coolant

[whitebob]

If I park facing up hill, the coolant runs back into the refill tank. Is there a non return valve not working or something? I do have a slightly blown cylinder head gasket, if that has something to do with it. Presumably it was creating an air lock, which I can get rid of by loosening the bleed screw on the radiator, which is a nuisance. Water boxer 1990.

[itchyfeet]

yes non return valve is called a coolant cap, usually the blue darlek type.

The blown head gasket will mess up the system by adding combustion gasses which creates the same as air in the system.

You can't really have a slightly blown head seal, like you can't be slightly dead Time to get it fixed.

[Mocki]

Itchy, I’m surprised at you !
Not head gasket , water jacket seal or o rings !

[itchyfeet]

I was just repeating the op so he under stood me, you will notice I soon rephrased it.

You have to meet people half way then re educate them.

You can't really have a slightly blown head seal.

[itchyfeet]

I feel a picture coming on ...

[whitebob]

Thanks very much everybody for the advice.