[CompClassics]

The booster attached to the front only works properly by itself, remember you are only trying to reduce the drivers effort in braking, most of the vehicles braking performance is from the front brakes per design. This is why typical automotive and even motorcycle brake systems utilize smaller components at the rear of the vehicle and larger components in the front, sort of a fixed brake bias system.
The MGC/GTS I spoke of restoring previously had had only a front brake booster on it for many years of driving although it was originally built with two brake boosters, it was not known when or by whom the rear brake booster was removed? I had to refabricate the rear brake booster system from photographs that were taken when the car was first being built by MG. It was interesting to note the rear brake boosters mounting position was in the passengers footwell inside the interior of the car.