I am replacing brake shoes on my '59 Galaxie. The old ones were small shoe on front and large on rear. I ordered new shoes and cylinders from Rock Auto. The rears they sent are all same size (large). I went ahead and installed them but after talking with a old local mechanic he said they should be as the old set was . I ordered in a new set from a local auto supply and they are also all the same size. Is that the way they are supposed to be? It's hard to believe that two sets from two different places are wrong.
Rear Brake Shoes
- Thread starter metro1
- Start date
I've been scanning the other forums today and saw several other posts about people getting all same size shoes. Some came from NAPA and others came from O'Reilly Auto Parts and Rock Auto. One of the post went back to 2014. It seems some of the manufacturers have gone to just making one size shoe. Some people have installed these and had no noticeable negative effects. The front ones I was sent are correct, one small and one large. I'm going to return the recently purchased rear shoes and look around to see if I can find the correct ones.
V8COOPMAN
Well-known member
What SOME of y'all MAY NOT understand is the basic concept of how a "Bendix" (Duo-servo) brake works.
Duo-servo Bendix-style brakes are easy to identify. They have a single, fixed anchor pin at the top of the backing plate with a dual-piston wheel cylinder mounted below the anchor. A threaded, star wheel adjuster links the lower ends of the shoes. Earlier applications required periodic, manual adjustment of the shoe-to-drum clearance. By the '60s, self-adjuster mechanisms became popular on cars and light trucks.
How Bendix Duo-Servo Brakes Work
When the driver applies brake pedal pressure at the master cylinder, fluid disperses to each wheel cylinder. The curved top ends of each shoe fit against the round anchor pin. As the pistons move outward in the wheel cylinder, the shoe lining contacts the drum. The linked shoes attempt to rotate with the drum. With the vehicle traveling forward, the rear shoe stops against the anchor pin. Backing up, the front shoe stops against the anchor pin.
The obstructed rotational force now redirects, pressing the shoes outward against the drum. This additional force, referred to as "self-energizing", is beyond driver input and hydraulic pressure. When self-energizing force can apply in either direction of rotation, the system is called duo-servo.
As the vehicle moves forward, the self-energizing force is greater at the rear shoe. To keep lining wear even, the rear shoe's lining is longer and sometimes of different composition than the forward shoe. With a shorter lining on the primary or forward-facing shoe, self-energizing force is slightly less when the vehicle moves backward. Since the vehicle does not back up at high speeds, braking is sufficient in either direction. In other words, during normal FORWARD rotation, the LONG (rear) shoe actually does MOST of the braking.
So, in all likelihood, most manufacturers today probably feel that it costs less to manufacture ALL shoes in one flavor (with LONG linings), than to set-up an additional line to manufacture a shoe with a different, SHORTER-length lining.
Back in the day, Henry and other high-quantity manufacturers wouldn't hear of "wasting" that extra inch of lining.
Coop/AMERICAN
.
KULTULZ
Well-known member
OK ...
Here is what you may want to look at -
They are first quality riveted shoes. Easiest way out without having your shoes relined (IMO).
Bake and Steering/Suspension are two areas you don't go into a BOX STORE to buy.
NOTE : Verify Correct Application and PN Before Buying -
Here is what you may want to look at -
- RAYBESTOS ELEMENT3 PREMIUM 55PG
They are first quality riveted shoes. Easiest way out without having your shoes relined (IMO).
Bake and Steering/Suspension are two areas you don't go into a BOX STORE to buy.
NOTE : Verify Correct Application and PN Before Buying -
Attachments
Last edited:
KULTULZ
Well-known member
KULTULZ
Well-known member
And if you actually read period BRAKE SHOW SPECIFICATION CHARTS, you will see different length linings had an additional purpose.
- 1957 FORD BRAKE SHOE SIZING CHART -
Look at the below chart. There is given the other reason for lining material length -
Oh well, just might as well use them as they will go great with the ever popular CHI-COM CARB and CHI-COM GM HEI STYLE DIST.
SIMILAR THREAD - https://www.fordbarn.com/forum/showthread.php?t=313498
Attachments
Last edited:
58Yeoman
Senior Member
Why would you want to grind the new ones down to match the worn shoes ...
Length of lining, not thickness.
KULTULZ
Well-known member
rotorwrench
Well-known member
The primary shoe has to move a bit more that the secondary so they reduced the lengths of the lining to allow for that movement. I'd be more concerned about the rear brake cylinder inner diameters. They were smaller bore to allow for less brake action. Cars didn't have proportioning valves yet so most of the braking action comes from the front end. That chart shows the bore sizes.
58Yeoman
Senior Member
Attachments
KULTULZ
Well-known member
Strike 3 on these brakes!!! The front shoes I received from RockAuto a while back were Bosch and they are correct. Small shoe for front and longer and thicker shoe for back. After getting 2 other brands for the rear, which were both wrong, I figured since Bosch had the correct front ones they would have correct ones for the rear. Just received those today and just like the others all shoes are long. I give up! Now to decide whether to trim the lining to make shorter front shoes or install what was sent. Trimming them would be easy enough so I might go that route.