Loosing Water from Radiator Overflow

[Purbeckfossil]

Hi all. New Radiator cap fitted. Loosing about a pint of water on 12 mile run from overflow. I have started engine from cold and run it up to temperature with rad cap off, then increased throttle to see if any pressure blowing out of radiator but that is A-OK. Rad is filled to about 1 inch below neck. Don't know if failed stat would come into the equation or how to test if applicable. Any suggestions appreciated before head comes orff!

Thanks

[katy]

If you don't top up the rad, does the level keep dropping and dropping? Or does it stabilize at a certain level? If so, you've been putting too much water in it.

[bmcecosse]

Stick a plastic bottle under the overflow pipe - then when it cools down it will suck the water back in.... How's the negine temperature when running? Does the heater work VERY well ??Or - more worryingly - not at all.......?

[chrisryder]

BMC, how does it suck water back in? what about the rad cap?

[bmcecosse]

It has a vacuum breaker valve........

[Purbeckfossil]

Thanks for your various inputs.

I have now fitted a bottle on the overflow and there is about 1/2 pint overflow, most of which is sucked back in on cooling. On checking the radiator cold, the volume is nicely around the top of the vanes. So, my question is:- should an overflow bottle be permanently fitted or should it have been there all along as the water loss appeared much larger in volume when allowed to vent free. I currently have a 1L tesco milk bottle in place (not exactly concours) - Cheers

[bmcecosse]

It's not doing any harm there - just use a more aesthetic bottle !

[moggydriver62]

Johnnie Walker bottle would look nice.

[Neil MG]

Thanks for your various inputs.

I have now fitted a bottle on the overflow and there is about 1/2 pint overflow, most of which is sucked back in on cooling. On checking the radiator cold, the volume is nicely around the top of the vanes. So, my question is:- should an overflow bottle be permanently fitted or should it have been there all along as the water loss appeared much larger in volume when allowed to vent free. I currently have a 1L tesco milk bottle in place (not exactly concours) - Cheers

It always looks like more when it's all over the floor!

Without the bottle it will stabilize and you don't need to keep topping up. leave the bottle until you are happy you don't have a leak. Then you can take it off and forget about it!

[bmcecosse]

The bottle is an excellent fitment - no need to remove it - just make it tidy!