Basically you're applying the same mount of force, from your foot, across a smaller area in the master cylinder. Manual brake cars have a 1 1/8' bore master cylinder. The smaller bore master cylinder has a 7/8' bore, and it comes with cars equipped for power brakes. Scott suggested changing the master cylinder on manual-brake cars to reduce pedal effort. On his own 1973 with the same 7 1/4” axle as our 1974, the 13/16” wheel cylinder reduced lockup but did not eliminate it.) Reducing pedal effort (He also suggested that on cars with the heavy 8 3/4” axle, using a 13/16” unit. Daniel suggested the 3/4 inch rear wheel cylinders with our setup - parts: NAPA 37863, Raybestos WC-37863, Bendix 34076, Wagner WC123412, Centric 134.67015, or Chrysler 4423 852.

This reduces braking power to the rear wheels, balancing the system more effectively so that they are not so prone to lockup. Two approaches were suggested, one by Daniel Stern, and one by Scott Sigethy.ĭaniel Stern wrote that the key was to replace the rear wheel cylinders with smaller bore versions. However, the rear tires lock up far too quickly when the brakes are applied in emergency situations. This is in many ways the best setup, since it incorporates the more effective discs without the loss of control that comes too often with the power brakes. Our 1974 Plymouth Valiant has manual disc front brakes and, along with every other Valiant, drums in back. Avoiding wheel lock (lockup) when you hit the brakes

Allpar, LLC cannot take any responsibility for the outcomes of these processes. Brake upgrades: power brakes, master cylinders, and avoiding lockup

Instaling The Valiant