Brake Master Cylinder Ford Deluxe 39-48, V8, F1 48-52 91A-2140 1939-48 Brake Master Cylinder Ford Deluxe 39-48, V8, F1 48-52 91A-2140 Bore: 1.0625 In.; w/Manual Brakes Features & Benefits: This brake master cylinder is precision-engineered to match the design, function, and performance of the original master cylinder on specific vehicle years, makes and models.