quick question expansion tank

[sternal]

Having had a new Rad fitted today I have just checked the levels

The tank behind flap in on Min

and

the tank in engine bay is full but not right to the top say 2cm from the top.

As Im taking the van to work in the morning (before the garage is open so I can't ask them) should I top direct so its right to the top ?

I will check before I leave in the morning

Thanks in advance

[Plasticman]

lets assume they have bled it correctly top up behind flap to min-max is fine ,other should be full. in practice it ius a touch below brimmed but again if not bled right then you will notice on the run to work , (many miles ?)
mm

[sternal]

drive home from garage was 4 miles then when I got home i let it run for 30 odd mins till fan cut in temp needle didn't go over half way during this time.

I did open it after about an hour and it was full a bit spilled out prob cos it was still hot !

Its been sitting for 6 hrs so its cooled down now...

Drive to work is 7 miles London traffic !

[Ralf85]

Even if it has been bled properly it will still take time for all the air to bleed out, so you will need to top up a small amount over the next few weeks. Then it will settle down.

[sternal]

Even if it has been bled properly it will still take time for all the air to bleed out, so you will need to top up a small amount over the next few weeks. Then it will settle down.

into which tank ? sorry for sounding so thick

thank you for responses

[Ralf85]

Even if it has been bled properly it will still take time for all the air to bleed out, so you will need to top up a small amount over the next few weeks. Then it will settle down.

into which tank ? sorry for sounding so thick

thank you for responses

Top up the tank behind the flap.

[sternal]

okay thanks kind sir and it won't matter that the pressurised tank isn't to the brim ?

I'm asking as knowledge is good.

[Ralf85]

The coolant in the expansion tank tops the other tank up. You may need to use up to a litre of 50/50 mix of antifreeze/water over the next 50 odd miles.

[sternal]

I'm just asking so how comes the water from behind the flap is on min and the other tank is down 2 or so cm how comes the water from behind the flap hasn't all been sucked up to make the other tank full ? or would this only happen when the water is hot ? thus needing to fill tank behind flap

so before I set off I will fill behind the flap to max

[sternal]

lloydy where did your post go ? its disappeared !

okay got you I think !

So why and not that I'm going to put water into the engine tank be a NO NO ? and I'm talking not very much

again I'm not going to do this but why wouldn't that be done ?

[MGP]

When the coolant heats up it expands which is what makes the system pressurise (the system is pressurised to raise the boiling point as the running temp is near the unpressurised boiling point) which may push a little cooland out into the top up tank. When the system cools back down and contracts any coolant pushed out should be sucked back in through the darlek cap, so you said the header tank was full to the brim when hot so the logical conclusion is that the pipe between the two tanks is perished and allowing the system to draw in air as it cools as its easier to draw up air than coolant.

Hopefully that makes some sense.

[MGP]

Possibly the darlek cap? The seal on the level sensor?

[sternal]

thanks for answers MGP just had new Rad fitted hence the refilling, hose isn't perished as I replaced about 10 months ago good call with darlek cap will see how it goes over the next few days.

can't hurt to change cap anyhows

[lloydy]

lloydy where did your post go ? its disappeared !

okay got you I think !

So why and not that I'm going to put water into the engine tank be a NO NO ? and I'm talking not very much

again I'm not going to do this but why wouldn't that be done ?

No idea where it went? But I wouldn't worry too much, just keep the top up tank at the full mark and it will settle down after a few journeys. As long as your not overheating all sounds pretty normal.

[ghost123uk]

can't hurt to change cap anyhows

If buying a new Dalek cap, best get it from Brickwerks as some of the other well known suppliers sell inferior ones, and you don't want inferior parts on a WBX cooling system