I have replaced the seal on the stop lever probably 4 times over the last years, it leaks oil from time to time. I'm wondering if I got some low quality seals previously or maybe I've been using the wrong seal altogether.

Which seal number is the correct seal?

Thanks,

1991 300d, 218k

On my w124 I used one of the fuel filter o rings , cannot remember if it was the big or small one but it is the correct size seal to use.

the 8mm x 2.0mm O-ring that is usually recommended and shown in writeups did not work for me, too small OD and still leaked. I used a 7mm x 2.5mm and worked perfectly. The thickness is more important than the diameter, you can always stretch a smaller O-ring slightly.

__________________
Current stable:
1995 E320 149K (Nancy)
1983 500SL 120K (SLoL)

Black Sheep:
1985 524TD 167K (TotalDumpster™)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)