Missing hose?

[Throbbinhood]

Mainly at @dom14 and @mudski as they have rb30's, but maybe the same across other models.

The yellow cap that screws onto the overflow bottle. Is there a hose that runs from the inside of the cap, down to the bottom inside the overflow bottle?

I always seem to be missing about 30ml of coolant. Never more, even after a full weekend of driving. Thinking the system is warming up, pressurising as it should, rad cap relieves pressure to overflow, but when cooling down its sucking air back in instead of coolant (as there is no hose from the overflow cap to overflow coolant). I can't see how the yellow section of the cap is long enough to reach the coolant without a hose.

Am I right that I'm missing a hose here, or have I lost the plot?

[Bigcol]

I know mine (TD42) has a hose from that cap lid that goes almost to the bottom of the tank - about 15mm off the bottom

[mudnut]

You're right. There is a hose needed, as that is how it works. The small bit released by the cap, under pressure, is stored in the overflow bottle and is drawn back into the system via the spring loaded valve in the cap as the system cools. The hose acts like a straw.

[mudski]

Mainly at @dom14 and @mudski as they have rb30's, but maybe the same across other models.

The yellow cap that screws onto the overflow bottle. Is there a hose that runs from the inside of the cap, down to the bottom inside the overflow bottle?

I always seem to be missing about 30ml of coolant. Never more, even after a full weekend of driving. Thinking the system is warming up, pressurising as it should, rad cap relieves pressure to overflow, but when cooling down its sucking air back in instead of coolant (as there is no hose from the overflow cap to overflow coolant). I can't see how the yellow section of the cap is long enough to reach the coolant without a hose.

Am I right that I'm missing a hose here, or have I lost the plot?

Yes. As Mudnut has said it needs this hose to draw back the coolant when it cools....

[Throbbinhood]

Thanks guys. I seem to missing this straw. Explains everything. Two years I've searched for this issue. Sigh. Time to find some hose.

[mudski]

Thanks guys. I seem to missing this straw. Explains everything. Two years I've searched for this issue. Sigh. Time to find some hose.

haha! Always the way hey? Something so simple can cause so much grief. The hose isn't sitting in the bottom of the tank?

[Throbbinhood]

Could anyone do me a favour and measure the length of their straw? Save me cutting it 10 times to get the right length.

[Throbbinhood]

haha! Always the way hey? Something so simple can cause so much grief. The hose isn't sitting in the bottom of the tank?

Nah not that I can see. AFAIK it's never been on the car since I've owned it, probably why it never popped into my head that it was missing. Few beers and a lot of thinking about it and it popped into my head after seeing one on another car.

[mudski]

Could anyone do me a favour and measure the length of their straw? Save me cutting it 10 times to get the right length.

Would really matter, as long as its below the low mark on the tank....

Nah not that I can see. AFAIK it's never been on the car since I've owned it, probably why it never popped into my head that it was missing. Few beers and a lot of thinking about it and it popped into my head after seeing one on another car.

Yeah beer does wonderful things hey.

[mudnut]

Mainly at @dom14 and @mudski as they have rb30's, but maybe the same across other models. here, or have I lost the plot?

Definitely lost the plot! Since when does Mark own a dirty 30? :P