The Oldsmobile drum brake wheel cylinder makes use of an old technology, but it is still effective in bring your vehicle to a stop safely. This brake component performs a similar function as the disc brake caliper, but the drum brake wheel cylinder has pistons that move outward in opposite directions instead of inward in the same direction. The drum brake wheel cylinder pistons push the brake shoes out against the inside of the drums. The calipers move the piston against the brake pads and squeeze them against the disc. On an Oldsmobile, depending on the year of production, you may find drum brakes on the rear and the front. The way the drum brake wheel cylinders fail is the same as the calipers; it is a seal holding back the hydraulic fluid in the system. When the seals fail and the brake fluid leaks out of this brake component, the stopping potential of the drum brake decreases. This is not only because the brake system's ability to build up pressure is reduced, but the brake fluid then coats the inside of the drum reducing the amount of friction that can be generated from the contact of the brake shoes and the brake drum. This is a potential hazardous situation for the owner of the Oldsmobile to be in. The Oldsmobile drum brake wheel cylinder failure can be identified by a softness in the brake pedal when pressure is being applied along with a puddle of brake fluid near the rear wheel of the vehicle. If the drum brake wheel cylinder is not replaced in a timely manner on the Oldsmobile then total brake failure will occur in a short allotment of time which can cause an accident.