Hi,
Just bought a 650L upright tank and have fitted it in. Just filled it right to the top for the first time today and set off for my day's work. Got to my first job which is only 5mins away from my house and the back of the van was soaked!

My lid has a vent on it and I can only assume that this is where the water came from as it was wet around it?
How can I prevent this from happening everytime I fill it right up?
Anyone else have this problem?
Cheers
Mattie