Thanks Don. I found the old receipt from NAPA for the last time I rebuilt it, in 1997. The part# is 191, so the listing on our NAPA parts list is only for manual brakes, not power. NAPA confirmed the kit was a 1-1/8" diameter, I ordered one from them, although he indicated to me it was existing inventory and slated to be discontinued. Bob J From: Chrysler300@xxxxxxxxxxxxxxx [mailto:Chrysler300@xxxxxxxxxxxxxxx] On Behalf Of Don Verity Sent: Monday, October 31, 2011 2:27 PM To: Chrysler300@xxxxxxxxxxxxxxx; Bob Jasinski Subject: Re: [Chrysler300] '61 300G master cylinder kit Hi Bob, The master should be 1 1/8. They didn't go to 1 inch until 63 with the bendix brakes. NAPA's listings are not always accurate. The rubber boot is a dust boot, and is not there to stop leaks. As you have found out, the master is leaking. Best to fix it now before it becomes a problem. Don Verity ----- Original Message ----- From: Bob Jasinski To: Chrysler300@xxxxxxxxxxxxxxx <mailto:Chrysler300%40yahoogroups.com> Sent: Monday, October 31, 2011 4:47 PM Subject: [Chrysler300] '61 300G master cylinder kit I noticed a strange thing happening with my master cylinder. The rubber boot on the pedal side of the master is torn and leaks occasionally. The brakes are working fine, but I'm sure the best thing to do is remove and rebuild the cylinder with new rubber parts, as the boot is included in the rebuild kit. Here is my question. NAPA still has availability of the kits, but they show two different sizes for the 300G with power brakes, a 1" and a 1-1/8" bore. I had not heard of this before and asked him if he was confusing it with manual brakes, and he said no, that is yet another kit, #319 (which is on our website as being available through NAPA). So....without taking the thing apart first, does anyone know if it should be a 1" or 1-1/8" cup? Why would there be two sizes? Even the factory parts book only shows one for the application. Bob J [Non-text portions of this message have been removed] [Non-text portions of this message have been removed] [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/