expansion bottle issues

[firemansam1066]

folks, i have tried to find out through the search facility but getting bogged down

if i top my surf up in the morning, about 1 pint of water, and drive say 30-40 miles, when i get there its spilling water from the overflow on the expansion bottle, when i look under the bonnet the bottle is full but when its cooling down its not sucking enough water back in, is it just a case of a new cap or is it the thermostat, or indeed, both?

thanks again folks.

[stormforce]

folks, i have tried to find out through the search facility but getting bogged down

if i top my surf up in the morning, about 1 pint of water, and drive say 30-40 miles, when i get there its spilling water from the overflow on the expansion bottle, when i look under the bonnet the bottle is full but when its cooling down its not sucking enough water back in, is it just a case of a new cap or is it the thermostat, or indeed, both?

thanks again folks.

renew them both at the same time and give the coolant a good burping to ensure there's no air locks

[TonyN]

If its not sucking water back the top hose is normally pinched in when its cooled down.

Fit a new cap and stat first, anything else is gonna be traumatising to the wallet.



Don't overfill the expansion tank, the full line is half way up the bottle.

[BUSHWHACKER]

Check along the top of the radiator for signs of leaks. They may not be noticable when the rad is cold, but open up when hot and they're sucking in air instead of coolant from the expansion bottle when you switch the engine off and it cools down.