{FORGED?} Re: brake balance

[AMC74Hornet@xxxxxxxxx]

On November 9, 2005 Tom Jennings wrote:

> My rear brakes have been grabby since day #1 (on my 70 Hornet).
> Spelunking in my notes I found out why -- the rear wheel cylinders
> are .875" (7/8"), for a four-wheel-drum-brake car, and up front I've
> got Bendix calipers. (I was gonna go all drum but chickened out and
> switched to disks.)
> 
> (Bendix caliper small cars got .8125" (13/16") rear wheel cylinders,
> at least 1979 did.)
> 
> That would explain the overactive rear brakes (too much area on rear
> pistons).
> 
> But for the record, the 1" drum brake master cylinder, and one-
> diaphragm drum brake booster, makes for excellent pedal; plenty of
> assist but nowhere near "feather touch". The bigger M.S. bore (1970
> drum 1" vs. 1979 disk brake cars got .945" (24mm) masters) raises
> pedal pressure (but lowers travel), a nice match for a modest amount
> of boost.
> 
> Yes, I popped out the master cylinder residual-pressure valve for the
> front brakes.

If the grabby rear brakes bother you just install a Wilwood in line proportional valve in the line out of the master to the rear brakes. I did and set it right in the middle of the adjustment range and never had to touch it. I am using the original 74 drum brake booster and master. Possibly the reason I really did not have to adjust the valve is because the front disc set up came from a 79 Concord and I also installed the complete rear out of the same car. But it was a non power set up when in the Concord. There is nothing like driveing through the hills where I live with out the drum brake fade I had to deal with for 30 years with this car now that it has disc's. 
"Doc"









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