Join Date: Aug 2010
Location: Ulster County, New York
Bronco Info: 1978 Cummins Bronco
I upgraded the front calipers with pieces from a 1975 full size passenger car (aka "Thunderbird calipers") with the larger pistons, the calipers have a lot more clamping force than the stock units. Stock rotors and pads work with the bigger piston calipers, too. I did have to modify the hoses to work with the calipers, but not a big deal. I drilled out the stock banjo fitting slightly larger, and used larger banjo bolts that fit the calipers. (the thunderbird calipers normally use hoses that thread right into them, not banjo bolts and fittings, but there is clearance issues with that if used on the Bronco) Some very careful grinding was needed on each caliper to clear the banjo fittings as well.
I had already upgraded the master cylinder and brake booster, and rear wheel cylinders with larger F350 parts, so the addition of the larger piston calipers completed the brake upgrade. It can lock up the 37s on dry pavement now. Not surprising, since the vacuum pump on the diesel sends 27" of vac to the F350 brake booster. I'm very happy with how the brakes work now.
1978 Bronco Custom, 6" skyjacker & 3" body lift, 37x12.50R16.5s, posi front diff, 3.50 gears, Dynamic Racing C6 w/billet 1200 rpm converter, upgraded brakes, '91 Cummins 12V, Denny T fuel pin, injection pump maxed out & timing advanced, 3800 gov. spring, 60# valve springs, ARP head studs, 4" exhaust.