If there's enough fluid displaced to get the shoes firmly applied to the drums, the smaller cylinder will require less pedal effort. There's more hydraulic advantage, which equates to less pedal effort for the same braking effect. HOWEVER, and this one's very important, even a slight amount of brake lining wear will allow the pedal travel to increase to a dangerous distance. You'd need to be very careful to keep the brakes adjusted often. I've had problems with a Dodge 1-ton motorhome running out of pedal stroke when a very slightly too-small MC was installed. It almost wrecked us on more than one occasion. The problem turned out to be caused by a MC with a reservoir that was too small for the size of the rear brake cylinders. A disc/drum MC had been substituted for the correct drum-only cylinder.
Jerry
