In addition to this situation, I also remember that when installing "new" shoes, that on the raised areas of the backing plate, where the brake shoe contacts, that a "small" quantity of "lubriplate" grease be applied to those areas to "prevent" the hang-up of the brake shoe and to aid in the complete return of the shoes to the adjustment excentric. Also, when changing shoes, make sure that those "raised" areas are clean and "bright" with no dust, dirt or friction material residue. George ----- Original Message ----- From: George Riehl To: Chrysler300 list ; Bob Merritt Sent: Wednesday, April 08, 2009 12:50 AM Subject: Re: [Chrysler300] Center Plane Brakes Wow! This brings back a memory! Some years ago, when Chrysler sent me a whole bunch of info on the 300s, there was a Service Bulletin about "squeaking brakes" concerning the "center plane system". When all else failed to solve the problem, it was suggested that the mechanic take a hacksaw and install two blades. Then make a somewhat small cut (approx. 1/16" deep) from the toe to the heel of the lining diagnally top left to bottom right. Years ago, I did have this problem on my F. The "springs" were on the drums but still "squeeked". I pulled off the shoes and installed two blades on the hacksaw and made the cuts. Put everything back togeather, never a sound from then on. Why did it work? Your guess is as good as mine. George Riehl ----- Original Message ----- From: Bob Merritt To: Chrysler300 list Sent: Tuesday, March 24, 2009 1:57 PM Subject: [Chrysler300] Center Plane Brakes This message was on another list but might be of interest. ----- Original Message ----- From: "Burton Bouwkamp" Subject: [Imperial-Club] CENTERPLANE BRAKES From 1954 to 1960 I was a product engineer (called "resident engineer") at the Chrysler Jefferson Plant. During that time Chrysler came out with centerplane brakes. It was a great concept on paper - the shoe web floated between two aligning plates and the friction material aligned itself with the drum on application. I think the merchandizing name was "Total Contact Brakes". Center plane brakes worked fine as brakes - but they were noisy! Brake squeak!!! We tried lots of different linings but it didn't help. (Although, it did give us an answer for top management. When they asked why the brakes squeaked on their personal car we answered, "you don't have the latest lining"). Finally - in desperation - we added raised plateaus to the backing plate to touch the side of the brake shoe. The idea was for the shoe/backing plate contact to work like putting your finger on the side of a vibrating tuning fork. The problem was that in production the dimensional variations in the brake were so great that on some cars this fix worked as intended and sometimes it resulted in dimensional interference that caused shoe returnability problems and/or shoes that would not align themselves with the brake drum unless something deflected - obviously compromising the "total contact" concept. We fought this problem for years - and finally gave up trying to make the centerplane brake concept work. We decided to join the rest of the industry in using the "Lockheed" brake design. Burt Bouwkamp [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 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/