More disc brake questions

brian6pac said
O.K. 72bluNblu Just a FYI you said that you changed to 1.12 Tbars and the front would lock before the rear, Yes now you don't have the weight transfer to the front so you need to put the valve in the front line to reduce and balance the braking force!! It's not just for the rear. It's when some guy doesn't fully understand or care how it works, that's when he gets out of control and crashes into someones car that does.

brian6pac said
You don't want ether end to lock first, all 4 at the same time!! Front locks first and it understeers, pushes, plows,
wont turn. Rear locks first oversteer, rear comes around, spins out, but you can control it if you know how to drive. Understeer is very hard to get under control, once you get off the brakes the car is still sliding if you are in corner usually it's to late to recover.

I'm well aware of how it's supposed to work. But even in a perfectly balanced car the odds of all 4 wheels locking at the exact same time during street driving are pretty much nil. Just look at any auto racing. When they overbrake it's almost always a single wheel locking, not even both front or rear. If you're not going perfectly straight on dry, level ground on pavement that's in good condition it's not going to be the same every time. And if you're running drums out back it's a crap shoot, the auto adjusters aren't perfect. Sometimes they're different by a tooth and one wheel will lock first, sometimes they'll both be a little tighter or looser. And I would NEVER reduce the pressure to the fronts. Ever. Increase the rear braking to match, absolutely. Dialing down the front is just increasing your stopping distance, that's 70-80% of your braking you're turning down.

Truly if you're doing it right you should be threshold braking and not locking any of the wheels. Bottom line is know your car.

moparmat2000 said
Based on this information above, a stock A body caliper piston is 2.50" diameter, and a stock A body manual master cylinder is 1-1/32" diameter bore. This is factory setup.

Cordoba brake pistons are 2.75" diameter. So according to this above information from DrDiffs website, if i use an aluminum 1-1/32" bore master cylinder in a manual brake config, which is the same as stock A body manual disc, along with 1/4" larger than stock A body piston calipers off a cordoba it should yield a softer pedal, with a firmer clamping force.

You can't necessarily compare the A-body and Cordoba systems for pedal feel. Remember that E-bodies that had manual brakes and 2.75" caliper bores used 15/16" master cylinders, they used 1 1/32" for power systems. And Cordoba's used 1-1/32" m/c's and had standard power.

Stock 73+ a-body calipers were 2.6". Not sure if that's 2-5/8" rounded off or not, some of the re-popped ones are spec'd at 66mm which is 2.6". I prefer the 15/16" master cylinder myself even with the 2.75" bore calipers. Anything from 7/8" to 1-1/32" will work.