This section covers the individual components that make up the complete fuel delivery system, from the tank outlet through the pump to the carburettor feed. The layout and part specifications differ between the standard TD, the TD Mark II with its dual-pump arrangement, and the TF, with a further split within the TF range at the fuel pump change.
Fuel Pumps and Service Parts
The SU electric fuel pump is supplied in its original points-type configuration or in an updated electronic version replacing the contact-breaker points with solid-state electronics. For the late TF chassis-mounted pump, two electronic variants are available, one for positive-earth cars and one for cars converted to negative earth. Diaphragm assemblies, mounting kits, rubber pads, retaining plates, bolts, washers, and the late-TF pump rubber cover are all available individually. The outlet elbow, union nut, and olive allow the flexible delivery hose to be renewed without replacing the pump.
Fuel Tank Hardware
The TD sender is a simple low-level switch driving the green dashboard warning lamp when fuel runs low; the TF uses a similar arrangement driving the blue low-fuel warning lamp on the instrument panel (the TF has no continuous fuel gauge, the three-in-one panel carries the ammeter, oil pressure, and water temperature gauges). It fixes to the tank by six pan-head screws through a cork gasket. The filler cap is common to TD and TF in the original pattern, with a TC-style alternative available; release clip and filler seal are common to both. Rubber pads, packing strips, straps (primed or chrome), strap hardware, and drain plug complete the mounting.
Tank sealant is available for internal corrosion, modern ethanol accelerates deterioration, and sealing a marginal tank is a practical alternative to replacement.
TD Fuel Line Layout
The standard TD fuel line runs from the tank outlet via a rigid pipe along the chassis rail to the SU pump on the bulkhead, then via flexible hose to the rear carburettor banjo union, and from there via a short inter-carburettor hose to the front carburettor. Six to seven pipe clips secure the fuel and brake pipes to the chassis (varying by LHD/RHD). Each banjo connection uses a banjo bolt with fibre washers, which should be renewed whenever the joint is disturbed. A double banjo union forms the distribution point between pump delivery hose and inter-carburettor connection.
TD Mark II Dual-Pump Layout
The Mark II's dual-pump arrangement creates a more complex fuel line system. Each pump feeds an individual carburettor through separate delivery lines: a dedicated pipe from tank to each pump, a primary-pump-to-rear-carburettor hose, a carburettor-to-carburettor hose, and a secondary-pump-to-adaptor-to-front-carburettor line. An additional adaptor connects the secondary pump output into the front carburettor feed. Eleven pipe clips secure the fuel and brake lines, significantly more than the standard TD, reflecting the additional pipework for sustained high-speed competition fuel demand.
TF Fuel Line Layout
The TF fuel line layout splits at chassis 1509/1510. Early TFs up to 1509 follow the TD pattern with the low-pressure pump on the bulkhead, the same tank-to-pump pipe, pump-to-rear-carburettor hose, inter-carburettor hose, and banjo connections as the TD. From chassis 1510, the routing changes to accommodate the chassis-mounted high-pressure pump on the right-hand chassis side member: new tank-to-pump and pump-to-hose fuel pipes, a different pipe-to-rear-carburettor hose, a revised carburettor-to-carburettor hose, and a different pipe clip quantity (with a further increase for left-hand drive cars).
Banjo Unions, Clips and Sealing Hardware
Fuel pipe connections use banjo bolts with fibre washers at each joint, with the inter-carburettor connection typically using a double banjo union. Fuel and brake pipes run together along the chassis rail, secured by combined pipe clips (quantity varying by model and drive-hand) and held to each other by pipe straps. P-clips, olive unions, and tube nuts are supplied individually. Fibre washers should always be renewed when any joint is disturbed, as weeping banjo joints are a known weak point on systems of this age.
Ordering Considerations
Chassis number and model are both essential when ordering fuel lines. The TD, TD Mark II, early TF (to 1509), and late TF (from 1510) each have distinct layouts, and LHD/RHD cars use different pipe clip quantities. Banjo bolts, fibre washers, and pipe clips should be renewed at every fuel line replacement rather than reused.
When ordering a fuel pump, confirm model year and, for the late TF or negative-earth conversions, electrical polarity.