This section covers the brake fluid circuit from the foot pedal through the master cylinder, rigid pipe network, and flexible hoses to the wheel cylinders, the pressurised system converting pedal effort into braking force at all four wheels. The TD and TF use a Lockheed single-circuit hydraulic system, common to both models, with variations limited to brake pipe routing and clip count for LHD and Mark II cars. Clutch operation is mechanical (cable or rod, by chassis number), not hydraulic, only the brakes use hydraulic actuation.
Section Layout
The Hydraulics section is divided into four sub-sections: Master Cylinder covering the cylinder, repair kit, push rod, fork end, and mounting hardware; Brake Pedal and Fixings covering the pedal shaft, brake and clutch pedals, alloy and rubber pads, return spring, and bulkhead fume excluder; Brake Lines covering the copper pipe kit, distribution adaptors, flexible hoses, brake light switch, pipe clips, and pipe bending tools; and Clutch and Brake Fluid covering the brake fluid options and bleeding equipment.
Master Cylinder Overview
The Lockheed single-circuit master cylinder converts pedal force into hydraulic pressure. The cylinder, repair kit, internal spring, circlip, filler cap with sealing washer, push rod, fork end (with LH-threaded lock nut), and mounting hardware are all available individually. The master cylinder adaptor connects to the first rigid brake pipe, sealed with a copper washer. A failing master cylinder typically gives a spongy pedal, a pedal that sinks under sustained pressure, or visible fluid leakage around the push rod seal.
Brake Pedal Overview
The brake pedal shares its shaft with the clutch pedal, a single pedal shaft carries both pedals, with spacing washers, circlips, and bushes providing the pivot arrangement. The brake pedal itself is specific to left-hand and right-hand drive, with the left-hand-drive pedal incorporating an extension to bring the pedal pad into the correct position for left-foot-side operation. Both pedals use a rubber pad over an alloy backing plate. A return spring ensures positive pedal return after release.
A rubber fume excluder seals the pedal shaft's penetration through the bulkhead, preventing engine bay fumes from entering the cockpit.
Brake Lines Overview
A complete copper brake pipe kit provides all the rigid pipes from the master cylinder through the three-way and four-way distribution adaptors to each wheel's flexible hose connection. The pipe kit is specific to left-hand or right-hand drive, since the master cylinder position and pipe routing differ. Three flexible rubber brake hoses bridge the chassis-mounted rigid pipes to the moving components: one to each front wheel (spanning the front suspension travel) and one to the rear axle (spanning the axle movement on its leaf springs). The number of pipe-to-chassis clips required varies between specifications: six clips on a standard TD or TF, seven on a TF LHD, and eleven on a TD Mark II.
Brake Fluid Overview
Brake fluid is available in standard DOT 4 (Castrol Response, normal road use), Super DOT 4 (covering DOT 4 and DOT 5.1, high-performance use), and SRF (competition grade). Silicone brake fluid is a non-hygroscopic alternative, it does not absorb moisture, strip paint, or require the periodic fluid changes that glycol-based fluids do. This makes silicone particularly suitable for cars in intermittent use. A Gunson Eezibleed kit simplifies single-person bleeding.
Hydraulic System Maintenance
Conventional glycol-based fluid is hygroscopic and gradually absorbs atmospheric moisture, lowering its boiling point and increasing vapour-lock risk. DOT 4 and Super DOT 4 should be changed every two years regardless of mileage. Brake hoses deteriorate internally long before external signs appear, internal swelling can create a one-way valve effect, causing the brake to bind. Hoses and rubber master cylinder seals should be renewed preventatively, particularly on laid-up cars.
Ordering Considerations
Confirm the drive side (LHD or RHD) when ordering brake pipe kits, F180 (RHD) and F180L (LHD) are dimensionally different. Confirm whether the car is a TD Mark II (eleven pipe clips) versus standard TD/TF (six clips, or seven for TF LHD) when ordering a complete clip set. The brake pedal is also LHD/RHD specific, RHD cars use the standard pedal, LHD cars use a pedal with an integral extension. Master cylinder, repair kit, flexible hoses, distribution adaptors, brake fluid, and bleeding equipment are all common between TD and TF.