Swirl pot/header tank issues??

[fullthrottlehyde]

So quick question, just recently got a 3000m. I don't know if this is standard but I have a quite basic pressurised radiator system with a main swirl pot and overflow system. I have replaced all the hoses and the water pump works fine, I have filled the swirl pot and the overflow( to half way) but when I start and run the car water comes out the top of the swirl pot even before it comes up to temp, it has a brand new cap aswell. Do these normally leak? I can't see any reason why it should, just for information the thermostat seems to work and water gets round the system as all the pipes are hot, just throws water out the top of the header tank/swirl pot etc



Any suggestions?

[chris52]

You will no doubt have the wrong cap on the swirl pot. The cap you need should have a double seal, an Inner and outer seal is required or it will just flow out.
Chris

[Cerberus90]

We've just got a blanking cap on the swirl pot, and the pressure cap on the expansion tank.

[fullthrottlehyde]

I have a blanking cap on the swirl pot and a pressure cap on the overflow

[chris52]

Mine has a pressure cap on both. That's how it came to me. But a blanking plate on the swirl pot would work just as well. I'm assuming that the OP has a pressure cap on that only seals on the inner seal and not the outer.
Chris

[chris52]

fullthrottlehyde said:

I have a blanking cap on the swirl pot and a pressure cap on the overflow

If it's leaking past the outer seal then the seal or cap is no good that can be the only explanation or you have a bigger problem where excess pressure is building up in the system forcing the coolant out.

[fullthrottlehyde]

On the blanking cap, underneath it's a solid piece of rubber, this sounds like it could be wrong. What should the double seal item look like and why do the 2 seals make a difference?

[prideaux]

fullthrottlehyde said:

On the blanking cap, underneath it's a solid piece of rubber, this sounds like it could be wrong. What should the double seal item look like and why do the 2 seals make a difference?

Yes the swirl pot cap is one seal solid piece of rubber and if you fill the swirl pot and half the expansion tank half full I would expect that to happen until it finds its own level in the swirl pot.
I tend to fill the swirl pot and none in the expansion tank then after a run the swirl pot has found its level and transferred any excess to the expansion tank each find there own level the swirl pot tends to find a level about 6 inches down from the top.
Andrew

[chris52]

Chris

Edited by chris52 on Friday 1st November 10:05

[chris52]

Mine does not have a solid rubber cap on the swirl pot it has a double seal one that seals the base of neck via a pressure spring same as the expansion tank and one that seals the upper/outer neck of-the swirl pot . I don't know if this is correct but seems to work well.
To the OP when you say it's leaking I presume you mean that water is leaking past the seal and down the outside of the swirl pot ? If this is the case then there is a problem most Ilkley just a bad seal. If it's just going into the expansion tank then this is correct.
Chris

Edited by chris52 on Friday 1st November 10:06

[prideaux]

chris52 said:

Mine does not have a solid rubber cap on the swirl pot it has a double seal one that seals the base of neck via a pressure spring same as the expansion tank and one that seals the upper/outer neck of-the swirl pot . I don't know if this is correct but seems to work well.
To the OP when you say it's leaking I presume you mean that water is leaking past the seal and down the outside of the swirl pot ? If this is the case then there is a problem most Ilkley just a bad seal. If it's just going into the expansion tank then this is correct.
Chris

Edited by chris52 on Friday 1st November 10:06

If it works ok but not correct you have two pressure caps which does not make sense one pressure one none pressure is the correct system I have experimented with no pressure cap at all ie having no expansion tank at all as I use evans coolant which creates no pressure at all as its boiling point is 180 degrees and it worked however I put it back to OE as should there be a leak when away and I have to fill up with water then I would need the expansion tank.
A

[chris52]

prideaux said:

If it works ok but not correct you have two pressure caps which does not make sense one pressure one none pressure is the correct system I have experimented with no pressure cap at all ie having no expansion tank at all as I use evans coolant which creates no pressure at all as its boiling point is 180 degrees and it worked however I put it back to OE as should there be a leak when away and I have to fill up with water then I would need the expansion tank.
A

I understand where your coming from but it actually only has one pressure release point that being the one on the expansion tank. The one on the swirl pot will only seperate the flow from the swirl pot to the radiator (small gauge pipe that comes from the O/S top of the radiator) and expansion tank now this is probably wrong and perhaps I should stick a solid one on instead? Having only ever done about 100 miles in total I dont want the set up I have at the moment causing problems.

Chris

[Cerberus90]

What is happening by having two pressure caps I think is, that you won't get anything going into the header tank until the pressure valve on the swirl pot releases, I would imagine that would include any air too, which would be better to have in the header tank rather than the swirl pot possibly.

[heightswitch]

The diagram exhibits a header tank (the swirl pot) and catch tank?
The header tank (tall one) normally needs a pressure cap. In the event of the pressure cap lifting the excess water will flow to the catch tank and not overflow?

An expansion tank is bottom fed to allow excess water to back flow into the cooling system?? Unless their is a tube in the catch tank to allow back siphonage and it is always the highest point in the system..
Looking at the diagram further I would also question that the main tank is a swirl pot??

The bleed connection from the radiator to the neck of the header tank confuses the picture somewhat and would lead me to deduce further that a sealed cap should be placed and pressure cap in the catch tank.

A swirl pot has an inlet and outlet designed to promote swirl and a permanent bleed to allow air to return to the top of the header. The diagram doesn't show that.

so neither an expansion tank or swirl pot.

This is a swirl pot


N.

Edited by heightswitch on Friday 1st November 18:55

Edited by heightswitch on Friday 1st November 19:02

Edited by heightswitch on Friday 1st November 19:13

[Cerberus90]

Inside the catch tank there is a pipe which goes down to the bottom of the tank.


Toooo much terminology,

[Adrian@]

Back to basics (this is a 3000M as opposed to Taimar or 3000S)..the tower has a blank cap (simply rubber seal) and the expansion has a 13lb pressure cap of the correct version (they can vary in the depth of the cap) BUT a question... What is happening with the heater and the assoc pipe from the rear of the pump, choke, T pieces and T piece WITH vent and the a-joining pipe that has a restrictor inside AND heater valve. IF this is not vented correctly then air in the system will do all it can to push water out regardless of what is happening with caps.
Adrian@

Edited by Adrian@ on Friday 1st November 19:49