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Coolant flow question

Posted: 05 Mar 2011, 10:43
by psychonaut
Right, before i commit myself to the local loony bin, can someone please tell me I've got this right, or more importantly, I've mad a horse's ar-se of the whole show.

Coolant flow is from the pump, to the bottom of the rad, and then from the top of the rad back to the head, yes?

I ask because my rad seems to be getting warm from the top down, and at the bottom is as cold as my Mrs when I get back in from a good night at the rugby club. The pipe from the pump towards the front of the van is cold at the engine bay end when i touch it, but the return from the rad to the head is warm. The system is bleeding absolutely fine, although didn't seem to take as much as I thought she would.

Am i going mad - have i connected the pipes up the wrong way round? Or do I just need to carry on bleeding her? I've followed the instructions in the wiki to the letter.

ETA - 1.9 1Y, early 'CS' type radiator, and push and twist header tank and cap

Ta

Re: Coolant flow question

Posted: 05 Mar 2011, 11:55
by psychonaut
I've answered my own question - I've got the pipes connecterd the wrong way around - should be from the pump to the top of the rad, and so on and so on... Only me....

Re: Coolant flow question

Posted: 05 Mar 2011, 14:11
by psychonaut
And then, make sure you've done the jubilee clip underneath the van properly. Else your expensive coolant from Mr Baxter will end up all over your garage floor. That'll be no movement on the van till some more coolant arrives from the Brickwerks emporium then....

Re: Coolant flow question

Posted: 05 Mar 2011, 18:50
by kevtherev
I'll get a pic hang on....
pipes are to the bottom of the rad and can be mixed up
as you can see it should flow from the bottom up... which is different to normal radiators
Notice the baffle to stop the cooled water mixing back with the hotter stuff

Image

Re: Coolant flow question

Posted: 05 Mar 2011, 19:15
by psychonaut
Many thanks Kev, you are a star

Re: Coolant flow question

Posted: 05 Mar 2011, 19:35
by kevtherev
With further thought
I think this picture is wrong...
The bleed screw is best placed to catch incoming water and trap it there rather than after the coolant has travelled through the rad
Or would it cause lock

anyone else think this?

Re: Coolant flow question

Posted: 05 Mar 2011, 20:00
by Mocki
i know these images are for a wbx, but
Image

Image

answers the question i think

Re: Coolant flow question

Posted: 05 Mar 2011, 20:01
by psychonaut
Kev, I think this is the later rad too, mine is the earlier type with the two seperate fan switches on the side. Do you know if it's laid out the same internally?

And so long as the bleed screw was left open during the initial priming of the system, would that get around the potential airlock problem you describe above?

Re: Coolant flow question

Posted: 05 Mar 2011, 20:04
by psychonaut
Thanks Mocki - that shows the set-up to be the same as the first pic Kev posted, so I'm confident mine is plumbed in correctly now But it's easy to see how the system can be a bit of a booger to bleed

Re: Coolant flow question

Posted: 05 Mar 2011, 20:37
by colinthefox
psychonaut wrote:Coolant flow is from the pump, to the bottom of the rad, and then from the top of the rad back to the head, yes?

No. The pump is on the RETURN. The flow from the pump goes through the engine then around three loops. One is the heater loop, one is the bypass loop, and one is the radiator loop. This might help unscramble your brain. But I've no idea whether the flow goes to the top or the bottom of the rad.

Re: Coolant flow question

Posted: 05 Mar 2011, 20:51
by psychonaut
Thanks Colin. Between you and Kev and Mocki, you have unscrambled my brain.

However, I am now scrambling it again with Welsh scrumpy

Re: Coolant flow question

Posted: 05 Mar 2011, 21:08
by kevtherev
So any air goes through the rad and is trapped at the exit

OK so the pic is correct... and the rad will warm at the bottom first

Re: Coolant flow question

Posted: 08 Mar 2011, 22:52
by psychonaut
System filled and bled today, and took the van for a test drive, just a few miles around local roads, and the needle didn't go past halfway, so I think that's looking good Many thanks to all who contributed helpful advice, both on here, via PM, on the phone, and on Facebook

One last question. I replaced the header tank with one from the Brickwerks Emporium. The old one kind of sat in a couple of slots to the front of the battery tray, but the new one has no such fitting. Did newer vans have a bracket there to fit the later design header tank onto, or is everyone doing the same as me and cable-tieing the header tank into position?!

Thanks again

Re: Coolant flow question

Posted: 08 Mar 2011, 23:45
by Cruz
later tanks had a different bracket

025-121-409D

Re: Coolant flow question

Posted: 08 Mar 2011, 23:51
by psychonaut
Thanks Cruz - do you happen to know if it's still a dealer item, or can I get it someplace else?