Author Topic: Tank breather/vent system  (Read 73 times)

Jan S

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  • W116 Enthusiast
  • Location: Norway
Tank breather/vent system
« on: 24 January 2021, 09:05 AM »
The car is a 1975 W116 450 SE US-version.

Today I replaced the two hoses going into the tank - the left pipe is the return line from FD, the right pipe is the breather (see pic).

In the parts diagram (see pic) the breather pipe is connected at the top of the tank. In my case both return and breather are at the bottom. A detail to forget? Or am I missing something here?

I'm trying to understand how this vent system works. I believe the valve (part 92 in pic) shall maintain a small vacuum in the tank, independent of fuel level in tank. Where is the air going to through pipe 204?

Some tips are appreciated.
1975-mod W116 450 SE with 6.9 engine