fluid at the moment.

A secondary question is, when I drained down the coolant was clean and clear, but now I am refilling I can see a film of rust floating on the surface of the new antifreeze and some black floaters (?) a bit like the algae that can be found in central heating tanks. these came to the surface after I had got the new coolant in the rad.

I suppose with hindsight I should have taken the rad off and flushed it out with a hosepipe. But we all have 20/20 hindsight so I plan to run the bike for a week or so then drain down again in the hope that the coolant flow through the motor will get any crap in suspension so that it will drain out. Any ideas on this and the airlocking would be appreciated.

A supplementary query, here in Spain it is virtually impossible to buy neat antifreeze it comes as 30% mixture or 50% mixture, I have bought 50% as specified, but I am wondering if these premixes are made with distilled water (as Ducati specify) or is it likely to be tap water. I tried to get neat antifreeze because I have plenty of distilled water in my workshop but to no avail so the premix will have to do for the time being, until I can get some neat (Puro) antifreeze.
Reply With Quote
  #2  
Old 10-Dec-2014, 08:01 AM
Iconic944ss's Avatar
DSC Member Iconic944ss Iconic944ss is offline
DSC Webteam
Webteam
WSB Hero
Bikes: 1993 - 944ss / Aprilia Falco / ST4S
 
Posts: 7,750
Join Date: Oct 2002
Hello,

I didnt really have any of those issues doing the coolant on my St4s. Have you tried squeezing some of the coolant hoses?

This 'can' disturb some trapped air and help it move along.

I think I used Motul premix myself in the past but Ive also been using WaterWetter without any apparent ill effect.

Hope you get sorted.


Cheers - Frank
Reply With Quote
  #3  
Old 10-Dec-2014, 11:35 AM
antonye's Avatar
DSC Member antonye antonye is offline
Administrator
Webteam
MotoGP God
Bikes: 748S, HM1100S, DD-A
 
Posts: 12,706
Join Date: Feb 2002
Mood: Passion Killer
I always found that squeezing the hoses was a must in the 748 as it is a sealed/pressurised system and can air-lock very easily.


I'd rather die peacefully in my sleep like my Grandfather,
than screaming in terror like his passengers.- Jim Harkins

Ducati 748S | Ducati Hypermotard 1100S | 600-620SS DesmoDue Racebike #111 <-- Sold!! | Avanti Race Parts
Reply With Quote
  #4  
Old 10-Dec-2014, 04:45 PM
Phil Butler Phil Butler is offline
Registered Forum User
Bevel Head
Bikes: ST2, 750ss, 350 Forza, W650, CB250RS, 5x Royal Enfields
 
Posts: 85
Join Date: Mar 2002
Mood: Nesun Dorma
I have tried sweezing the hoses and this did have some effect, but I have only been able to get a fraction over 2 litres into the system, which means I am 1.5 litres short of filling the system.

Today I started the engine and ran it until the thermostat opened, all the hoses are warm, I read that running the bike for 10 mins at 110. deg C then letting it cool should expel the air, if I had 3 litres or thereabouts in the system I would chance it but having just over half the capacity in the cooling system seemed a bit chancy to me.Or is this what you are supposed to do?

I took the rad off today and flushed it out but it was clean and free flowing, the info I have says to drain the coolant with the bike on the side stand, well the drains are on the left so thats what I did, does it matter if the bike is on the side or centre stand when refilling?

The fresh coolant that I drained out today was pretty clean with just a bit of discolouration, so I'm thinking the galleries are pretty clean.

I have painted the rad headers where there was a bit of corrosion so it will go back on tomorrow when its dry, then I'll try refilling again.
thanks for the input lads any other ideas welcome
Cheers
Phil
Reply With Quote
  #5  
Old 10-Dec-2014, 07:37 PM
mc31@york.ac.uk mc31@york.ac.uk is offline
Registered Forum User
Montjuic
 
Posts: 57
Join Date: Aug 2006
I'm presuming you used the correct drain plug on the left hand case?

I had to fit a new radiator a year ago. I drained mine down on the centre stand. As the coolant was perfectly clean and clear, I re-used it.
Although it was a slow process because I strained it through cloth, every drop that came out went back in and to the right level in the header tank.

Squeezing the pipes wasn't necessary either.
Maybe you should try again on the centre stand? I can see how air might get trapped on the right side of the engine if the left is lower because of the use of the side stand.

Failing that, run the engine for a few minutes at a time, checking for hot spots and heat sink between runs. Frankly, I can't see why you'd need to get it to running temperature - just using the water pump to get rid of any air should be regardless of temperature.

If you've got water going passed the water temperature gauge sensor (which is the one on the front cylinder) then you'll get a read out.
If there is no water there, then you won't.
Reply With Quote
  #6  
Old 11-Dec-2014, 06:18 PM
Phil Butler Phil Butler is offline
Registered Forum User
Bevel Head
Bikes: ST2, 750ss, 350 Forza, W650, CB250RS, 5x Royal Enfields
 
Posts: 85
Join Date: Mar 2002
Mood: Nesun Dorma
The workshop manual states that to drain the system it should be on the side stand which I did, the are 2 drain points the larger one on the pump body and a smaller one underneath on the forward cylinder, both of therese were removed and replaced after the system had stopped draining. However it omits to say that the bike should be on the centre stand for refilling otherwise as has previously been pointed out, with the bike leant over the hoses are lower than the highest point of the engine.

The manual also states that when the system is completely full run the engine up to 110 deg C for 10 minutes then let it cool this is to allow any air to be expelled, then top up if needed.

I refitted the rad today and refilled the system and made sure I got as much air out as possible by squeezing all of the hoses in turn as I added enough coolant to brim the rad bit by bit,this seemed to give better results because I managed to get 3 litres into the system just over 2 litres into the Engine/Rad and the rest into the expansion bottle. I ran the engine until the stat opened and let it continue up to 101 deg when the fan cut in. I have now left it to cool down and will check tomorrow if it needs any more coolant in the rad.

I have to agree that squeezing the hoses is a faster way to expel trapped air because running the pump will entrain the air into the water thus making it a much slower process for the air to dissipate, this is based on my experience with heating systems over many years. Air will always migrate to the highest point.....eventually.

Thanks for all the input, I'll know tomorrow if it has been successful this time, in a way the excercise has not been wasted because at least I have satisfied my self that the cooling system is pretty clean now, At 9 for 5 litres it didn't break the bank.
Cheers
Phil
Reply With Quote
  #7  
Old 12-Dec-2014, 10:44 AM
Iconic944ss's Avatar
DSC Member Iconic944ss Iconic944ss is offline
DSC Webteam
Webteam
WSB Hero
Bikes: 1993 - 944ss / Aprilia Falco / ST4S
 
Posts: 7,750
Join Date: Oct 2002
Glad you are getting there Phil, I found some of the hose clips in a pretty bad state and replaced with Stainless, also some of the sensor connectors needed some TLC.

Dont know if you saw the resource links but here is a fun place for research:

http://www.ducatiwiki.net/index.php?title=Main_Page

Cheers - Frank


Cheers - Frank
Reply With Quote
  #8  
Old 13-Dec-2014, 10:29 AM
Phil Butler Phil Butler is offline
Registered Forum User
Bevel Head
Bikes: ST2, 750ss, 350 Forza, W650, CB250RS, 5x Royal Enfields
 
Posts: 85
Join Date: Mar 2002
Mood: Nesun Dorma
Yes Frank I found exactly the same as you, especially the hose clip at the bottom of the rad that was almost rusted through, so I also changed any other clips that were not stainless, at 40 cents a clip its daft not to change them while you can.

All that remains is to book it in for and ITV (mot) and ride it often, bikes deteriorate faster while they are standing than they do when you are clocking up the miles.

Both my Dukes have been idle far too long....running a business will do that sometimes.Thanks for the input its much appreciated
Cheers
Phil
Reply With Quote
Reply
  
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes
Postbit Selector
Switch to Vertical postbit Use Vertical Postbit

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

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Recent Posts - Contact Us - DSC Home - Archive - Top
Powered by vBulletin 3.5.4 - Copyright © 2000 - 2018, Jelsoft Enterprises Ltd. - © Ducati Sporting Club - All times are GMT +1. The time now is 04:28 AM.