Leaking fuel pump




Would you be comfortable drilling your tank rim at low speed to insert a better machine screw?
There are 6 screws normally in use, perhaps you can leave with one missing if Indeed the tank seal does not done need pressure to seal (finger tight nuts).
Last edited by CaliBenzDriver; Mar 1, 2022 at 10:17 AM.




k, looked up a random 212.056, which is a early (M272) E350 sedan, it too has a bayonet locking ring holding the fuel pump assemblies in place, the aux pump on the right, and the main pump on the left.
oh wait, no, the earlier style sedan shows 12 total 'nut and washer assemblies' (6 per side?), and those have a note: OBSERVE WORK INSTRUCTIONS IN WIS AP47.00-P-4750-TZV ...
no studs are shown, leading me to believe they are part of the gas tank assembly.
ok, let me dig out that WIS page.... this is always a fun adventure, I have to fire up a VM, and sometimes it works, other times it crashes.
ok, AP47.00-P-4750-TZV is completely useless, its all about how you purge the tank before working on it, then pressure test for fuel leaks after.
gahhh, as is too common with WIS, I'm lost in a sea of useless information. I'm guessing those nuts should have /very/ small torque on them
Last edited by Left Coast Geek; Mar 1, 2022 at 04:53 AM.
Having said that.. I would give a rivnut and bolt a try in place of the defective stud.
Drain the tank first. Maybe run some compressed air inside to dry it out before any drilling takes place.
May have to use a tiny oring around the bolt to seal the threads.



