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Header Tank plumbing help
Jasper - 2/5/06 at 12:42 PM

Never quite got my head around this one.

I have a closed system header tank (?) with two pipes going in (plus the overflow) - one at the top, one at the bottom.

So where exactly do I have to plumb them in? I have flexi pipes to any from the rad (top and bottom) and to and from the heater matrix - both of which could take a t-piece.

NS Dev - 2/5/06 at 12:56 PM

Basically the one from the bottom of the header tank wants to go to a low point in the system (so a tee into the bottom hose won't go far wrong) and the top of the header tank wants to be connected to the very highest point in the rest of the system (top of the tank itself needs to be the absolute highest point) so that any air bleeds to the header tank.

Any high spots in the system that can trap an air pocket also need teeing into the bleed to the top of the header tank.

Follow that guide for any engine and it won't be far wrong.

Jasper - 2/5/06 at 01:04 PM

Thanks mate - it's kind of what I thought - but I never like to trust myself without checking first

Hellfire - 2/5/06 at 03:07 PM

quote:
Originally posted by NS Dev
Basically the one from the bottom of the header tank wants to go to a low point in the system.


Could I ask why it needs to go to a low point? I have heard this from numerous commentators but I've never heard a reason as to why?

MikeR - 2/5/06 at 03:40 PM

yeah i'm a bit nervous now.

Mine goes into a T between the water pump and cylinder head. Rational being it was easy and the engine would get water in an emergancy even if the thermostat is closed.

(hey, i liked that justification, even if it was made up)

Fred W B - 2/5/06 at 06:44 PM

I've read (carrol smith) that you want the feed from the header tank to be just upstream of the water pump inlet, to help make sure the water pump has a solid head of deairated (spelling?) water in front of it. Makes sense to me.

Cheers

Fred WB

MikeR - 3/5/06 at 10:45 PM

sounds like what i've got

NS Dev - 3/5/06 at 11:03 PM

quote:
Originally posted by Hellfire
quote:
Originally posted by NS Dev
Basically the one from the bottom of the header tank wants to go to a low point in the system.


Could I ask why it needs to go to a low point? I have heard this from numerous commentators but I've never heard a reason as to why?


Just to help when filling up, that's why I've done it that way. If you drop the water into a low point in the system, it's under the air and just pushes it into the header tank and out of the way, if it's higher up it just makes filling slightly more difficult, that's all, no real problem.

As for the de-aerated water near to the pump, maybe/maybe not, who knows and who could find out anyway! As long as the car stays cool no probs.

I've never put a system together yet that needed any technical bleeding on the system, and having spent 1/2 hour getting air out of a 1400 pug 205 it looks like I have done better than at least one major manufacturer on that point!

nick205 - 5/5/06 at 09:47 AM

ditto on the Pug engines - always a PIA to get air free. good little engine IMHO tho'

greggors84 - 5/5/06 at 12:01 PM

I think my Pug 106 has about 5 air bleed points, its a right bugger to bleed properly!