brake reservoir cap rubber

Bill, please verify it is the correct one for your application. It was the correct one for my 77 W200 and I believe it will be the correct one for yours as well since I compared my 73 disk brake MC to my truck MC and it appeared to be the same. It is a Dorman 42069. You may want to try your local auto parts store first as they may have it in their help section, but I doubt it. If not, they may be able to get it for you next day if they have it in their warehouse. If neither of those options work, Summit Racing has it; that's where I got mine.