The rear brakes use a single wheel cylinder per drum that floats on the backplate, applying equal force to both shoes, one shoe becomes leading and the other trailing depending on the direction of wheel rotation. The 9-inch drum and 1½-inch lining specification is shared with the front. Each rear cylinder also incorporates the handbrake lever pivot, so the same shoes are operated mechanically by the handbrake and hydraulically by the brake pedal.
Wire Wheel Brake Drums
The same separate brake drum used at the front of wire-wheeled cars is also used at the rear, a single common part number serves both axles. The drum is mounted to the splined hub by twelve drum-retaining studs and nuts and secured by lock tabs, with a rubber inspection plug providing access to the brake adjuster. Steel-wheeled cars do not use this separate drum, their rear brake drum is integral with the hub assembly, in BSF (TD to chassis 12284) or Unified (TD from 12285 and all TFs) thread specification. Rear hub and integral drum components for steel-wheeled cars are covered under Rear Axle & Propshaft.
Wheel Cylinders
Two rear wheel cylinders are used, one per drum. Each cylinder is supplied complete with the handbrake lever already fitted, but without the rubber boot that seals the lever's penetration of the cylinder body. The repair kit for each cylinder includes a seal and the handbrake lever boot, allowing a leaking cylinder to be rebuilt rather than replaced.
The rubber cups inside the cylinder are also available individually. Unlike the front cylinders with their double banjo distributing fluid between two cylinders per drum, each rear cylinder takes its hydraulic supply through a single banjo connection, secured by a banjo bolt and sealed with copper washers. The bleed nipple on each cylinder allows the hydraulic circuit to be purged of air during bleeding.
Handbrake Lever Mechanism
Within each rear cylinder, the handbrake lever pivots on a separate pivot pin, transferring the cable's pulling force into the same outward movement of the cylinder pistons as is produced hydraulically by the brake pedal. This shared mechanism means the handbrake operates the same shoes, and provides the same braking force per millimetre of cylinder travel, as the foot brake.
The rubber boot that seals the handbrake lever pivot is a known maintenance item: when it perishes, water and grit enter the cylinder body and accelerate corrosion of the cylinder bore. It is included in the rear cylinder repair kit and is also available separately.
Brake Shoes and Linings
Rear brake shoes are supplied as the same asbestos-free axle set used at the front, a single shoe specification serves both axles. Brake linings are also available as an axle set for owners re-lining their existing shoes. The shared shoe specification simplifies parts identification: one set of brake shoes for the front, another identical set for the rear.
Spring Arrangement
The rear brake spring arrangement is more complex than the front because the single floating cylinder requires careful shoe location. A pull-off spring at the cylinder end returns both shoes when the brakes release; a tension spring at the abutment end keeps the trailing shoe seated. Four steady springs (two per drum) hold the shoes flat against the backplate. Steady springs were added during production to improve shoe stability, very early TDs that lack them should have them fitted during reassembly to bring the brake to current specification.
Brake Shoe Adjusters
Each rear drum has a single Lockheed "Microm" snail-cam adjuster, one mask and one adjusting cam per drum, since there is only one cylinder per drum. Rear brake adjustment is carried out the same way as the front: the adjuster is tightened until the shoe just contacts the drum, then backed off the smallest amount that allows the wheel to spin freely without binding. Brake assembly lubricant on the cam contact points and shoe-to-backplate contact points prevents adjuster seizure and shoe binding.
Ordering Considerations
Most rear brake components are common between TD and TF: cylinders, repair kits, banjos, shoes, linings, springs (pull-off, tension, and steady), adjusters, and bleed nipples. The wire-wheel brake drum and its mounting hardware are specific to wire-wheeled cars (and shared front and rear); steel-wheeled cars use the integral hub-and-drum assembly listed under Rear Axle & Propshaft. Wheel studs and nuts are thread-specific (BSF to chassis 12284, Unified from 12285 through all TFs). Brake shoe steady springs should be confirmed as fitted on very early TDs.