Bill, The bellows mechanism is the power brake vacuum booster and the tank is the vacuum reservoir. These remain in the system. If there are any cracks in the bellows or if that component has not been gone over, I suggest that you remove it and send it to Karps rebuilders in CA. A hole in the bellows will put you into manual mode of braking and believe me it is no fun. ROB KERN ----- Original Message ----- From: Bill Leahy Cc: Chrysler300@xxxxxxxxxxxxxxx Sent: Tuesday, July 08, 2008 8:50 PM Subject: [Chrysler300] to do disk brake conversion or not RE: 1957 conversion to disk brakes the overwhelming consensis from the 300 club is to do the disk brake conversion from AAJ brakes. so, i'm looking at the old master cylinder in my car and that accordian looking jobbie setting squarely on top of it... and i assume the new master cylinder fits in there with a struggle (but some how fits, right). what the heck is that accordian looking jobbie in the first place / do i get to get rid of it or does it have to stay? then there's that tank gizmo right next to it...what the heck is that? and can i get rid of that? do i get to use the existing brake lines if i just do the front brakes? i sent a message to the AAJ people yesterday but did not get an answer yet. hopefully they will shed a little light on this subject. billllllllll in kennewick washington (still hot hot) i did not hear from anyone saying not to do the conversion / please speak up if it did not work out for you. [Non-text portions of this message have been removed] ------------------------------------ To send a message to this group, send an email to: Chrysler300@xxxxxxxxxxxxxxx For list server instructions, go to http://www.chrysler300club.com/yahoolist/inst.htm For archives go to http://www.forwardlook.net/300-archive/Yahoo! 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: mailto:Chrysler300-digest@xxxxxxxxxxxxxxx mailto: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/