Webasto Air Top 2000 ST Diesel heater - leaking diesel fuel tank

Hi Ian,

Is it a "leak"or is it just diesel venting from the vent hole in the cap? I too have a diesel heater with a 10L tank and there is occasionally a dust trail where fuel has come out of the vent hole.

Cheers

Captain

I fitted our tank inside the Oka, to do it I cut the threaded section of the filler neck off and used a bit of silicone hose to extend the neck to the outside and then refitted the end and cap externally and it does the same.
You will have to expect some leakage through the cap as there is no breather on the tank and any pressure build up from movement or heat expansion must escape through the neck to cap gasket as the valve in the cap is one way in to prevent a vacuum when the heater is drawing fuel from the tank.
The only solution would be to drill and tap a fitting into the top of the tank and run a breather hose up high with a small fuel filter on the end.
The easier solution might be to never fill it past 1/2 or 2/3rds so that only fumes not fuel are expended.

I put a piece of duct tape around the cap just to stop it loosening a little.

Seems to work.