Tom and All: The 300D, or any other lettercar did not originally have a "plastic bottle reservoir" above the master cylinder. As you suggest, the fluid level, if maintained a little below the top edge of the master cylinder, reservoir would be just fine. I have no idea why the additional reservoir is there. The original seal was not rubber, but a disk made from a "cardboard" like material. (I am sure some member can come up with the correct material de scription.) It of course, had a hole in the center so the cover retaining bolt could pass through. That bolt, in turn, had a little metal "gasket" washer to seal the bolt head to the M/C cover. The cover to M/C body seal was just to prevent spillage due to splash. Hope this helps a little. 300ly, Gil Cunningham In a message dated 3/1/2011 5:49:09 P.M. Eastern Standard Time, tchvapil@xxxxxxxxxxxxx writes: Hi everyone, I need little advice regarding the rubber 'seal' on the master cylinder cover. The one on the car started to leak and is in pretty bad shape. Looks like it was a molded rubber seal with the outer edge raised? (Or did this happen over the last hundred years it was on the car? Anyhow, I have tried several materials and everything starts leaking after a few days. I don't know if all Ds had the plastic bottle reservoir above the master, but that is definitely the culprit. If I kept the brake fluid level just a bit below the top of the master cylinder, it would be OK.... Does anybody sell the gasket (seal) for this application, or is there a different way of attacking this? Thanks a bunch, Tom PS Quick update on rest of the car: Parking brake is fixed and now works better than the power drums... Headliner (from Gary Goers) is in and looks great rear panels and armrests were completely redone by a local shop and I just finished putting them in front door panels are done, but we are still working on the window motors and finishing the cat whisker installation all around, so I haven't put them in yet Tom Chvapil Tucson,Az tchvapil@xxxxxxxxxxxxx ------------------------------------ To send a message to this group, send an email to: Chrysler300@xxxxxxxxxxxxxxx To unsubscribe from this group, send an email to bob@xxxxxxxxxxxxx or go to http://autos.groups.yahoo.com/group/Chrysler300/join and select the "Leave Group" button For list server instructions, go to http://www.chrysler300club.com/yahoolist/inst.htm For archives go to http://www.forwardlook.net/300-archive/search.htm#querylangYahoo! Groups Links [Non-text portions of this message have been removed] ------------------------------------ To send a message to this group, send an email to: Chrysler300@xxxxxxxxxxxxxxx To unsubscribe from this group, send an email to bob@xxxxxxxxxxxxx or go to http://autos.groups.yahoo.com/group/Chrysler300/join and select the "Leave Group" button For list server instructions, go to http://www.chrysler300club.com/yahoolist/inst.htm For archives go to http://www.forwardlook.net/300-archive/search.htm#querylangYahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Chrysler300/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/Chrysler300/join (Yahoo! ID required) <*> To change settings via email: Chrysler300-digest@xxxxxxxxxxxxxxx Chrysler300-fullfeatured@xxxxxxxxxxxxxxx <*> To unsubscribe from this group, send an email to: Chrysler300-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/