Drum brake systems rely on a small hydraulic component called the wheel cylinder to convert braking pedal pressure into mechanical force at the shoes. When the driver applies the pedal, brake fluid pressure travels through the system and pushes two opposing pistons outward inside the cylinder, forcing the brake shoes against the inner surface of the drum. Because this component operates under continuous thermal and hydraulic cycling, the internal rubber seals eventually harden and crack — the defining failure mode is a weeping cylinder that leaks brake fluid onto the shoes, contaminating them and causing a sharp reduction in braking effectiveness on that corner of the car. A soft or spongy pedal that worsens over time is another indicator, especially when combined with a low fluid reservoir despite no obvious external leak. Wheel cylinders are straightforward to replace, but the correct OE number matters because piston diameter, bore, and the thread specification for the bleed nipple all vary between chassis. TRW and Bosch are among the primary original-equipment producers for drum brake hardware, covering the range from Renault and Peugeot city cars to Ford and Toyota commercial derivatives. As a rule, cylinders on the same axle should be replaced in pairs to preserve equal braking force distribution across both rear wheels.
Wheel cylinders are chassis-specific: piston diameter, bore length, and bleed nipple thread differ between vehicle lines and even between front and rear axles on the same model. Use the make-model-year-engine selector on this page to filter results to your exact vehicle. You can also check the part number cast or stamped onto the body of the existing cylinder and match it against the OE numbers listed. Confirming the OE reference means you won't need to source adaptor fittings or re-bleed repeatedly due to mismatched bore sizes.
Yes — as with all drum brake hardware, it is strongly recommended to replace wheel cylinders in axle pairs. The internal seals age at the same rate on both sides of the car, so a single-sided replacement often leads to the opposite cylinder failing within months, requiring the same labour again at additional cost. Replacing both sides in one visit also ensures equal hydraulic pressure delivery to both brake shoes, preserving straight-line braking balance and reducing wear on the new drum and shoe contact surfaces.
OEM wheel cylinders are produced to the vehicle manufacturer's original specification, typically by tier-one brake suppliers such as TRW or Bosch. Quality aftermarket equivalents from established names like KAWE or LPR are manufactured to the same bore tolerances and seal specifications and are fully compatible. Budget alternatives may use lower-grade rubber compounds for the internal seals, which can harden or swell prematurely — particularly in climates with significant temperature variation — shortening service life considerably compared with OEM parts.
The classic symptom is brake fluid weeping past the piston dust boot and onto the rear drum and shoes, which causes a noticeable reduction in braking on that corner — the car may pull to one side under moderate braking. Other indicators include a soft or gradually sinking pedal despite a full fluid reservoir, a burning smell from the rear of the car during light braking due to contaminated shoes dragging, and visible corrosion or swelling around the cylinder body on older vehicles that have been exposed to road salt.
Showing 100 of 14,361 Brake Cylinder OE numbers. Enter the OE on the main OE search to jump to any reference.
