Reg Evans Posted January 30, 2007 Report Posted January 30, 2007 I'm doing a complete brake job on the 40 Plymouth and was surprised to see that the right rear shoes are installed with the short shoe forward and on the other three sides the short shoe is in the rear. Which is correct? Here's the right front. Quote
40phil41 Posted January 30, 2007 Report Posted January 30, 2007 A while ago Frank McMullen posted the correct brake lining installation for many years of MOPARs. This is what he stated for pre-war MOPARS having one wheel cylinder per wheel "the primary shoe (front shoe) has a full length lining. The secondary shoe (rear shoe) has a short lining". This is how I installed mine and they appear to be working as intended. Hope this helps. Phil Ellis Quote
Reg Evans Posted January 30, 2007 Author Report Posted January 30, 2007 Thanks Phil ! That's what I thought but wanted to make sure. For some reason the rt. rear. on the car had them reversed and the rest were like the photo. Quote
captden29 Posted January 30, 2007 Report Posted January 30, 2007 are there any hydraulic brake systems simpler than this [ except for pulling the drums]? dennis Quote
bob westphal Posted January 30, 2007 Report Posted January 30, 2007 As best I can remember, every car that I have replaced brake shoes on has the short shoe in the front. The '66 Ambassidor that I did yesterday did. Interestingly, my Plymouth shop manual shows that the front axle has both shoes of the same length & the rear has the short shoe on the rear. Quote
40phil41 Posted January 30, 2007 Report Posted January 30, 2007 Bob, We were talking about pre-war MOPARS above. If you go back to Frank's original post (Sept. 20, 2005), "the post-war MOPARS with the new 2-cylinder front brakes and single-cylinder rear brakes had: Front brakes - both shoes have a full length lining, since both shoes function as primary shoes. Rear brakes - primary shoes (front shoes) have a full length lining whereas the secondary shoes (rear shoes) have a short lining, starting at the top of the secondary shoe (this is opposite of the pre-war short-lining shoes)." Frank, hope you don't mind me quoting you? Phil Quote
grey beard Posted January 31, 2007 Report Posted January 31, 2007 MoPar drum brakes that have two cylinders per wheel do not really are which lining is where, since there is no interaction between primary and secondary shoes possible - each shoe is pinned to its own backing plate. It is with those brakes that use one wheel cylinder only per wheel where primary and secondary lining may be of importance and brake shoe interaction may be possible. The new shoes and lining I just installed on my own B1B came with all the same size lining on every shoe - front and back. Go figure . . . . . . JMHO:) Quote
Frank M. Posted February 2, 2007 Report Posted February 2, 2007 Hi Reg. Reason for the shorter lining on the back is that the forward rotation of the wheel fights the back shoe. Quite the opposite, the front shoe is actually helped in comming out by the wheel rotation. This is why Chrysler Corp. engineers went to two separate cylinders on the front wheels. The rotation helps the "toe" of the shoe when applied. They called this " self energizing brakes" All rear shoes back to 40 had shorter lining. This gave the rear piston of the wheel cylinder more leverage. Also- if you note-the rear piston was a bigger diameter. They were trying a lot of methods to increase braking power. Greatest-in my estimation -was the change to two cylinders in the front. Just my shot at it. hope it helps Frank M Quote
Reg Evans Posted February 2, 2007 Author Report Posted February 2, 2007 Thanks for all the helpful information guys. My shoes are ready to be picked up from having them relined and hopefull I can put them all back together this weekend. My wheel cylinders are a little pitted but I'm going to go against my better judgement on this one and hone them out. The man that turned my brake drums says they were virgins....never turned before! Havent had any of those for a long long time. Quote
De Soto Frank Posted February 2, 2007 Report Posted February 2, 2007 Hi Reg, Yes, us pre-war guys, with the Stepped-Bore wheel cyls are supposed to put the short lining on facing the rear of the car. All this "short-lining" / "long-lining" / stepped-bore wheel cyls etc. was the result of Lockheed/MoPar engineers trying to achieve their "ideal" brake bias with the fixed-anchor system. They kind of "standardized" on a design when they went to the single-piston front brakes from '46-'56, and used full-legnth linings on both shoes for the front wheels ( since both were essentially "leading shoes", and were "self-energizin" when the car was moving forward), and eventually wound-up using full-legnth linings for both shoes in the rear drums as well. As they moved on to the "floating" shoes with the '57-'59 "Center-Plane" and '60-'62 "Total Contact" brakes, I believe they used full-legnth linings all the way around. If your old wheel cyls don't clean-up to your satisfaction, I believe Roberts has replacements for about $50 each... certainly not "Bow-tie cheap", but a lot cheaper than having to have two sleeves put-in.... Good luck ! Frank McMullen Quote
Merle Coggins Posted February 2, 2007 Report Posted February 2, 2007 What's been a bit puzzling to me is that the truck brakes are reversed from the cars. On a truck the single, stepped, cylinder brakes are at the front, whereas the dual cylinder brakes are at the rear. Assuming the dual cylinder brakes afford more stopping power, it makes sense to have them up front. So why are they at the rear on the trucks? Are they figuring that when loaded the higher stopping power will be needed out back? But what about when running around empty? Now my greater braking is done at the light end of the truck. And regardless of load, when braking the weight transfers forward putting more of the weight over the front axle. Just a thought that's been rattling around in my head since I did my brakes. Merle Quote
Reg Evans Posted February 11, 2007 Author Report Posted February 11, 2007 I sent my brake shoes out to be relined. (4) long shoes and (4) short shoes. They came back all long. Is this gonna cause a problem? I hate problems. This brake job isn't going as smoothly as the others I have done....mostly thanks to Mr. A Bermbaum's junk. Quote
De Soto Frank Posted February 11, 2007 Report Posted February 11, 2007 Reg, Don't know if it will be a "problem"... if you've got the Ammco gauge or reasonable facsimile to "dial-in" the anchor pin settings, it'll probably be acceptable. Another thing to check is the thickness of the linings your jobber used: our brakes are supposed to have a 13/64" thick lining, which is a shade over 3/16" thick; sometimes they come back with 1/4" thick linings, which have to be ground-down to match the curvature of the drum ( using your trusty Ammco brake shoe grinder)... I have a set of shoes to send-out this spring; I am going to include very specific instructions and photocopies of the images from the shop manual, and hopefully the jobber will accomodate; trouble is, nowadays, Bendix-type self-energizing brakes have been about the only drum design in use for over 40 years, so they think that all brake shoes should get relined the same (Bendix) way... I got a set of relined shoes from Bernbaum eight years ago... I don't recall if they were lined "per factory" or long linings on both... Hope yours work-out ! Frank McMullen Quote
Reg Evans Posted February 12, 2007 Author Report Posted February 12, 2007 Thanks for the info. DeSoto Frank McMullen ! Quote
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