Changing a tyre in the dark and the rain

The tyre change itself takes about twelve minutes. Everything that goes badly wrong on a wet verge at night happens in the four minutes before you touch a single nut. So get those four minutes right and the rest is just turning a bar.

Start with the moment you feel it go.

The first ninety seconds

A tyre losing air feels like the car pulling, wallowing or thudding. Don't stamp on the brakes and don't yank the wheel. Grip firmly, lift off the accelerator and let the car slow itself while you look a long way ahead for somewhere to stop.

You're looking for three things, in this order: level ground, hard ground, and space to stand on the side away from traffic. A gateway, a lay-by, a pub car park, a side road fifty metres up. Driving another quarter mile at 20 mph on a flat will cost you a tyre and possibly a wheel rim. It will not cost you your life. Pushing on to a better spot is almost always the right trade.

What you don't want is the crown of a bend, the brow of a hill, a soft grass verge in February, or a narrow lane where a van comes round at speed and finds you crouched by the offside wheel.

Get as far left as you can. If there's a kerb, put the front wheels close to it. Turn the steering so the wheels point away from the road, so that if the worst happens the car doesn't roll into traffic.

If you're on a motorway, don't change it

This one's a hard rule. On a motorway or a fast dual carriageway, get onto the hard shoulder or into an emergency area, put the hazards on, get everyone out of the nearside doors, climb the bank or go behind the barrier, and call for recovery.

Changing a wheel a metre from lorries running at 60 mph in the dark and rain is one of the genuinely dangerous things you can do with a car. The recovery bill is cheaper than the alternative. On a smart motorway with no hard shoulder, that goes double.

Everything below assumes you've found somewhere sane.

Set the scene before you open the boot

Hazards on. Sidelights on, and leave them on. If it's raining hard, leave the engine running for the wipers and lights unless the exhaust is near where you'll be kneeling.

Everybody out of the car, including the dog, and everybody stands behind the car and off the road. Not in the car. A stationary car that gets hit is a bad place to be sitting. Children and passengers go up the bank, behind a fence, into the field gateway. Give one of them the job of watching traffic and shouting if something comes in too close.

Hi-vis vest on before you start, not halfway through. Keep one in the door pocket, not the boot, so you can put it on before you step out.

If you're carrying a warning triangle and you're not on a motorway, set it well back — further than feels necessary, and further still on a bend or over a crest. On motorways, leave the triangle in the boot.

Light the job properly

A phone torch held in your teeth is not lighting. It's the single biggest reason people mangle a wet roadside change.

Keep a head torch in the glovebox. It costs less than a tank of fuel, it puts light exactly where your hands are, and it leaves both hands free. A small lantern or work light that stands on the ground and throws light sideways under the sill is even better, because a head torch alone casts your own shadow into the wheel arch.

Then, before you jack anything, take everything out of the boot you'll need and set it down together: spare, jack, brace, locking wheel nut key, gloves, and the mat or board you'll put the jack on. Nothing worse than getting the car up and discovering the key's in the kitchen drawer.

Break the nuts while the wheel is still on the ground

Handbrake on. Car in first gear, or Park.

Take the wheel trim off if there is one. Then loosen each nut half a turn — anticlockwise — with the wheel still bearing weight. If the wheel is off the ground it just spins and you get nowhere.

Wet nuts and cold hands are why people fail here. Put the brace on horizontally and push down with your foot on the end of the bar, holding the car for balance. Your body weight will shift a nut your arms won't. If it still won't go, a length of steel pipe over the brace gives you more leverage, which is why a lot of people keep one in the boot.

Loosen. Don't remove.

Jacking on wet ground

Find the jacking point. It's a reinforced pad under the sill, usually marked with a notch, an arrow or a triangle in the plastic. The handbook has a diagram. Putting the jack under the sill anywhere else will fold the sill like a drinks can.

On tarmac that's soaked, or on gravel, or on a verge, the jack foot sinks and tilts. That's how cars come off jacks. Carry an offcut of plywood about the size of a hardback book and put the jack on that. A floor mat will not do it.

Raise the car until the flat tyre is clear of the ground by a centimetre or two, and no higher than that.

Never put any part of your body under a car held up by a jack. Not an arm, not a shoulder. If you've got the old wheel off, slide it flat under the sill as a backstop while you work.

The swap

Take the nuts off, keep them in your pocket or a pot so they don't vanish into wet grass. Pull the wheel straight towards you. If it's stuck to the hub with corrosion, put two nuts back on loosely, drop the car until the tyre just touches, and kick the tyre sidewall sharply from behind.

Lift the spare on. Wheels are heavier than they look and they're slippery when wet — use your legs, keep your back straight.

Line up the holes, hand-tighten the nuts in a star pattern, opposite to opposite, never round the circle. Lower the car until the tyre grips, then go round in the same star pattern and tighten properly with the brace. Firm, using your weight, not jumping on it.

Drop the car fully, take the jack out, and give the nuts one last check.

Then the boring part that people skip

Stow the flat, the jack and the brace. Count your tools.

Check the pressure of the spare at the first garage. Space savers usually take a much higher pressure than a normal tyre, and the sticker on the wheel almost always caps you at 50 mph and a limited distance. Obey it. That wheel is a get-you-home item, and the car will handle differently on it.

Then get the nuts torqued to the manufacturer's figure by a tyre shop within a day or two, and get the flat repaired or replaced. A puncture in the tread can often be repaired. Sidewall damage can't.

One more thing, and it's the one that matters most. A lot of newer cars have no spare at all, just a sealant kit and a compressor, and the kit is useless on a sidewall tear. Go and look in your boot tonight. Find out whether you own a spare, whether the jack and brace are actually there, and where your locking wheel nut key lives.

Then do the whole thing once on your driveway on a dry Saturday afternoon, with your son or daughter watching and taking a turn on the brace. Twenty minutes, no traffic, no rain, nobody cold.

That's the practice run. The real one will come at ten past eleven on a Tuesday, and you won't get to pick the weather.