A wheel cylinder is made of grey cast iron or aluminium and is a part of hydraulic drum brake. When brake pedal is applied, a hydraulic pressure is generated in the master brake cylinder which is transmitted to the wheel cylinder in the brake fluid via the brake lines and exerts pressure on brake shoes to press them against the brake drum. When you replace the brake shoes or the brake drums it is advisable to replace the wheel cylinder at the same time. Check our Automotive Parts online store to buy best quality brands like KBX Wheel cylinder, Bosch wheel cylinder. In case of any query do get in touch with us.