Brake pedal free play

[Eric Sole]

I'm trying to establish if the cam portion of my brake pedal is worn enough to warrant replacing the pedal. The pedal stroke seems to be too short, and so the band needs to be overly tightened to compensate, at least it seems that way.
The pedal supports are new reproduction parts.

Question: How much pedal free play can be considered within limits? That is to say, if you step on the pedal first, and then pull the pedal backward, how far does it move?

I placed a horizontal tape measure from the firewall and measured at the center of the pedal tread (as shown in the pictures) with these results:
- Brake 15/16" (24mm)
- Reverse 9/16" (14mm)

Does anyone have similar measurements AND good, efficient action on the brake pedal?
Thanks for sharing your results.

[Allan]

A new bolt in pedal ramp is only half a repair. The pedal ramp itself will also be worn, and that wear is manifest in the free play you have in the pedal. You can bend the pedal back, with heat, to compensate for the travel so that it does not bottom out on the floorboard slot. The pedal ramp can be addressed when next you have the hogshead off.
Others may have different ideas.

Allan from down under.

[Dan Hatch]

Good cams on brake pedals are getting harder to find.
They are all 100 years old. And what pedal gets used more?
Best fix is a new Rocky Mountain brake pedal and new cam.
But that should also include rebushing the Hogs Head. Good luck Dan .

[Eric Sole]

I am going to assume then, that the ideal pedal play is "zero", and that the shaft should begin to move outward (axially) from the very start of the pedal being pushed. This gives me an idea of how much loss of outward movement my pedal has.

The hogshead has already been bushed when the pedal shafts were replaced, and a seal has been installed on the clutch shaft. Everything's been replaced except the pedals themselves.

Bending the pedal arm seems like a fairly easy compensation.

I hadn't thought about getting a Rocky Mountain brake pedal. Not cheap, but at least they're available.

Thanks for your suggestions!

[Eric Sole]

Has anyone built up the pedal ramp with weld and dressed it down? If so, how did that work out? Would it be preferable to bending the pedal arm to compensate wear?

[speedytinc]

Has anyone built up the pedal ramp with weld and dressed it down? If so, how did that work out? Would it be preferable to bending the pedal arm to compensate wear?

Yes. Of course, the shaft has to be removed.

[Allan]

On our RHD cars, it is the first gear pedal that is internally adjusted. Rebuilding the ramps on the pedal requires removal of the pedal shaft prior to welding up the worn ramp. With a new notch in hand to act as a reference, the welds can be ground/filed back to make the fit. Bearing blue will tell you where the weld needs removing. Both side of the ramp need to be worked back at the same time, and it will take time to do a good job. The actual surface left will be a spiral when you have finished. Yes, the brake and reverse pedal should begin to travel sideways immediately pressure is applied to the pedal. Read minimal free play.
On my first clutch pedal rebuild the ramps and the spiral were reworked with minimal freeplay. The result was no free pedal to get neutral between gears. Lesson learned.
it sounds like your hogshead had all the work done except the bit that takes most time.

Hope this helps.
Allan from down under.





Allan from down under.

[Eric Sole]

With all the oil leakage I used to have at the pedal shafts, any wear at the cam area should have been minimal, haha.

Thanks for your input Allan. I'm beginning to get an idea of what's involved. Fortunately, I won't have to worry about the free neutral in this case.

The LHD clutch pedal cam works in a constantly oiled environment, which brings up a new question: Is the clutch pedal cam typically free of wear?

[speedytinc]

Eric, When the pedal shafts are efficiently sealed, The cam ramps can & do get dry to the point the pedals wont move. Will gaul. Actually lock up the ramps. The low pedal shaft & clutch shaft need a drop or 2 occasionally also.
So they must be manually oiled. The original system self lubricated the ramps. There is that small price to pay for sealing those shafts.

[Eric Sole]

Strike my last question: Is the clutch pedal cam typically free of wear? I had forgotten that both pedal cam and fixed cam are available for the clutch pedal. Both have been replaced.

I installed O-ring seals behind the brake and reverse pedal supports (fixed cams), but since I had bronze bushings installed in the hogshead when I replaced the pedal shafts, I'm thinking the O-rings are just overkill since very little oil is likely to get past to the outside of the hogshead.