front brake wedge information

[Bob Johnson]

I am trying to make some animations of the front brake system. I have measured the movement using a front wedge that is worn. I would like to have the dimensions of a NOS Ford wedge. Below is a picture of the wedge that Brattons sells. I have estimated the measurement of that wedge but I am not sure of the exact numbers. Also, Bratton's is a reproduction and may not have the same dimentions as an original. I have marked the measurements I would like to have. Also it would be useful to get a picture of an original.

Bob

 

[Charles Reese]

just FYI (not to hijack your thread!) ... the earliest had a very different wedge ... circular ... also a slightly different backing plate

 

[BRENT in 10-uh-C]

Bob, PM me your email address and I will send you a copy of the print.

 

[100IH]

Thanks for bringing this subject up. I am really interested in the early wedge with the large hole vs. the later vertical slot. Strikes me as an early solution of a floating link between the shoes. It has always been difficult to evaluate the condition (wear) of the wedges. Never ran into the v.early type.

 

[BillCNC]

Won't you need a (Y) axis measurement locating the center of the slot?

Regards
Bill

 

[Bob C]

I think this is Brent's pic.

Bob

 

[Flathead]

Never knew about those early wedges, how long were they used?

 

[Kurt in NJ]

I don't have measurements, the factory one are machined where the roller rides- and the center slot is machined

 

[Bob C]

The wedge Ford used in 1935 looks similar to the very early model A one.

Bob

 

[Kevin in NJ]

The wedge Ford used in 1935 looks similar to the very early model A one.

Bob

I can assure you the 35-36 wedges are not even close. They are thin and have a ball on top, not a socket.

 

[Kevin in NJ]

I should add that someone was nice enough to look up some info about brakes for me a bunch of years ago. He found what I was looking for and was amazed at the prints. The person went to BH regularly and had never been in the brake prints.

What amazed him was the print on brake operation and the .001" tolerances and what the movement of the wedge was supposed to do.

I bring this up because the common 'wisdom' was to file the wedge areas that were worn so you could reuse them. The problem is now you have changed the angle and width per length of movement. Imagine if you have a difference in wedge ramps side to side. They may brake evenly for a short bit then one might come on stronger then the other for the same push on the rod.
Assuming they make the new wedges all the same you would be much smarter to not fool around with used.

 

[Railcarmover]

Say what you want those hand drawn prints are works of art..

 

[Charles Reese]

from what i have been able to determine ....

(A2050/A2051) FRONT BRAKE OPERATING WEDGE
{Non-J.S.}:
● (BOP-Dec’27) (~2,500 vehicles): circular wedge
● (BOP-March’28): circular wedge (floating) changed to slotted hole

End of cadmium plated stud should ‘show’ on outside of backing plate

*A21789 Operating wedge stud castle nut: 7/16”-20 (3/8” x 5/8”) ...{cadmium}
*A22302 Operating wedge stud washer: 7/16” (1/8” x 1-1/2”) ...{unfinished}
*A23551 Operating wedge stud cotter: 1/8” x 3/4" ...{unfinished}

i have been told the reason for the change was that if braked hard the wedge would become displaced and hold the shoes closed... thus the 'slotted' variety