Water/Coolant levels on a Chim
Discussion
All,
The question of where to re-fill the cooling system depends on how much cooling fluid you have lost. If you check the cooling system regularly and you ensure there is always some fluid in the expansion tank, then filling via the expansion tank is fine. If you have lost more fluid, then it is possible that air will have made its way into the swirl pot. It is then that you need to ensure the swirly pot is full as well.
Jamie.
The question of where to re-fill the cooling system depends on how much cooling fluid you have lost. If you check the cooling system regularly and you ensure there is always some fluid in the expansion tank, then filling via the expansion tank is fine. If you have lost more fluid, then it is possible that air will have made its way into the swirl pot. It is then that you need to ensure the swirly pot is full as well.
Jamie.
Hi Chris, next time you're near Halfords, pop in and buy a small bottle of antifreeze and a cheap antifreeze tester (a small hydrometer that'll tell you whether your water/antifreeze solution is up to strength - be careful not to drop it into the expansion tank though!).
chris watton said: Thanks guys,
have done it, only needed a measuring jug full of water, it's now just a tad over half way up the cylinder. I just used water this time, hope thats ok!!!!
Make up a top-up solution of the antifreeze to keep in your garage so you won't have to worry about adding just water.
I assume that there was some coolant visible in the expansion tank when you noticed it needed topping up. If it was completely empty, some air may have been sucked into the system, so....
In order to check whether you've got any air in the system - do the following.
It would appear you've got a Serpentine engine (consult the 'bible' to verify this), so with the engine cold, loosen/remove the blue cap on the expansion tank and top up to about half-full.
Remove the brass cap on the swirl tank and top up with coolant mixture - leave the brass cap off for the time being.
Loosen the bleed screw on the radiator (it is near the expansion tank on my car near the top of the rad), any air will be expelled and the level in the swirl pot will drop, nip the bleed screw up when coolant comes out. Keep an eye on the level in the ex-tank.
Top up the swirl tank to the top of the thread and replace the brass cap..
Check the level in the expansion tank is still ok and replace the blue cap.
If you had air in the system, you might notice the level in the ex-tank drop over a few days as air locks can occur, if the level drops again you may have to repeat this procedure.
Hope this is clear!
edited to recognise that jamiem has made the same points while I was busy typing!
>> Edited by wolosp on Friday 17th January 12:50
I would just like to add that it is possible to have the swirl tank half full and yet for the level to appear OK in the expansion tank. However, as I understand it, when the coolant gets warm, the air will expand and having no room to expand into, it will travel down the expansion tube into the expansion tank where it will rise above the coolant.
When the system cools down, the air in the swirl tank will cool and will suck in more coolant from the expansion tank which will then sink below the air. The net result is that there is less air in the swirl tank than before and less coolant in the expansion tank.
After a couple of heating/cooling cycles, the swirl tank will have refilled and the expansion tank will have dropped.
The easiest way to check for air in the swirl tank without removing the cap is to remove the blue cap on the expansion tank. You then give a gentle squeeze to the right hand radiator hose (looking towards the back of the car). This increases the pressure in the swirl tank and you should see the water level in the expansion tank rise slightly. When you let go of the hose, it will suck the coolant back into the swirl tank. If you see bubbles in the expansion tank when you squeeze the hose, then you have air in the swirl tank.
I'm happy to be corrected if I am wrong.
Ian A.
When the system cools down, the air in the swirl tank will cool and will suck in more coolant from the expansion tank which will then sink below the air. The net result is that there is less air in the swirl tank than before and less coolant in the expansion tank.
After a couple of heating/cooling cycles, the swirl tank will have refilled and the expansion tank will have dropped.
The easiest way to check for air in the swirl tank without removing the cap is to remove the blue cap on the expansion tank. You then give a gentle squeeze to the right hand radiator hose (looking towards the back of the car). This increases the pressure in the swirl tank and you should see the water level in the expansion tank rise slightly. When you let go of the hose, it will suck the coolant back into the swirl tank. If you see bubbles in the expansion tank when you squeeze the hose, then you have air in the swirl tank.
I'm happy to be corrected if I am wrong.
Ian A.
... liquids don't expand much when they get hot, only by a fraction of a percent. But gasses expand a lot when they get hot.
depends how hot - depends on the liquid - glycol mix is crucial to this - hence the 'expansion' tank - and those dried-on white streaks coming out the blue cap which you'd rather not see...the ones that gather at the foot of the rad to fool you into thinking your rad's gone...
Thank you again for all your very excellent advise, I am so glad I found this site, you guys have helped me immensely from helping choosing a Chim, to looking after it, and now consider this site an integeral part of TVR ownership!
I even had a very nice email from Steve Heath, saying he will arrange a replacement 'bible' for me, after I said the binding was wrong on my copy! What a top guy!
Chris
I even had a very nice email from Steve Heath, saying he will arrange a replacement 'bible' for me, after I said the binding was wrong on my copy! What a top guy!
Chris
tantivy said:
... liquids don't expand much when they get hot, only by a fraction of a percent. But gasses expand a lot when they get hot.
depends how hot - depends on the liquid - glycol mix is crucial to this - hence the 'expansion' tank - and those dried-on white streaks coming out the blue cap which you'd rather not see...the ones that gather at the foot of the rad to fool you into thinking your rad's gone...
train spotting time ... 50:50 ethylene glycol water mixture has a thermal expansion coefficient of about 0.03% per degree centigrade ... if I remember right, the volume of the cooling system is about 12 litres, so heat it by 80 degrees and you'd get an increase in volume of 0.29 of a litre, which is slightly less than a can of coke.
Sounds good to me ATG (:blinded by science: 
) - my problem was when I once hit 115+ on the temp gauge because my twin fan 40amp fuse had blown & that very day I'd topped up the system to Steve's recommended "within 2 inches of the top" bible-1 guidelines. A can & a half of coke (or even 7up) would certainly have done it since my mix was too rich in glycol anyhow!! cheers, T 
) - my problem was when I once hit 115+ on the temp gauge because my twin fan 40amp fuse had blown & that very day I'd topped up the system to Steve's recommended "within 2 inches of the top" bible-1 guidelines. A can & a half of coke (or even 7up) would certainly have done it since my mix was too rich in glycol anyhow!! cheers, T The way I read steve's bible he means 2 inches from the top of the swirl pot (I fully admit I find the paragraph a bit confusing so I could be wrong ... Steve are you out there?).
If you fill the expansion chamber to within 2 inches of the top, you haven't got enough air left in it to absorb the expansion of the coolant (and any other small pockets of air in the rest of the system) ... at which point you get the great green Vesuvius effect, or the Old Faithful steam treatment. Happened to me too. 12 litres makes a lot of steam
If you fill the expansion chamber to within 2 inches of the top, you haven't got enough air left in it to absorb the expansion of the coolant (and any other small pockets of air in the rest of the system) ... at which point you get the great green Vesuvius effect, or the Old Faithful steam treatment. Happened to me too. 12 litres makes a lot of steam
Bible 2 has gone into a long long explanation. The cooling chapter grew by 14 pages compared to Bible 1. There are some cars that like the two inch and some that don't. My first Griff was a two incher, current one is a bottom of the tanker. There are some inbetween. Find out what is good for your car and use that.
The TVR docs say two inches BTW. I think they just wanted to ensure people kept them filled.
Steve
www.tvrbooks.co.uk
Steve
>> Edited by shpub on Monday 20th January 14:26
The TVR docs say two inches BTW. I think they just wanted to ensure people kept them filled.
Steve
www.tvrbooks.co.uk
Steve
>> Edited by shpub on Monday 20th January 14:26
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