Operating wedge

[Richard Knight]

I bought a pair of new front brake operating wedges from a local vendor. They came in the typical plastic baggy with the Ford authorized propaganda on it but nothing about the source which I suspect is either Snyder's or brattons. Can anybody comment on the use of the part? Use as is, modify, or not use. Thanks.

 

[Richard Knight]

I tried to upload two photos but that didn't seem to work!

 

[Joe K]

As in below?

Various image types "don't copy over" depending on the variant of the board software. Generally anything ending in "jpg" SHOULD copy.

Joe K

 

[Richard Knight]

Joe, thanks, yes. I have compared it to the print that Jim Mason posted and it looks similar. I am wondering who is using them also.

 

[JayJay]

I don’t believe that Brattons is authorized to use the Ford logo, that’s why the part numbers in the Brattons catalogue don’t match Ford numbers. Most if not all of the “official” Ford packaged parts I’ve purchased have come from Snyder’s, who supplies other vendors as well.

I would inspect for burrs but otherwise use them as they are.

 

[Richard Knight]

Jay Jay, thank you. There are a few little areas that I think need some file work.

 

[Jim Mason]

If the part is properly hardened it will be problematic to file.

 

[nkaminar]

I have often wondered why there are two sets of ramps. Does anyone know?

 

[Sunny the Model A]

I have often wondered why there are two sets of ramps. Does anyone know?

My theory is that the reason for the dual ramps is twofold, to spread the pressure out to multiple rollers to help prevent wear and to also prevent the shoes from twisting when pressure is applied.

 

[nkaminar]

Each side has a bump and slightly different slopes before and after the bumps. Why?

 

[Sunny the Model A]

Each side has a bump and slightly different slopes before and after the bumps. Why?

well, the bumps are the resting position, when the brakes are not being applied the shoes are fully retracted, and since the rear brakes apply first in a steady application of pressure, the first part of the wedge above the step is to get the shoes up against the drum, the rest of the slope is to slowly increase the pressure. the rear brakes provide 60% of the braking force, as such the fronts are designed to provide a heavy drag but not to lock in a panic stop so the car can still steer around obstacles. the design of the brake system of being able to steer under braking saved my rear end a few times in traffic.

 

[CWPASADENA]

At rest, the rollers are on the steeper part of the ramp. During initial brake application, this steeper part of the ramp quickly moves the bottom of the shoes out taking up the clearance between the linings and the drums. As the brake pedal is further depressed, the rollers will move up the ramp and onto the angle that is shallower. This shallower part of the ramp allows for more mechanical advantage which results in greater braking force.

If the wedge was designed a ramp with only the steeper angle, it would take a lot more pedal effort to stop the car.

If the wedge was designed with a ramp with only the shallow angle, it would take a lot more pedal travel before the brakes applied. In this case, you may run out of pedal travel before heavy braking is achieved, as with a panic stop.

This is why it is important, when using oversize drums, to use thicker linings so at rest, the rollers are positioned on the lower, steeper part of the ramp. If you do not use thicker linings, the rollers may be positioned on the upper or shallower part of the ramp. In this case, you may run out of pedal travel before the brakes are heavily applied as during a panic stop.

Chris W.