The Classic Car Breakdown Kit: What to Carry, What to Do, and How to Bodge Your Way Home

Every classic car owner will, at some point, experience the particular character-building exercise of breaking down somewhere inconvenient. Not on a garage forecourt, not outside a helpful friend’s house, but somewhere genuinely awkward: a dual carriageway slip road, a narrow country lane with no passing places, or, with the inevitability that defines the true British classic car experience, a lay-by in the persistent horizontal rain of a traditional British summer. The difference between a mildly entertaining story to tell at the next club meeting and a humiliating four-hour wait for a flatbed lorry is, almost always, preparation. This guide covers what to carry, how to think when it goes wrong, and how to get yourself home using the contents of a modest bag in the boot rather than emptying the contents of your wallet on a recovery truck.

The tools worth carrying

The objective is not a full workshop in the boot. It is the minimum set of tools that covers the maximum number of likely failures without requiring a trailer to transport them. There is a balance to be struck, and it sits considerably closer to the minimal end than most enthusiasts initially assume.

Spanners and sockets

Half-inch AF (across flats) is the single most useful size on a British classic car. It covers the majority of common nuts and bolts on BMC, Triumph, and Leyland-era cars using Unified and BSF fasteners. Nine-sixteenths covers a surprising number of the others. A small imperial AF ring and open-ended set covering roughly a quarter inch to five-eighths will see you through the majority of roadside tasks. Add a basic metric set from eight millimetres to seventeen millimetres for any car with mixed fasteners from the mid-1970s onwards, because British manufacturing began transitioning to metric during that period and most late-classic cars have both systems coexisting in some form.

An adjustable spanner covers the sizes you have not brought and is worth its weight in a breakdown situation. Use it carefully on soft brass fuel union nuts, which round off with such ease that it suggests they were designed specifically for this purpose, and its better to use a correctly sized ring spanner where one is available.

Everything else

• Screwdrivers: A large flat-bladed and a medium crosshead at minimum. Many classic car components, from distributor clamps to carburettor tops, are secured by screws rather than bolts.
• Mole grips and pliers: Mole grips are one of the most versatile roadside tools available. They grip, clamp, turn, and hold things in positions they would rather not be in. Bring them.
• A decent torch: Not the one that has been in the glovebox since 2009 and requires three sets of batteries to produce a glow visible at close range only. A proper LED torch with fresh batteries, ideally a headtorch that allows both hands free when lying on wet tarmac in the dark in August.
• Feeler gauges: For setting points gap if the ignition fails and you carry spare points. Thin, light, and potentially invaluable.
• A jump starter pack: Modern lithium jump starter packs are remarkable devices. They are smaller than a paperback book, weigh very little, live in the boot indefinitely, and will restart a classic car battery that has given up the ghost without requiring a second vehicle or the goodwill of a stranger. Buy one, charge it annually, keep it in the car. The era of flagging down other motorists at nine in the evening is, mercifully, over.
• Tow rope or strap: In case the bodge does not work and you need to be moved somewhere more dignified.
• Cable ties, gaffer tape, and jubilee clips in assorted sizes: The holy trinity of roadside engineering. Between them they can temporarily secure, seal, clamp, or hold together almost anything on a classic car long enough to reach a garage.
• Electrical wire and connectors: A short length of automotive wire, a handful of bullet connectors, and some insulating tape weighs almost nothing and can bridge a failed earth or bypassed switch in minutes.

The spares worth carrying

This is where the classic car owner diverges significantly from the driver of a modern vehicle. A modern car rarely benefits from a handful of spare electrical components in the boot because its electronic systems are either working or they require a diagnostic computer and a main dealer to address. A classic car, by contrast, can frequently be returned to working order by the roadside with a spare set of points, a new condenser, and the ability to set the gap with a feeler gauge. Carry the things that fail.

• Points, condenser, rotor arm, and distributor cap: The complete ignition service kit. If the car has been converted to electronic ignition, the points and condenser are no longer relevant, but the rotor arm and cap remain. Ignition failure is one of the most common causes of a classic car stopping unexpectedly, and having the components to address it immediately transforms a potentially catastrophic breakdown into a twenty-minute inconvenience. Our electronic ignition guide explains why converting to electronic is worth considering precisely to reduce the frequency of these events.
• Two spare spark plugs: Correct grade for your engine, gapped correctly before they go in the boot. A fouled or cracked plug can stop an engine as effectively as any mechanical failure and takes three minutes to replace.
• A fan belt: The correct size for your engine. Fan belt failure stops the engine cooling, charges nothing, and on many classics also drives the water pump. Carry one. They weigh almost nothing and cost very little.
• Spare fuses: The correct ratings for your car. A blown fuse that takes out the fuel pump or the ignition circuit will stop the car as completely as a mechanical failure, and diagnosing it takes longer than fixing it if you have not got a spare fuse of the right rating. A small selection costs pennies.
• Self-amalgamating tape and a length of suitable coolant hose: Self-amalgamating tape applied to a split coolant hose under pressure holds long enough to reach a garage if used correctly and given time to bond properly. A short length of suitable diameter rubber hose cut to fit and secured with jubilee clips is better still. Either is worth more than its weight when steam is emerging from the bonnet.
• A length of fuel hose and two jubilee clips: For a failed fuel line or a perished union. This one has saved more journeys than most owners realise.
• Bulbs: A selection of the common bulb types for your car. Headlamp, sidelamp, brake light. Running without lights after dark is illegal and dangerous, and the fix takes two minutes.
• A litre of engine oil and a small container of coolant: Classics can lose fluids through minor weeps and seeps that are not immediately critical but become serious if ignored over the course of a longer journey. Top up, note the loss, investigate when home.
• WD40: Loosens seized fasteners, displaces water from wet ignition components, and generally improves the situation in more ways than one expects for an aerosol. Never leave home without it.

When it stops: think before you prod

The instinct when a classic car stops unexpectedly is to open the bonnet and look at the engine with the vague hope that something obvious will present itself. Sometimes it does. More often, the engine looks exactly as it always does, which is to say old and slightly oily, and no useful information is obtained. A more productive approach is to think for sixty seconds before touching anything.

The vast majority of classic car breakdowns fall into four categories. Knowing which category you are in directs your investigation immediately.

• Won’t start: Either no fuel reaching the engine, no spark, or a mechanical failure preventing compression. Check fuel level first (not a joke, it happens). Then check for spark by removing a plug lead and holding it near earth while cranking. Then check for fuel by listening for the carburettor flooding on choke or lifting the piston on an SU. A methodical check takes five minutes and almost always identifies the problem.
• Starts but won’t run properly: Misfiring, flat spots, or sudden loss of power usually points to ignition. Wet weather and a sudden misfire points almost immediately to the distributor cap or HT leads. Check them first, after that… check your fuel pump.
• Overheating: The temperature gauge is trying to tell you something important. Stop promptly, do not remove the radiator cap while the engine is hot (a lesson some people learn only once), and allow the engine to cool before investigating.
• Something is leaking: Identify what and where before concluding anything. Oil is dark brown to black and viscous. Coolant is usually green, blue, or orange and smells slightly sweet. Fuel smells exactly as you would expect fuel to smell, which is the prompt to stop the engine immediately and not start it again until the source has been identified and addressed.

The roadside bodges that actually work

Split or burst coolant hose

Allow the engine to cool completely. This takes longer than seems reasonable. Dry the hose surface as thoroughly as possible, then wrap self-amalgamating tape tightly from two inches below the split to two inches above it, stretching the tape as you apply it so it bonds to itself under tension. Apply at least three layers. Allow it to set for ten minutes before refilling the cooling system with water (not cold water into a hot engine) and starting. Drive carefully, keep an eye on the temperature gauge, stop regularly to check, and get the hose replaced properly as soon as possible. This is a bodge, not a repair.

Fan belt failure

If you have a spare belt, fitting it by the roadside is straightforward on most classic cars: slacken the alternator or dynamo mounting bolts, route the new belt over the pulleys, tension by levering the alternator outward, and retighten. If you do not have a spare belt, the folk wisdom suggests a nylon stocking can be pressed into service as an emergency substitute, knotted tightly around the pulleys and capable of providing enough drive to get the car a few miles. Whether this works in practice depends on the car, the diameter of the pulleys, the quality of the knot, and, frankly, a certain amount of goodwill from the universe. Whether a pair of modern yoga pants or leggings performs the same function is a question that has not been formally tested to our knowledge, though the physics of a knotted waistband around a crankshaft pulley at three thousand rpm seems, on reflection, optimistic. The correct answer remains: carry a spare belt.

Points failure

If the car has stopped suddenly with no warning and no obvious cause, and it will not restart, check the points. Remove the distributor cap, observe the points, and look for burning, pitting, or a gap that has closed completely due to a failed rubbing block. If you have a spare set and feeler gauges in the boot, fitting new points takes around fifteen minutes by the roadside and returns the car to running condition. Our ignition timing guide covers setting the dwell angle and timing correctly, which should be rechecked properly once home.

Flooded carburettor

The classic symptom is an engine that cranks willingly, smells strongly of petrol, and absolutely refuses to fire. Hold the throttle fully open while cranking to allow maximum air through and clear the excess fuel. On most classic carburettors this works within thirty seconds of continuous cranking. If it does not, the needle valve in the float chamber may have failed or stuck open, which requires more attention. Remove the float chamber, check the needle valve is seating correctly, and clean any debris from the seat. The fuel should stop flowing when the float rises to the correct level.

Electrical failure and the failed earth

A significant proportion of classic car electrical failures are not failures of the component itself but failures of the earth connection. British classic cars, particularly those wired by Lucas during their more creative periods, rely on earthing through the bodyshell, and those earth connections corrode, loosen, and fail with considerable predictability. If an electrical component has stopped working for no obvious reason, check its earth connection before suspecting the component itself. A wire run directly from the component casing to a clean metal point on the body, secured with a crimp connector, bypasses the failed earth immediately and often restores the component to full function. This applies to fuel pumps, lighting circuits, and ignition components with equal frequency.

Overheating with no obvious leak

If the temperature gauge climbs and there is no visible external leak, suspect a blocked radiator, a failed thermostat, or, on BMC-engined cars specifically, a head gasket beginning to fail. The tell-tale signs of a head gasket are coolant that appears milky or oily, white smoke from the exhaust, or coolant that bubbles in the header tank. If head gasket failure is suspected, do not continue driving. The repair is expensive enough already without further heat cycles compounding the damage. Get the car recovered rather than attempting to nurse it home.

Marque-specific known issues and what to carry

Some classics have characteristic failure modes that are so well documented by their owner communities that knowing them in advance is simply sensible preparation. The table below covers the most common roadside issues on popular British classics, and what to specifically carry for each.

Breakdown cover: sort it before you leave

All of the above notwithstanding, there are failures that cannot be addressed by the roadside regardless of what you are carrying: a broken driveshaft, a seized engine, a snapped timing chain. For these, breakdown cover is the only answer, and standard breakdown policies from mainstream providers are frequently inadequate for classic cars. Many mainstream policies exclude vehicles over a certain age, restrict recovery distance, or apply conditions that effectively make them useless for a car returning from a club event three counties away.

Specialist classic car breakdown cover from providers including the AA Classic, Green Flag, and the cover often included within specialist insurance policies from Footman James and similar is considerably better suited to the reality of classic car ownership. Check the policy specifically for: age restrictions on the vehicle, recovery distance, whether roadside repair is included, and whether the policy covers the car at shows and events as well as on normal roads. Our classic car insurance guide covers what to look for in a specialist policy including the breakdown provisions.

One practical addition: save the breakdown cover number in your phone under a name you will recognise instantly under stress. Searching through a paper document in the rain while standing on a grass verge at dusk is not the moment to discover that the policy document is at home on the kitchen table.

The glovebox checklist

A summary for printing, laminating, and keeping in the glovebox alongside the broken bulbs you were fairly certain you threw away, and the boiled sweets that may very well be as old as the car.

The classic car that breaks down is not a failure. It is, as any experienced enthusiast will confirm, an entirely normal part of the experience and occasionally the best story from the whole trip. The classic car that breaks down and cannot be recovered because nobody thought to bring a spare set of points and a roll of self-amalgamating tape is merely an expensive inconvenience. The difference is a bag in the boot that costs less than a decent lunch and weighs about the same. Our springtime safety check guide covers the pre-season inspection that reduces the chance of any of the above happening in the first place, and our battery guide covers keeping the electrics in the condition they need to be before you leave the driveway.