Replace the fuel pump primer
 

Just thought I'd pass on some info:
REcently acquired 300TD that I put a salvage motor in. Noticed that the clear fuel filter was always empty after sitting a while and it leaked when priming the system. Car also started hard.
I replaced the primer with the new Bosch unit that you just push.(under $20). Well the car starts instantly now and the filter is always full. What the problem was, was an air leak. THe worst thing for a diesel. The leak would allow the fuel to drain back and it was the same as starting a car that ran out of fuel. Also now you don't have diesel flooding the motor when you prime after filter change etc.
Do yourself a favor and replace yours NOW! ALso replace the rubber fuel lines for the supply. That rubber is 20 years old!

The easiest way I found to replacethe primer is to totally remove the fuel inlet nipple on the lift pump with a socket. Then you can get an end wrench in there to remove primer unit. If you have the "crows foot" end wrench set then you are good to just remove the primer. HTH MIke Moran

clarirication
 

On the above post I meant the primer unit leaked when priming not the fuel filter.

where did you get it from? is it considered an upgrade or a replacement?

Jen, does Lil Pete still have the old style primer pump with the screw-down handle? If so, Fastlane carries the replacement part.

yep. i unscrew it then pump. is the replacement hard to put in?