Fuel Pump

[cml55]

I did a search and I could not find an answer.  My SL has the long type fuel pump.  It started to leak fuel near the pump.  I changed the two fuel lines as they were rotten, but the leak was still there.  I took the 'cage' off the pump and ran the car.  Fuel is leaking out of a small line which looks like a vent line.  When I changed the fuel lines there was nothing on this line.  Is this a vent line and is there supposed to be a line attached to it?
If the issue is with the pump is there someone that can repair this style pump or is there a replacement pump that will work.
Thanks

[Tomnistuff]

Rebuild kits for the long (and short) pumps are available from Authentic Classics and probably a lot of others, like Mercedes Source.
Mercedes Source also has a detailed video to show how to use the kit to rebuild a leaking pump (a different kit and video for each pump).  I think the video is $9.95 which allows you to watch it as many times as you want, since access to it goes in your member account.
I've bought a short pump kit for my car from Authentic Classics and video for the same pump from Mercedes Source.  I watched the video but I haven't tried the repair job yet.  It looks easy and is very detailed.
NOTE:  The kits are only rebuild kits to fix leaking pumps.  Many internal parts that could be damaged are not available separately anywhere, from what I hear.
Good Luck
Tom Kizer

[Travis71280]

Could someone else confirm this, but I think that is the bypass line from the pump that should tee into the return line going back to the fuel tank.

[ja17]

Travis.  if you use a by-pass, then you must have the return fitting on the injection pump with no hole. With no by-pass use a return fitting with a hole. Research it in the BBB if you have one.

[rgafitanu@gmail.com]

Wouldn't this be the spout vent as described in the technical manual section? This is supposed to release any occasional leak above the bottom bearing and to prevent flooding the motor with gas. I got a donor pump that was leaking there no matter what I tried.
Anyway if you go to the technical section you will find very detailed instructions on how to dismantle the pump and rebuild it. Your bellow seal is not sealing and allowing gas in the chamber above where the vent is. It could be the small 5 mm O-ring or the bellow seal. If you are lucky it's not the bellow seal. If you want I can mail you a set of O-rings (I have a lot).

[450sl]

an alternative at approx 80 euros.