The primer pump is a screw type, slightly different than my SD but both screw types. This primer does not feel like it even pumps any fuel. On my SD you can feel the fuel being pumped, even if it leaks out the bottom of the pump.

So is the only way to test the primer to replace it?

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08 R320 CDI current

Past
95 E420
87 300D Turbo 5spd
90 300TE
83 300SD
85 300TD
92 400E
85 190D