When I remove the fuel tank cap on my 1985 300SD, a blast of compressed air
escapes/ or possibly it is a vacuum rushing in, I can't tell.
I just replaced the leaking fuel line from the strainer, so possibly
the pressure/vacuum was previously venting via the leak.
The new fuel line does not leak, and I now have this pressure/vacuum in the tank.
There must be a vent somewhere, but I looked at the cap and can't see any
vent hole in it.
Is there separate vent plumbing, where is it?
Can it be cleaned out or do I replace it?