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Coolant issues

Posted: 27 Jul 2020, 16:39
by Stesaw
Sorry slight hijacking on your thread but it seems I am getting the opposite, on my recent jaunt up norf and back I've noticed on my van the expansion tank is chock full but doesn't go back into the topup tank, seems to pull from the top up but doesn't flow back in. Not done that before in the past, the cap is brand new blau one,  Doesn't appear to be any leaks anywhere either.  :|  

Oh, no airlocks, heaters work fine and the rad is evenly hot when running. Checked to make sure but only coolant from bleed screws.

Haven't started it today, maybe I should be looking for white smoke or smell of coolant from the exhaust?

Re: Heads Off Due To Pressurised Coolant

Posted: 27 Jul 2020, 16:55
by Mocki
Stesaw wrote: 27 Jul 2020, 16:39 Sorry slight hijacking on your thread but it seems I am getting the opposite, on my recent jaunt up norf and back I've noticed on my van the expansion tank is chock full but doesn't go back into the topup tank, seems to pull from the top up but doesn't flow back in. Not done that before in the past, the cap is brand new blau one,  Doesn't appear to be any leaks anywhere either.  :|  

Oh, no airlocks, heaters work fine and the rad is evenly hot when running. Checked to make sure but only coolant from bleed screws.

Haven't started it today, maybe I should be looking for white smoke or smell of coolant from the exhaust?
Surely you just need to fill the top up tank up to the level ? The header tank should be full to the brim when cold , if it then heats up and pushed the coolant out to the top up tank , it cannot go anywhere else , if the header tank is then fulll to the brim when cold again, it’s sucking it back as it should ? Or am I getting the wrong end of a stick here ? 
 

Re: Heads Off Due To Pressurised Coolant

Posted: 27 Jul 2020, 17:29
by Stesaw
Mocki wrote: 27 Jul 2020, 16:55
Stesaw wrote: 27 Jul 2020, 16:39 Sorry slight hijacking on your thread but it seems I am getting the opposite, on my recent jaunt up norf and back I've noticed on my van the expansion tank is chock full but doesn't go back into the topup tank, seems to pull from the top up but doesn't flow back in. Not done that before in the past, the cap is brand new blau one,  Doesn't appear to be any leaks anywhere either.  :|  

Oh, no airlocks, heaters work fine and the rad is evenly hot when running. Checked to make sure but only coolant from bleed screws.

Haven't started it today, maybe I should be looking for white smoke or smell of coolant from the exhaust?
Surely you just need to fill the top up tank up to the level ? The header tank should be full to the brim when cold , if it then heats up and pushed the coolant out to the top up tank , it cannot go anywhere else , if the header tank is then fulll to the brim when cold again, it’s sucking it back as it should ? Or am I getting the wrong end of a stick here ? 
Header full to brim when hot and cold, doesn't push coolant into topup. Have drained the topup tank as well as a test to see if it pushes coolant into it when warm. It doesn't, but as it pulls from the topup the cap couldn't be shot could it? 

Re: Coolant issues

Posted: 27 Jul 2020, 18:13
by Mocki
I would be changing the cap ..... 

Re: Coolant issues

Posted: 27 Jul 2020, 18:43
by Stesaw
That will suck if the caps knackered its new and I purposely avoided the cheap tat ones. I have got a spare to try so will give that a go.

Re: Coolant issues

Posted: 27 Jul 2020, 18:48
by R0B
Where did you buy your cap? eBay has some dodgy ones.

Re: Coolant issues

Posted: 27 Jul 2020, 20:26
by Mocki
Even new can be faulty sometimes , never ever ignore a component just because it’s new 

Re: Coolant issues

Posted: 27 Jul 2020, 20:51
by Stesaw
R0B wrote: 27 Jul 2020, 18:48 Where did you buy your cap? eBay has some dodgy ones.

I bought it from either Brickwerks or JK. I'd have to check my order history. 
 
Mocki wrote: 27 Jul 2020, 20:26 Even new can be faulty sometimes , never ever ignore a component just because it’s new

Yeah I know all to well about that with computer components. Will be typical luck that when I buy a "quality" part it's the bit that craps out within a few months. :roll:

Re: Coolant issues

Posted: 27 Jul 2020, 21:19
by Mocki
The quality remains to be seen .......
I bought it from either Brickwerks or JK. I'd have to check my order history

Re: Coolant issues

Posted: 27 Jul 2020, 21:34
by Stesaw
Mocki wrote: 27 Jul 2020, 21:19 The quality remains to be seen .......
I bought it from either Brickwerks or JK. I'd have to check my order history

:lol:

Was from JK, but from what I saw Brickwerks sell the same thing from the same manufacturer. 

Re: Coolant issues

Posted: 01 Aug 2020, 17:27
by Stesaw
Just an update had a bit of time to look at the van today so checked the coolant level from cold again. Was full and when I unscrewed the cap it was pressurized and coolant came out as it was overflowing. I've swapped the cap over to one of the spares I have to see if that helps. Ran the engine up to temp and it was pushing coolant into the top up tank, so maybe it was a dodgy cap afterall.

Doesn't appear to be any leaks anywhere at all that I can see. But if the cap doesn't cure it more investigations I guess.

Re: Coolant issues

Posted: 01 Aug 2020, 19:12
by Mocki
If it was still pressured when cold , it’s pretty sure thing that there isn’t any leaks , or it would have lost pressure ?? 

Re: Coolant issues

Posted: 01 Aug 2020, 19:35
by Stesaw
Mocki wrote: 01 Aug 2020, 19:12 If it was still pressured when cold , it’s pretty sure thing that there isn’t any leaks , or it would have lost pressure ?? 

True  :roll:

It shouldn't be under pressure when cold though correct?

Re: Coolant issues

Posted: 01 Aug 2020, 19:36
by 937carrera
Correct

When the coolant cools it contracts, giving more space for the air and reducing the pressure again.

Re: Coolant issues

Posted: 01 Aug 2020, 20:21
by Stesaw
OK, so guessing the cap is duff then for it to keep the pressure?
I've swapped it anyway so will see what happens.