Broke Brake

[varmint]

It's more stuck than anything. I replaced the three pedal return springs and tested the brakes (stopped the wheels from turning) but it stayed.
1) Pedal is wedged against the hogshead.
2) Back and forth play in the pedal.
3) Gap in the brake pedal.
So, how to fix?

brake 01.jpg (85.73 KiB) Viewed 5701 times

[KWTownsend]

I think that your band is probably not tight enough.
Do you put on new pedal cams while you had it apart?

[Mike Silbert]

While I feel you have an adjustment or wear issue I would still adjust the brake pedal a bit. Straighten the curve at the bottom a touch so it clears. Then adjust the top curve to fit the pedal trim slot. Pedals are often found to be bent poorly after 100 years of "experience". Model T brakes are not that good so we need all the help and travel we can get. That extra distance might matter some day.

[speedytinc]

From your 3 descriptions & the last pix I have to ask: Are you aware the brake pedal shaft pulls the band tighter as the pedal gets up on the cam?
The pedal pushes away from the HH base cam thus pulling the band ears closer together. None of your pix show the movement of the pedal outward activating the brake band.
Or is it possible the pedal shaft fit is too tight to freely return back to its neutral position?

I notice the cams look dry. Put some oil on the faces. without lubrication, cam faces will Gall & bind up to the extent full leg pressure wont activate the brake. I have experienced this myself with well sealed (leak-less) pedal shafts. Sealed shafts must have the cams manually lubricated.

[Jerry VanOoteghem]

I don't know about others here, but I'm not really sure what the problem is. Your title says, "Broke Brake". What is "broke"? Does your pedal stick down when you apply the brake? If that's it, and if it's caused by the pedal arm jamming against the hogshead, realize that most likely, when the floorboard is installed, it will prevent the pedal from traveling far enough to jam up like that. Other than that, I can't see anything else that appears to be wrong.

[varmint]

Thanks for all the sound advice.
I agree that the band needs to tightened. Time to read the book again.
No, I did not buy a new pedal cam. I see that they are available. But, it may be the pedal that is worn.
I will get a straight on look and photo if the pedal is bent from 100 years of experience.
By adjusting the top and bottom curves...my mind says weld to fill in and grind to match? (This is within my means.)

Yes, I'm aware that the pedal lever needs to contact the cam before the pedal is forced to the left.
Pressing the brake does stop the wheels.
The shaft moves freely...until it contacts the hogshead.
I know that there is some lubrication, because I have oil leaking out there.

Here is a close up to show that the pedal does push left a bit and that it hits the hogshead.

brake 01a.jpg (79.87 KiB) Viewed 5382 times

[Jerry VanOoteghem]

The pedal motion to the left appears to be fairly minimal, given that the pedal is now fully depressed. If you had more travel to the left, your pedal wouldn't hit the hogshead so soon. It makes your pedal cam & pedal* suspect for too much wear.

*A new cam is only 1/2 of the equation. Wear in cam surface of the pedal will also limit motion. It's not much good to replace one and not the other.

[Allan]

Be very cautious about adjusting the brake band some more to correct the problem. The adjustment should be made under road conditions. Adjust only enough to make the brakes work as they need to.
As others have said, replace the ramp with a new one, and rebuild the ramp on the pedal. There should be little play between those two components. The moment you press the pedal, it should immediately ramp up.

Allan from down under.

[varmint]

So, I pulled it and took more photos.
Brake pedal does not pull back in position as much as the other two pedals.

brake 06.jpg (104.83 KiB) Viewed 5221 times

brake 07.jpg (44.72 KiB) Viewed 5221 times

Front side that was already shown:

brake 08.jpg (47.43 KiB) Viewed 5221 times

Back side:

brake 09.jpg (27.69 KiB) Viewed 5221 times

brake 10.jpg (59.66 KiB) Viewed 5221 times

[KBurket]

I had found a similar situation when I rebuilt one of my hogsheads. The brake pedal was rubbing against the side of the hogshead and was easily remedied by bending it to the left.
I used a large crescent wrench to grab the peddle on top by the foot rest. It’s smarter to use two wrenches as discussed in Dan T’s post here:
https://mtfca.com/phpBB3/viewtopic.php?t=27309
If you still have it pulled, you could straighten it in a vise.

[Jerry VanOoteghem]

So, I pulled it and took more photos.
Brake pedal does not pull back in position as much as the other two pedals.
brake 06.jpg

brake 07.jpg

Front side that was already shown:
brake 08.jpg

Back side:
brake 09.jpg

brake 10.jpg

Your first photo, looking straight at the pedals, makes it appear that your brake pedal is bent somewhat to the right. Bending it to the left, and checking that it still fits in the floorboard pedal slot, may help you a bunch.

As for the brake cam, I would buy a new one and at the very least, use it as a gauge to determine what wear you may have in your current cam & pedal. If you confirm wear, you can use the new cam and weld & trim the mating pedal cam to match.

[varmint]

Yes, it is still out of the transmission. I removed some paint for the torch, before twisting the pedal and bending the shank back to the left.

brake 11.jpg (59.82 KiB) Viewed 4844 times

brake 12.jpg (66.89 KiB) Viewed 4844 times

That hole in the 1/4" pin is there because I drilled it.

brake 14.jpg (38.98 KiB) Viewed 4844 times

I found green paint in the center of the cam's contact, indicating a lack of wear, probably because somebody has already replaced it.

brake 13.jpg (37.21 KiB) Viewed 4844 times

The pedal, however, has worn so much that it has ridges.

brake 15.jpg (54.75 KiB) Viewed 4844 times

[Allan]

The green paint on the ramp may be there simply because it has not been making contact with the wear surface on the pedal. It could still be worn. It is cheap insurance to replace it with a new one while you have it torn down.

The ramp on the pedal will need to be rebuilt with weld, and hand worked back to a good fit with the ramp. That wear surface is a spiral rather than a straight ramp. When dressing it back you will need some blue. Both sides of the pedal ramp need to be worked on until each makes good contact with the ramp surface. When you have finished there should be very little pedal motion before it begins to ramp up.

Once you have that sorted, then you can bend the pedal arm back to align it with the others.

Hope this helps.
Allan from down under.

[Jerry VanOoteghem]

Once again, buy a new cam. It will show you the correct ramp. It would be a waste of time to fit the rebuilt pedal to a worn cam.

[Henry K. Lee]

From experience a spring roll pin will shear…, use a solid metal round stock and pen the ends.

Just Sayin’

[varmint]

First the photos:

brake 16.jpg (34.56 KiB) Viewed 4454 times

brake 17.jpg (46.08 KiB) Viewed 4454 times

brake 18.jpg (11.75 KiB) Viewed 4454 times

brake 19.jpg (60.12 KiB) Viewed 4454 times

The retaining washer had to get bent back into shape to be useful again. However I'm still using the double lock nut setup. I packed the pedal/cam with grease to slow down the oil leak past the new O ring.

It works. It clears the hogshead. It returns. I'm still certain that someone before me swapped out the support cam without repairing the pedal. But if anyone is interested in providing measurements of the cam, I'm willing to check it out.

[Allan]

It doesn't matter what the measurements of the cam are. When you rebuild the pedal ramps they are finished to fit the cam. A new can gives you positive starting reference and you bring the pedal up to its specification.

Allan from down under.

[varmint]

brake 20.jpg (59.95 KiB) Viewed 3832 times

The new cam arrived and I removed the brake pedal again but the new part has about 1/64" play whereas the one I built up has none. So, the cam that came with the coupe is back on it and all it sorted out with the brake band for now. The new part will go into my spare parts tool box.