Coolant bottle cap faulty
 

Hi my daughter has a 2002 V6 Freelander, it had a leaking cap on the coolant bottle when the cap was tight, I backed it off a little and it stopped leaking. Next time it went in for service I asked that they check the cooling system. They replaced the bottle because of cracks and also the cap. All was good for 2 months until the daughter removed the cap to top up the coolant when the new cap fell appart in her hand. It appears that it has been effected by heat (although temp gauge is never over midway) and it lost it's shape allowing it to fall to peices. Any ideas would be appreciated. Thanks Trev