thanks.
1 a non return valve is unlikely as it drains in the same direction as the pumped flow.
2 the cap has a breather to prevent a vacuum forming,so
sealing it would create problems.
but thanks for replies.
colin m
colin m
April 2011
Don't fill it to the top, make sure the top is on securly and seals the neck, park facing downhill?
arizona kid
April 2011
There is a non return valve in the pipe,it is probably stuck.
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