k got a housing that has a very small knick on the very very edge of the housing. Is it possible to reuse a housing like this by just machineing down that one small edge?

 

Since there are very few autoviewers on the forum anymore, (the government kidnapped all of them ), post a pic.

 

Nick, as in something struck the corner of the housing and pushed the compression surface up and in a little?

If it's less than 1mm in size you should be okay. Just take a fine half round file and gently work it down, no need for machining. Perhaps even a dremel on low speed with a high grit sandroll would work also, then use a polishing bit to bring it back smooth. It's better to take off a hair too much material and leave a low spot and lose a little sealing for a millisecond, than leave a hair too much material and leave a high spot that will interfere with the seal and cause an odd wear pattern on it.