Rear Drum Brake Question
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- killian96ss
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Rear Drum Brake Question
It's been a while since I have messed with drum brakes and I have what should be a simple question, I think. I am completely overhauling the rear drum brakes on my 88 S10 Blazer and I can't remember how to put the shoes on. On each side you have 2 shoes and one always has more surface area. Does the longer shoe go towards the front or the rear? I think the larger shoe goes toward the front, but like I said it's been a while. I'm only 33 and I feel like I'm having a senior moment.
Steve
Steve
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Re: Rear Drum Brake Question
Ok, I'm having another moment. I think what I said here is wrong and the larger shoe goes on the rear. Anyone care to comment?killian96ss wrote:I think the larger shoe goes toward the front, but like I said it's been a while.
Steve
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I second this.. but never understood why.Jigg wrote:small one goes in the front.
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Thanks! After thinking really hard about it, I started to remember about the primary and secondary shoes and how they apply pressure.daevans315 wrote:I second this.. but never understood why.Jigg wrote:small one goes in the front.
The small primary shoe is actuated first which then applies even more pressure to the larger secondary shoe. I know if you put them on backwards one of the shoes will wear out very quick.
Thanks again for helping me remember.
Steve
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I don't want to assume that Ford's drum brakes are the same as GM's, but if they are you will notice that one of the shoes has a longer lining or more surface area. The pressure applied to each shoe is different which is why one is larger than the other. On GM vehicles the smaller shoe goes towards the front and the larger shoe towards the rear. The smaller shoe or (primary shoe) is actuated first and then it transfers even more force to the larger shoe or (secondary shoe). The difference in force applied to each shoe is the reason why there are 2 different sizes. If you put them on backwards you will overheat one of the shoes and cause it to wear down rapidly. Pull one of the drums of your wifes Taurus and measure each shoe (lining) and see if they are the same or different. On second thought you might want to check both sides just in case you put both larger or smaller shoes on the same side. If they are all the same size you have nothing to worry about. If they are different sizes I would call your local Ford dealer and ask if the smaller shoes go on the front like GM drum brakes.border man wrote:
Please educate this young Jedi, as I have recently replaced the rear shoes and drums on my wifes Taurus. I'm getting a lot of squeak in the rear, and yes I cleaned everything good.
Steve
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Automotive brake shoes consist of a primary and secondary shoe. The primary brake shoe is the front shoe and normally has a slightly shorter lining than the secondary shoe. The secondary shoe is the rear shoe and has the largest lining surface area.
THE PRIMARY SHOE
— is also called the leading shoe
— is the shoe that is toward the front of the vehicle
— when it is forced against the brake drum, friction causes it to shift
slightly in the direction that the drum is turning
— an anchor pin permits only limited movement
— the shifting of the primary shoe forces it against the bottom of the
secondary shoe, which causes the secondary shoe to contact the drum
THE SECONDARY SHOE
— is also called the trailing shoe
— is the shoe that is toward the rear of the vehicle
— makes contact with the brake drum as a result of movement and
pressure from the primary shoe and wheel cylinder piston
— increases the braking action
The linings are of different lengths to equalize the forces and wear evenly. This is part of the reason the brake reacts differently in reverse.
There are systems that use equal length linings. For instance a dual wheel cylinder system, S-cam and wedge brakes are examples.
Last edited by HenryJ on Wed Jun 28, 2006 6:12 pm, edited 2 times in total.
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No first hand knowledge on the Taurus. Most of the stuff I do now is trucks.
Unequal length linings on the shoes is more common on the vehicles that I have seen.
Unequal length linings on the shoes is more common on the vehicles that I have seen.
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Now, I remember what these things were used for that has been in the bottom of my tool box
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There should be one more in your toolbox that looks like a bent prybar for turning the star adjuster.
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You're absolutely right04crewvt wrote:There should be one more in your toolbox that looks like a bent prybar for turning the star adjuster.
Now, I just need to figure out why I have four point craftsman sockets
Whoops, I meant 8 pt sockets
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They are to adjust the bands on your buddies Dodge transmission and change the oil in the lawnmower.f9k9 wrote:...Now, I just need to figure out why I have four point craftsman sockets ...I meant 8 pt sockets ...
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It took me a while to find these same tools buried in my garage.f9k9 wrote:Now, I remember what these things were used for that has been in the bottom of my tool box
I remember having to replace and adjust the drums on all 4 corners on some of my older vehicles.
Thank god for the invention of disc brakes.
Steve
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killian96ss wrote:I also seem to remember how much fun it was to do a panick stop in a vehicle equipped with drums on all 4 corners.
Yeah, those were the fun days.
Steve
See tag line below. 1964 impalla. 4,200 pound car. 4 wheel manual drums. Single chamber master cylinder.
I have been pulling on the steering wheel with my a$$ off the seat trying to get her shut down. When my grandpa had this car in the 70's he towed a lot with it.. I can't imagine.
There is something to be said for 40 year newer brake technology...
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I've been there too, and know what you mean! I used to own two 1968 Impala's. One was a Fastback (drag car) and the other was a Custom (daily cruiser). Both had 4 wheel drum brakes.daevans315 wrote:See tag line below. 1964 impalla. 4,200 pound car. 4 wheel manual drums. Single chamber master cylinder.
Steve
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My first car was a 79 4 door Nova with drum brakes. One of the first things I ever worked on were those brakes.
My 89 full size chevy pickup still has rear drums and when in 4 wheel drive the antilock brake system disengages just when you need it the most.
My 89 full size chevy pickup still has rear drums and when in 4 wheel drive the antilock brake system disengages just when you need it the most.
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Steve
History
Experiments with disc-style brakes began in England in the 1890s; the first ever automobile disc brakes were patented by Frederick William Lanchester in his Birmingham factory in 1902, though it took another half century for his innovation to be widely adopted.
Modern-style disc brakes first appeared on the low-volume Crosley Hotshot in 1949, although they had to be discontinued in 1950 due to design problems[1]. Chrysler's Imperial division also offered a type of disc brake from 1949 through 1953, though in this instance they were enclosed with dual internal-expanding, full-circle pressure plates. Reliable modern disc brakes were developed in the UK by Dunlop and first appeared in 1953 on the Jaguar C-Type racing car. The Citroën DS of 1955, with powered inboard front disc brakes, and the 1956 Triumph TR3 were the first European production cars to feature modern disc brakes[2]. The next American production cars to be fitted with disc brakes were the 1963 Studebaker Avanti[3] and the 1963 Chevrolet Corvette.
From Wickpedia free encyclopedia
Actually:Thank god for the invention of disc brakes.
History
Experiments with disc-style brakes began in England in the 1890s; the first ever automobile disc brakes were patented by Frederick William Lanchester in his Birmingham factory in 1902, though it took another half century for his innovation to be widely adopted.
Modern-style disc brakes first appeared on the low-volume Crosley Hotshot in 1949, although they had to be discontinued in 1950 due to design problems[1]. Chrysler's Imperial division also offered a type of disc brake from 1949 through 1953, though in this instance they were enclosed with dual internal-expanding, full-circle pressure plates. Reliable modern disc brakes were developed in the UK by Dunlop and first appeared in 1953 on the Jaguar C-Type racing car. The Citroën DS of 1955, with powered inboard front disc brakes, and the 1956 Triumph TR3 were the first European production cars to feature modern disc brakes[2]. The next American production cars to be fitted with disc brakes were the 1963 Studebaker Avanti[3] and the 1963 Chevrolet Corvette.
From Wickpedia free encyclopedia
[size=75]Why does the universe decree that if you have all the time in the world to work on projects you have no money and vice versa?
Green 2004 ZR-5 w/ too much to list here: http://www.cardomain.com/ride/2296465[/size]
Green 2004 ZR-5 w/ too much to list here: http://www.cardomain.com/ride/2296465[/size]