So I have had a message flashing up on my screen saying coolant level low but it isn't, I have read this was a common fault and the float fills with coolant.

Question, can the sensor just be replaced or is it sealed within the expansion tank?

Thanks 2008 RRS 2.7TD in Stornoway grey, black leather and 22 inch alloys
Xtrons Android head unit

The float is within the tank and can’t be replaced.

About £25 for new tank

Ok thanks andy, thought I would ask as can buy a tank with sensor on fleabay but you can also buy the sensor separately 2008 RRS 2.7TD in Stornoway grey, black leather and 22 inch alloys
Xtrons Android head unit

Sensor is "specific gravity" sensitive, so if coolant does not have enough % of antifreeze it will trigger coolant low warning.
float can get stuck on the bottom of the tank , my did. remedi was to remove it and wash with some gasoline until you here flot ratell. wash with detergent and refill with antifreeze. it did work for me.
 RR 2012 4.4 TDV8

OK cool thanks 2008 RRS 2.7TD in Stornoway grey, black leather and 22 inch alloys
Xtrons Android head unit

took bottle out and the float was fine and moved freely but the sensor looked dodgy, £8 for a new sensor and job done, no more "coolant level low" messages  2008 RRS 2.7TD in Stornoway grey, black leather and 22 inch alloys
Xtrons Android head unit

 RR 2012 4.4 TDV8

M9G,


did you get the message constantly or did it keep coming on for a bit then resetting again?
As this is the issue I have but i already placed the tank so maybe need a new sensor.

I've been having the same message pop up randomly for a while now, have ordered the temperature sender as a stand-alone item, hopefully can just replace it rather than having to replace the whole bottle - can't see why they'd sell the sensor separately if you can't!

The issue as I understand it is with the float inside the bottle becoming saturated and not floating as it should.
The sensor is a separate item. The float is built into the bottle itself.

Majority of the time, it isn't the sensor itself but the float within the coolant bottle. If you fill the bottle with water and the float doesn't rise, that's your issue.