Dip stick O-ring

[Frank Smidler]

I just recieved a new 11.75" oil fill tube made of plastic and a new dip stick for my Lyc O-360. The dip stick did not come with an O-ring. When I put the O-ring on from the old dip stick it had a tendancy to squeeze out the side. Is this just a problem on the newer plastic fill tubes? Do you even need an O-ring with the plastic fill tube?

Thanks for your input.