Hello averyone, this is my first post to the forum even tho I have been lurking for almost a year now.
Anyway I have just replaced the primer pump on my 1980 300SD.

Twice,
soon to be three times.

I replaced an old style white knob with one of the new bosch models and the thing started spraying fuel all over the place, 2nd one same thing and the third one won't be in till thursday.

So my question is:
Is anyone else having problems with these primers lately?
Am I doing something wrong?

I am certain the fuel is not coming from around the copper crush washer, it is coming from under the black plastic cap/plunger.

I am considering priming the system and quickly plugging the whole for the primer and hoping that I never develop an air leak.

Any thoughts or comments?