Coolant bottles
 

Evening all..

What is the best way to clean out a very dirty coolant bottle, looks as though mine has gone through 437423472 head gaskets and needs a dire clean!

Thanks.

drop a dish washer tablet in, run the car for a few miles and change the coolant.

Take it off, seal it shut and fill it with 40 degree water and bio washing powder, then leave it fora few hours. If you want to clean oil out of your system after an HG failure, there's a additive available, IIRC its just citric acid powder - run it through in clean water then drop the rad and fill back up with coolant.