Terry, and list, 1. I have two 300-K's. Both have the Midland Ross booster, but one is from an early version that would supposedly not appear on '64 car. 2. When I tried replacing a bad booster and mastercylinder, I too got one from a parts place--Car Quest. The replacment master cylinder also had the lower port with pipeplug fitting. Casting was the same. Worked OK for me. However, I had all sorts of problems with the booster. Long story short--after five replacements, each with a different problem--I sent the old booster to be rebuilt by "Booster" Dewey in OR. Still have the last "reconditioned" booster from Car Quest--ought to send it off to have a working spare at least. 3. I was told by the man behind the counter the second port was because later version master cylinders were used as a core and rebuilt to original specs for the '64. The later version used a split system. I do not know how much later, but my '68 Chry. New Yorker master cylinder looks entirely different, so would be at most from '65 to '67. 4. I am sure this too only muddies the water further. I'd screw in the acorn nut on the end of the pushrod a little and see what happens to braking response and release of the fluid pressure when you let off the brake pedal. Tim ----- Original Message ----- From: Terry Town <terrytown@xxxx> To: 300 List Posts <Chrysler300@xxxxxxxxxxxxxxx> Sent: Tuesday, May 20, 2003 3:44 PM Subject: [Chrysler300] '64 Brake MC/Booster Question > I'm confused and hoping someone can help me out. I have a '64 300 Sport with a 383 and power brakes. I need a new brake master cylinder, so the local NAPA sells me one. NAPA part # 10-36706, it looks very similar to the existing one, but has an additional downward pointing outlet just under the regular horizontally pointing outlet. The second outlet is capped off with a plug, so I figure that the unit will still work fine. When I got the old master cylinder off I compared the two. The NAPA one has a casting number on the bottom of the unit of 2265634. My old one has a casting # of 2265633. Hmmmm. I then noticed that the receptacle depths for the pushrod in the back of the MC piston are different between the two MCs. The NAPA one is about .95" deep and my old one is 1.25" deep. I thought that maybe it's as simple as adjusting my pushrod shorter, so it doesn't stick out as much from the power booster unit. I looked in the factory service manual for adjustment info and here is where I got really confused. My power booster visually appears to be a Bendix Dual Diaphragm type, and the FSM clearly states that these are for Imperials only. (It also says to NOT adjust the pushrod) > > Did 300 Sports come with the Bendix dual diaphragm unit? If so, does anybody know a NAPA part # for the proper MC to use with this booster unit? Or do I need to just adjust the pushrod in about .3"? > > If the booster unit isn't the proper one for the car, I'd like to replace it with the proper one. Any thoughts on where these might be available, part numbers (NAPA or otherwise) to ask for, etc. > > Any help from the group would be appreciated. > > Thanks, > Terry Lynch > St. Petersburg, FL > > [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 > > 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/ > > >