Primer Pump
 

Hi:
After I changed my fuel filters I unscrewed the hand pump to prime the system. As I pumped it, fuel leaked out all over the place. It doesn't seem to leak when screwed in. Can I just replace the primer pump (~$15 on this site) to fix the leak when pumping?
Note for Peter, I changed my thermostat and now run a steady 80C. In stop and go for extended periods it got to 90. Thanks for the advice. I also found a not-tight-enough clamp on the input to my in-line fuel filter, it was sucking a little air I think. I think I run smoother now that it is tight.

Thanks much.

just replaced mine this morning
 

Yes, the new ones are way better; you don't have to unscrew the knob... I was able to remove the old one with vice grips and had just enough room to tighten the new one with a 17mm open end wrench. By they way, my old leaky hand pump allowed air into the fuel system causing rough idle and poor performance.

dzldog:
Thanks for the info. I saw your earlier thread about changing the hand pump and it prompted my question. I might be sucking air also which I hear could cause a rough idle. I hope the part comes in today so I can change it this weekend. We have had unbelievably nice weather for the past 2 months here in Colorado but, it can't last.

Later,
MikeyOh

I got a bath in diesel fuel the first time I tried to prime my 220D -- priming pump was shot. Sucked the fuel out of the tank fine, but sprayed it all over me when I pushed down, rather than into the fuel filter! I ended up buying a set of crow-foot wrenches to get the old one off and the new one on.

The mew pump is so much nicer!

I had to put a new thermostat in the 300D when it cooled off here, too -- barely 40 C at 0 C outside! Climate control runs cold anyway, so I was freezing! Quite an experience as I'd not changed one on a 603 before -- it's in the lower rad hose connection on the block, and almost unreachable until you take the inlet hose off the turbo -- I still took out two bolts I didn't need to!

Peter

lucky guys!
 

Look at it this way...at least you got the right pump! I have to wait ( and leak fuel) for the whole weekend while I wait for the "Bin" to open on Monday:eek: I called and ordered my pump on Thurs. and had it next day delivered, only to get the wrong pump. I don't know how I could better describe to them what I need, unless someone has the CORRECT part # for a '76 300D primer pump. I gave the guy my VIN#, year and model. Then told him it was a"saucer shaped" pump NOT a cylinder (tube) shape. MY pump goes on the filter housing NOT on the I/P and it has a fuel line that connects to it, whereas the "new" style does NOT. I even questioned him when he told me what the part # was , because I was given a different PN from the MB dealer in Grand Rapids. ( I was given a "different" price too as you all might imagine!) Does anyone know if the style pump I need is still available? I don't find a listing for anything other than the "new" and improved Bosch # on the Benz-Bin page. Other than this little "inconvenience" I think the old girl is going to work out pretty good! She is still an eyesore to look at , but after a tune up, valve adjustment, and two tanks of biodiesel and two tanks of "treated" soydiesel this this REEEAALY runs sweet!