How to change a flat tyre: interactive 3D repair guide

All 13 steps

1. 1Park on a level floor

   Drive slowly into the bay and stop on the level floor, with room to work beside the flat, here the front left. Switch the engine off at once (a running engine fills a garage with fumes) and get everyone out: no one stays in a car while it is up on the jack.

2. 2Handbrake on, in gear or Park

   Pull the handbrake on firmly and leave the car in first gear or reverse (a manual) or in P (an automatic), so the wheels that stay on the floor are held.

3. 3Chock the wheel diagonally opposite

   Wedge a chock against the wheel diagonally opposite the flat, here behind the rear right, so the car cannot roll while one corner is up on the jack.

4. 4Get out the spare and the tools

   Open the boot, lift its floor and take out the spare, the jack, its handle and the wheel brace. Lay the spare flat on the floor just ahead of the flat wheel, and the tools in a row beside the car, with the torque wrench.

5. 5Loosen the nuts on the floor trap

   With the wheel still on the floor, fit the brace on each nut in turn and push the handle down, anticlockwise, until the nut gives. Loosen them only slightly, no more than about a turn: they stay on until the wheel is off the floor. A nut tightened to about 110 Nm often takes about as much to break free: on a 35 cm handle, a push of about 32 kg. Avoid this trap: With the car up, the wheel is held only through the gears, which have some play, or not at all if neither the engine nor the handbrake holds that wheel: it turns with the brace, and pushing harder rocks the car on its narrow jack, which can slip off. Loosen the nuts while the tyre is still on the floor.

6. 6Put the jack under the jacking point trap

   Find the jacking point nearest the flat, just behind the front wheel: the handbook shows it, and the sill marks it, here with two small notches either side of a strengthened strip. Slide the jack in at its lowest on the floor under it, its head’s groove lined up with the strip, and wind it up until the head just meets it. Avoid this trap: The floor of the car is thin sheet steel. A jack set under it, instead of under the strengthened jacking point on the sill, pushes a dent into it and can go through, while the car hardly lifts and may slip off. Only lift at the jacking points the handbook shows.

7. 7Raise the car

   Wind the jack up slowly. The body rises first while the tyre stays on the floor; keep going until the flat is about 3 cm clear, a little more than seems needed, because the spare, pumped up, stands taller than the squashed flat. No higher: a car high on its jack is less steady.

8. 8Take off the nuts and the wheel

   Unscrew the loosened nuts by hand and keep them together where they cannot roll away. Pull the wheel straight off the studs towards you, lay it on its back, face up, and slide it half under the sill just behind the jack: if the jack slipped while the wheel is off, the car would come down on the tyre, not on the floor or on you.

9. 9Lift the spare onto the studs

   Lift the spare up to the hub and turn it until its holes line up with the five studs, then push it on, flat against the hub.

10. 10Run the nuts on by hand trap

    Screw each nut on by hand, clockwise, with its tapered end towards the wheel: the taper sits in the wheel’s tapered holes and centres the wheel on the studs. Run them all on until they touch, without tightening yet. Avoid this trap: A wheel nut has a tapered end that seats in the wheel’s tapered hole and holds the wheel centred. Turned round, its flat face meets only the edge of the hole: the wheel is not held true, the nut never tightens properly, and it can work loose as you drive. Tapered end towards the wheel.

11. 11Lower it, then tighten in a star trap

    Slide the flat back out from under the sill, then lower the jack until the spare just rests on the floor, so the wheel cannot turn. Tighten the nuts with the brace in a star, each to the one across from it rather than the next one round, so the wheel is pulled evenly against the hub. Tightened to about 110 Nm, the five nuts clamp it to the hub with roughly 4 to 5 tonnes each. Avoid this trap: Tightened one after the next round the circle, the first nuts pull one side of the wheel in before the other side is held, so the wheel sits slightly crooked on the hub and the last nuts never clamp it properly. It can wobble and loosen as you drive. Go across, in a star.

12. 12Lower all the way, check the torque

    Lower the car all the way and slide the jack out. With the car’s weight on the wheel, go round the nuts once more in the same star with the torque wrench set to the handbook’s figure (110 Nm here), until it clicks on each.

13. 13Pack up and drive gently

    Put the flat, the jack and the tools back in the boot and take the chock away. On a space-saver keep to its limit, usually 50 mph (80 km/h) and printed on it, have the nuts checked again after about 50 km (30 miles), and have the flat repaired or replaced soon.

What you need

• Spare wheel · a space-saver here; check its pressure
• Jack and its handle · from the car’s kit
• Wheel brace · with a socket that fits the nuts
• Torque wrench · for the last check, set to the handbook’s figure
• Locking wheel nut key · if the car has locking nuts
• Wheel chock · or a pair, for the wheel diagonally opposite
• Gloves · helpful
• The car’s handbook · for its jacking points and nut torque

Questions

Safety

Never put any part of your body under a car held up by its jack: keep the removed wheel under the sill as a backup, and use axle stands for any work under the car. At the roadside, never change a wheel on a motorway or where the traffic passes close: call for help. Use the jacking points and the torque in your car’s handbook.

• Jacks and axle stands: never get under a car, or put a hand or a foot under it, while a jack alone holds it up. Lift it only at its jacking point, on firm, level ground with the wheels chocked, and set it on axle stands rated for its weight for any work under it.
• Car batteries: a lead-acid battery gives off explosive hydrogen. No sparks, flames or smoking near it, eye protection on, and the last jump lead clamped to bare metal away from the battery.
• Hot parts and fumes: brakes, exhausts and engines stay hot long after a drive, and a running engine fills a closed garage with carbon monoxide: let parts cool, and keep the door open.

About this guide

3D Spatial Reconstruction: models are engineered from factual measurements to show the parts, the fixings and the order of the job before you start. Always check the handbook of your own car.

This guide shows a small hatchback of our own design, with a space-saver spare, in a garage bay: on a level floor, out of any traffic, with the car’s own scissor jack and wheel brace, and a torque wrench for the last check. Its figures are general ones: 110 Nm is a common wheel-nut torque for a small car (the handbooks we checked give 107 to 127 Nm for a Kia and 108 to 147 Nm for a Mazda), and its wheels are held by five nuts on M12 × 1.5 studs. Your car’s handbook gives its own jacking points, torque and spare-wheel limits; where it differs from this guide, follow the handbook.

At a roadside more comes first, and it is what keeps people alive: pull well off the road onto firm, level ground, switch on the hazard lights and get everyone out on the side away from the traffic. In the UK, set a warning triangle at least 45 metres (147 feet) behind on the same side of the road, but never on a motorway, where you should not try any repair at all: wait behind the barrier and call for help (Highway Code, rules 276 and 277).

Jack safety: the handbooks say never to put any part of your body under a car held up by its jack, and to use proper vehicle support stands for any work under it. This guide uses the car’s own jack, which lifts one corner just clear of the floor; while the wheel is off, the removed wheel lies half under the sill beside the jack as a backup, as tyre fitters advise, and it is slid out before the car comes down. With a trolley jack and axle stands, set the car on a stand at the point the handbook gives before the wheel comes off.

The push on the brace is worked out from the torque: 110 Nm on a 35 cm handle is 314 N, the weight of about 32 kg. The clamping force, roughly 4 to 5 tonnes a nut, is our estimate for an M12 nut tightened to 110 Nm. About 30 minutes is Goodyear’s figure for the whole job with the kit at hand.

Sources: UK Highway Code, rules 275 to 278 (breakdowns, motorways), The AA: how to change a flat tyre, Kia owner’s manual: changing tires (chocks, loosening, jack safety, 79–94 lbf·ft), Kia owner’s manual: the compact spare (50 mph, 60 psi), Mazda CX-30 owner’s manual: removing a flat tyre, Mazda CX-30 owner’s manual: mounting the spare (108–147 N·m), Les Schwab: how to change a tire (the flat behind the jack, under the car), Continental: retorquing wheels after about 50 km, Goodyear: changing a flat tyre (about 30 minutes).

The 3D models, drawings and text are our own. The car shown is a generic one of our own design, not any one maker’s model.