Brakes help

[Dave Noll]

Originally Posted by Mark Yacavone

Okay. First step is take the pedal out and drill a hole about an inch up. They are case hardened , so use a drill press.
That's the free one , before getting out the Plasti-Card.

Umm, If it is actually Case Hardened, A solid carbide drill bit is not going through it. I like the welding in an extra 2", that will give more leverage but will put the pedal close to the floor.

My car has 2 stubs welded on the brake pedal lever from the factory. I also put as large of a Rear wheel cylinder I could find on the Fronts. (4 wheel drums)

[Mark Yacavone]

Originally Posted by Dave Noll

Umm, If it is actually Case Hardened, A solid carbide drill bit is not going through it. I like the welding in an extra 2", that will give more leverage but will put the pedal close to the floor.

My car has 2 stubs welded on the brake pedal lever from the factory. I also put as large of a Rear wheel cylinder I could find on the Fronts. (4 wheel drums)

Maybe not the correct term, but definitely hardened ..You could see it on the metal.
It creaked and groaned and smoked , but it went, on a good size drill press . Kinda like drilling a center bolt into mono leaf springs..Ahnold probably could have done it a little easier.

[Alan Nyhus]

Originally Posted by Dave Noll

Umm, If it is actually Case Hardened, A solid carbide drill bit is not going through it.

Case hardening only hardens the surface. The material under the hardened surface remains unaltered. -Al

[jerry witzel]

Here's an adapter for the master cylinder. https://www.ebay.com/itm/Pro-5-0-79-...wAAOSw7cZcM86v

[Dave Muller]

For what it's worth I changed the pedal ratio and wound up never installing the proportioning valve that I bought. If anything the pedal is a little soft, but I can get over 1000 PSI easily in one shot and it holds fine on the line (as long as the 2-step in on...).

It took a could of tries to find the right bore size for the master cylinder but it was worth taking the time to work it out. I wound up with 1 1/8 inch.

[RobbieRacer]

Originally Posted by jerry witzel

Here's an adapter for the master cylinder. https://www.ebay.com/itm/Pro-5-0-79-...wAAOSw7cZcM86v

I have one of these already

[Mark Yacavone]

Originally Posted by Alan Nyhus

Case hardening only hardens the surface. The material under the hardened surface remains unaltered. -Al

Makes sense. Might be then. Once you get the drill bit started, it'll go.
I'm sure the pedal arm is hardened for safety reasons.

[Dave Noll]

Originally Posted by Mark Yacavone

Makes sense. Might be then. Once you get the drill bit started, it'll go.
I'm sure the pedal arm is hardened for safety reasons.

Originally Posted by Alan Nyhus

Case hardening only hardens the surface. The material under the hardened surface remains unaltered. -Al

Machining through a 60Rc surface can be done, but not easily at all.

Speeds and Feeds
SFM IPM DOC (Inch Depth of Cut)
Carbon And Alloy
Steels (50-60 Rc) 300-500 0.002-0.008 0.003-0.020
Die Steels (55-65 Rc) 150-350 0.002-0.008 0.003-0.008

[RobbieRacer]

Originally Posted by Dave Noll

Umm, If it is actually Case Hardened, A solid carbide drill bit is not going through it. I like the welding in an extra 2", that will give more leverage but will put the pedal close to the floor.

My car has 2 stubs welded on the brake pedal lever from the factory. I also put as large of a Rear wheel cylinder I could find on the Fronts. (4 wheel drums)

Mine only has one stub and it's also welded on.