Question 1

Floor Pan Corrosion

Accepted Answer

Visible rust perforation on the underside of the floor. Soft, spongy metal when prodded. In severe cases, daylight visible through the cabin floor. Water enters the cabin through deteriorated door seals, windscreen rubber, and the firewall. Road spray attacks from below. Australian conditions, heat, humidity in the north, salt air on the coast, accelerate the process. Sixty years of moisture exposure is devastating to untreated mild steel. Minor surface rust can be treated with rust converter and sealed. Perforated panels must be cut out and replaced. Reproduction floor pan sections are available from early Falcon specialists, though supply is inconsistent. A full floor pan replacement is a major undertaking, budget $2,000-6,000 depending on extent.

Question 2

Sill (Rocker Panel) Rot

Accepted Answer

Bubbling paint along the lower body sides, soft metal when prodded, visible perforation. The sills are enclosed box sections. Water enters through door drain holes, condenses inside the box, and has nowhere to go. The sills rot from the inside out, so by the time you see exterior evidence, the internal damage is extensive. Cut out the damaged sections and weld in new metal. Reproduction sill sections are available. This is skilled panel work, not a DIY job for most owners. Budget $1,500-3,000 per side for a proper repair.

Question 3

Boot Floor and Spare Tyre Well

Accepted Answer

Rust in the boot floor, water pooling in the spare tyre well, perforation around the tail-light mounting points. Tail-light gaskets perish and admit water. The boot lid seal deteriorates. Water collects in the spare tyre well, which has no drain, and sits against bare metal. The boot floor is one of the first areas to rust on early Falcons. Repair sections are available. Lift the boot mat on any car you're inspecting and check meticulously. Budget $800-1,500 for a boot floor repair.

Question 4

Lower Quarter Panels

Accepted Answer

Bubbling, blistering, or perforation on the lower rear quarter panels behind the rear wheels. Road spray and mud collect between the inner and outer skins. The trapped moisture causes rust from the inside, invisible until it perforates the outer skin. Cut and weld repair sections. On XP Hardtops, quarter panel repair is particularly expensive due to the complex body shape. Budget $1,000-2,500 per side.

Question 5

Cooling System Inadequacy

Accepted Answer

Temperature gauge climbs in slow traffic, on hot days, or when towing. The engine may boil over, pushing coolant out of the overflow. The original cooling system was designed for 1960s driving conditions, predominantly open-road cruising. Australian summer temperatures combined with modern stop-start traffic overwhelm the system. A 60-year-old radiator is almost certainly partially blocked. The engine-driven fan only moves adequate air at highway rpm. Have the radiator recored ($300-600) or fit an aluminium replacement ($400-800). Install an electric thermo fan for low-speed cooling. Replace the thermostat (they're cheap and old ones stick). Ensure the water pump is not cavitating or leaking. Flush the entire cooling system.

Question 6

Worn Valve Guides

Accepted Answer

Blue smoke on startup that clears after a few minutes. Increased oil consumption. In severe cases, blue smoke under all conditions. The valve guides wear over decades of use, allowing the valve stems to rock in the guides. Oil runs down the stems and into the combustion chamber, where it burns as blue smoke. The cylinder head needs to be removed and the valve guides replaced or reamed and fitted with oversize-stem valves. This is a machine shop job. Budget $600-1,200 for a complete head recondition including guides, valves, seats, and springs.

Question 7

Crankshaft Rear Main Seal Leak

Accepted Answer

Oil leak from the rear of the engine, dripping onto the bellhousing and gearbox. Oil on the clutch causes slipping (manual cars) or contaminates the torque converter (automatics). The rear main seal is a rope-type seal on the 144ci and 170ci engines. These seals harden and shrink with age, losing their ability to seal against the crankshaft. Heat cycles accelerate deterioration. The gearbox must be removed to access the rear main seal. It's a labour-intensive job but the seal itself is inexpensive ($20-40). While the gearbox is out, replace the clutch (manual cars) as a matter of course. Budget $600-1,200 for the job at a workshop, less if you do it yourself.

Question 8

Fuel System Deterioration

Accepted Answer

Hard starting, rough idle, hesitation on acceleration, flooding, poor fuel economy, fuel smell. The Autolite single-barrel carburettor deteriorates internally, needle valve, float, accelerator pump, and gaskets all degrade. Ethanol in modern fuel attacks old rubber seals and accelerates corrosion of zinc and aluminium components. The mechanical fuel pump's diaphragm perishes. Rebuild the carburettor with a kit if available ($40-80). Alternatively, convert to a Weber 32/36 DGAV, which bolts on with an adapter and provides much better drivability ($350-500 complete). Replace the fuel pump diaphragm or fit an electric fuel pump near the tank with a pressure regulator. Replace all rubber fuel lines, modern ethanol-resistant hose is essential.

Question 9

Fordomatic 2-Speed Automatic: Slipping and Harsh Shifts

Accepted Answer

Delayed engagement when selecting drive or reverse. Slipping under load (engine revs rise without corresponding acceleration). Harsh or clunking shifts between the two gears. The Fordomatic is a 1950s design with friction bands and clutch packs that wear over time. The fluid breaks down, the seals harden, and the internal components wear. Many of these transmissions have not been rebuilt in decades. A full rebuild by a transmission specialist. The challenge is finding someone who still works on Fordomatics, they're not common in Australia. Budget $1,500-3,000. Some owners convert to a later C4 three-speed automatic, which is a bolt-in replacement with much better performance and easier parts availability.

Question 10

3-Speed Manual: Second Gear Synchro Wear

Accepted Answer

Grinding or crunching when shifting into second, particularly on quick shifts or cold gearbox. May refuse to engage second cleanly. Second gear synchro is the hardest-worked component in the gearbox. After 60 years, even a lightly-used gearbox will have synchro wear. Heavy-handed shifting accelerates the damage. Gearbox rebuild with new synchro rings. Budget $800-1,500. Double-clutching on downshifts extends synchro life and is a good habit to develop.

Question 11

Column Shift Linkage Slop

Accepted Answer

The column-mounted gear lever feels vague, won't select gears precisely, or pops out of gear. The column shift mechanism uses rods, bushings, and pivot points that wear over decades. Bushing wear introduces slop, making accurate gear selection difficult. Replace worn bushings and adjust the linkage. Bushing kits are available from US Falcon suppliers. Budget $100-300 for parts and a Saturday afternoon. Some owners convert to a floor shift, which requires a conversion kit and tunnel modification but provides far more positive shifting.

Question 12

6-Volt to 12-Volt Considerations

Accepted Answer

Dim headlights, slow cranking, inability to run modern accessories, difficulty finding replacement bulbs and components. The XK and early XL models used a 6-volt positive-earth electrical system. Six-volt components, bulbs, starter motors, generators, are increasingly difficult to source. The 6V system provides marginal starting performance, particularly in cold weather, and cannot support modern accessories like electric fans, driving lights, or audio systems. Many owners have converted their XK/early XL cars to 12-volt negative earth. This requires a new alternator (or 12V generator), 12V coil, 12V starter motor, 12V globes throughout, a 12V battery, and reversing the ammeter connections. The conversion is well-documented in the Falcon community and costs $300-600 in parts. It's one of the most worthwhile upgrades you can make to an early Falcon.

Question 13

Corroded Wiring and Failed Earths

Accepted Answer

Intermittent electrical faults: lights flickering, instruments dropping out, indicators not cancelling, horn intermittent, starter motor sluggish. Original cloth-insulated wiring deteriorates over 60 years. The insulation becomes brittle, cracks, and falls away, exposing bare wire. Earth connections corrode, increasing resistance. Connector terminals oxidise. For isolated faults, trace and repair individual circuits. For widespread issues, a complete rewire is the answer. Reproduction wiring looms are available from US Falcon suppliers and can be adapted for RHD Australian cars. Budget $400-800 for a loom plus a full day's work. Clean and tighten all earth connections as a first step, this alone resolves many intermittent faults.

Question 14

Generator Charging Issues

Accepted Answer

Battery goes flat, ammeter shows discharge while driving, dim lights at idle. Early Falcons (XK, XL) use a generator rather than an alternator. Generators produce less output at low rpm, the brushes and commutator wear, and the external voltage regulator's points corrode. Combined with a 6V system, charging capacity is marginal. Recondition the generator (new brushes, commutator cleanup) or convert to an alternator. An alternator conversion is straightforward and provides dramatically better charging, particularly at idle. Many owners combine the alternator conversion with a 6V-to-12V upgrade.

Question 15

Drum Brake Fade

Accepted Answer

Braking effectiveness decreases during sustained use, descending hills, or repeated stops in traffic. The pedal feels firm but the car doesn't slow down adequately. Drum brakes trap heat. As the drums heat up, the friction coefficient between the lining and drum decreases. This is an inherent limitation of drum brakes, not a fault. Early Falcons have relatively small 9-inch drums, which limits heat dissipation. This is a characteristic of the braking system, not a fixable fault. Ensure the brakes are in perfect condition: properly adjusted, with quality linings, with drums machined true. Plan stops early. Use engine braking on descents. Front disc brake conversion kits are available for XM and XP models and are a worthwhile safety upgrade if the car is driven regularly. Budget $800-1,500 for a disc brake conversion.

Question 16

Leaking Wheel Cylinders

Accepted Answer

Soft or sinking brake pedal. Reduced braking effectiveness. Brake fluid visible on the inside of the drums. The rubber seals in the wheel cylinders harden, crack, and leak with age. This is universal on cars with drum brakes that are more than a few decades old. Replace all four wheel cylinders. If one has failed, the others are close behind. Wheel cylinders are still available ($40-70 each). Flush the entire brake system with fresh DOT 3 fluid. Budget $300-500 for a complete wheel cylinder replacement and system flush.

Question 17

Ball Joint Wear

Accepted Answer

Clunking from the front end over bumps. Vague steering. Uneven front tyre wear. The upper and lower ball joints in the front suspension wear over time, developing play. Australian roads accelerate this wear. Unlike the earlier Holdens that used king pins, the Falcon's ball joints are more modern but still wear predictably. Replace the worn ball joints. Ball joint kits are available from Falcon specialists and US suppliers. Budget $200-400 per side for parts. This is a job that requires a spring compressor or a press, not a casual backyard task.

Question 18

Sagging Rear Leaf Springs

Accepted Answer

The rear of the car sits lower than it should. Bottoming out over bumps. The rear end wallows and bounces. Leaf springs lose their temper over decades. Cars that have been loaded heavily or towed sag faster. Broken individual leaves also reduce spring rate and ride height. Re-temper the springs at a spring specialist ($100-200 per spring) or replace with new springs ($300-600 per pair). While you're at it, replace the rubber bushings in the spring eyes and shackles.

Falcon (XK-XP)

Falcon (XK-XP) known problems