I have just got my coolant tank and radiator replaced after a leak in the radiator and a cracked coolant tank. I filled the coolant tank last month and now it is nearly empty. I am just wondering if it is normal to lose a lot (like is it getting into the system) or do I have another leak? Thanks
They may not have bled your cooling system properly
As a possibility, if you had air trapped in your cooling system it would expand as the engine approached operating temperature.
It would eventually, hopefully, make it's way into your radiator where the air would get released into the overflow tank by a valve that opens with higher pressures.
As the engine cools a vacuum from any remaining air would be created in the cooling system as any remaining air pockets contracted. This negative pressure would draw in coolant from the overflow giving you the appearance that you have a coolant leak.
If you are not seeing any leaks, ensure your coolant overflow is filled to the appropriate quantity by referencing the fill lines on the side of the reservoir. Any remaining air should purge itself through the designed process. So long as your car is not overheating and losing coolant IMO this is more than likely the process that is occurring.