Prevention is cheaper than cure, and it is not close
Van downtime costs UK firms around £1,172 a day. Set that against a £140
battery or a £90 tyre and the argument stops being about mechanics and starts being about
arithmetic. You do not have to predict the exact day a part will fail for early replacement
to be the right call. You only have to be roughly right about the risk.
The short version. Battery and tyres between them are about 31% of all
breakdown call-outs, and both are preventable for under two hundred pounds.
The other two are habits rather than parts. Give a modern diesel a proper run every week
so the DPF can clear itself, and never let the fuel or the AdBlue get down to the warning,
because a quarter of a tank is your margin for the three hour jam you did not see coming.
Cause 1 · about 18% of business breakdown call-outs, the single biggest cause
Replace the battery before it strands you, not after
A commercial van battery is commonly £90 to £200 fitted. One day off the road costs the average UK firm over a thousand pounds in lost work. You do not need to be right about the exact failure date for early replacement to be the correct business decision, you only need to be roughly right about the risk.
What to do
Get it load-tested every year, and again before winter.
Most parts shops do this free in a few minutes. A load test tells you what cranking amps it can still deliver, which is the only honest measure. Age alone is a proxy; the test is the evidence.
Plan on replacing a working-van battery at three to four years, sooner if the test is marginal.
A car battery doing steady motorway miles can see five years or more. A van doing short urban drops, with a tracker, a tail lift, an inverter or a fridge pulling on it, rarely reaches a full state of charge and dies considerably earlier. Judge it on duty cycle, not on the warranty sticker.
If you only do short runs, put a smart charger on it overnight once a week.
Short journeys never fully recharge a battery, and a battery held permanently part-charged sulphates and loses capacity for good. This single habit adds years and costs almost nothing.
Carry a lithium jump pack rather than jump leads.
Leads need a second vehicle, which on a country lane at eleven at night you have not got. A pack good for a 2.5 litre diesel lives in the door pocket and turns the most common breakdown in the country into a five minute inconvenience.
Clean and grease the terminals when you check the oil.
Corroded or loose terminals mimic a dead battery exactly, and people replace perfectly good batteries because of them. It is a two minute job with a wire brush.
Act now if you see these
- It cranks slower than it did, especially on the first start of the day.
- Dash lights dim noticeably while it turns over.
- Stop-start has quietly stopped working. That is often the van protecting a tired battery, and it is an early warning most drivers read as a fault.
- You have needed a jump even once. Treat that as the battery telling you, not a one-off.
- It has sat unused for a fortnight or more.
Where this gets people
Stop-start vans need the right type, and often need it registering
If yours has stop-start it almost certainly wants an AGM or EFB battery, not a standard one, and on many makes the new battery has to be registered or coded to the vehicle. Fit a plain battery, or skip the coding, and the charging system will overcharge and cook it in months. Ask the question before you buy, especially if you are fitting it yourself.
A battery that keeps going flat may not be the battery
Replacing a battery twice in a year means something else is wrong: a failing alternator, or a parasitic drain from an accessory that was not wired through an ignition feed. Tail lifts, trackers and aftermarket alarms are the usual culprits. Get the drain measured rather than buying a third battery.
Cause 2 · about 13% of call-outs, and the single most common reason a van simply stops
Carry spares that are actually usable, and the tools to fit them
Around 180,000 UK call-outs a year are a driver with a flat and no spare. That is a thirty minute job turned into a recovery, a lost day and a let-down customer, purely for want of a wheel in the back. Two spares already mounted on wheels is the single best-value thing a trade van carries.
What to do
Carry spares already mounted on wheels, not loose tyres.
A loose tyre is useless at the roadside because you cannot fit it without a machine. On a wheel it is a twenty minute job. Two of them covers the case that actually ruins days, which is two tyres damaged by the same pothole or kerb strike.
Strap them down properly.
A 25 to 30kg wheel loose in the back is a projectile in a heavy stop, and it will go through a bulkhead. Use a proper ratchet strap to a load-rated anchor point, not a bungee.
Carry a trolley jack rated above your axle weight, not your van weight.
You lift one corner, not the whole van, but do not cut it fine: a two tonne jack is marginal under a loaded 3.5 tonne van. Two and a half to three tonnes gives you the margin, and a low-profile one actually fits under a laden van, which a cheap tall one often will not.
Carry a breaker bar and the right socket.
Van wheel nuts are torqued far higher than car ones, commonly somewhere between 140 and 200Nm depending on the make, and the wheelbrace that came with the van frequently will not shift them. A half inch breaker bar and a deep socket in your size will. Check your handbook for the figure and the socket size, and keep a note of both in the cab.
Carry a torque wrench, and use it.
This is the step everyone skips and it is the one that matters most. Undertightened nuts lose a wheel. Overtightened nuts warp discs and stretch studs so the next person cannot get them off at all. Nipping them up by feel with a breaker bar is how both happen.
Check pressures weekly against the laden figure, and carry a 12V compressor.
Van tyres have a laden and an unladen pressure and they differ a lot. Running laden on unladen pressures destroys sidewalls from the inside and is the main cause of the blowouts people blame on bad luck.
Know your full sidewall marking by heart, or keep a photo of it on your phone.
Something like 215/65 R16C 109/107T. The C and the load index are the bits that get missed, and they are the bits that determine whether a mobile fitter arrives with a tyre that is legal on your van. Reading this out first is the difference between one call-out and two.
Act now if you see these
- Tread anywhere near the 1.6mm legal minimum across the central three quarters. On a van that earns money, replace well before that.
- Uneven wear across the tread, which means pressures, alignment or a worn component rather than mileage.
- Any bulge, split, scuff or kerb damage on a sidewall. That is a replacement, not a repair, whatever the tread looks like.
- A tyre you have been topping up for weeks. It is already damaged inside.
- Cracking or crazing in the rubber, which is age rather than wear.
Where this gets people
Two spares cost you payload
Two mounted van wheels is roughly 50 to 60kg. If you run anywhere near your gross vehicle weight, that is 50 to 60kg of payload you no longer have, and being overweight is an offence with real consequences at a roadside check. Weigh your van loaded before you assume you have the headroom. For a lot of trades the answer is one spare on a wheel, not two.
Spares age out even unused
Rubber degrades whether it turns or not. There is no legal age limit on van tyres the way there is on the front axles of HGVs and coaches, but most manufacturers advise replacement somewhere between six and ten years regardless of tread. Check the four digit code on the sidewall: 2319 means week 23 of 2019. A pristine spare from 2014 is not the asset you think it is.
None of this kit changes the motorway rule
Carrying a jack does not make a hard shoulder safe. Do not change a wheel on a motorway hard shoulder, ever, no matter how quiet it looks or how well equipped you are. The kit is for lay-bys, yards, customer sites and country roads with a proper verge. On a motorway you get behind the barrier and you get recovered.
Never get under a van held up by a jack alone
A jack is for lifting, not for holding. Chock the wheels, use the manufacturer jacking point, leave the van in gear with the handbrake on, and if any part of you is going underneath then axle stands are not optional.
Cause 3 · the characteristic modern van failure, and the one most likely to cost you a whole day
Stop treating the DPF warning as advisory
Claims data puts NOx sensor, AdBlue injector and DPF repairs somewhere between roughly £320 and £900. Caught early, a blocked filter is a forced regeneration at a hundred-odd pounds. Ignored, it is a replacement filter well into four figures, and unlike a battery or a tyre it is not a roadside fix, so it is a day or more off the road either way.
What to do
If the van does mostly short urban drops, give it a deliberate motorway run most weeks.
A DPF burns off its soot during an active regeneration, which generally needs sustained speed around 40mph or more for fifteen to twenty minutes with a reasonable amount of fuel in the tank. A van that never gets that will block, and it is a question of when rather than whether.
Learn what a regeneration feels like, and let it finish.
Raised idle, a hot smell, the cooling fan running hard, sometimes a slight loss of response. Switching the engine off halfway through an attempted regeneration is the most common way drivers block their own filter, because it aborts and the soot load climbs again.
Treat an AdBlue countdown as a hard deadline from the first warning.
The van is legally required to refuse to restart once the countdown expires, and it will. A top-up and a reset is cheap. A crystallised injector or pump because the tank ran dry repeatedly is several hundred pounds.
Buy AdBlue in sealed containers and keep the filler clean.
The system is intolerant of contamination. Decanting from an open drum that has been sat in a yard is a reliable way to kill an injector.
Use the right oil specification.
Low-SAPS oil exists specifically to protect a DPF. Topping up with whatever is on the shelf shortens the filter life measurably, and it is an easy mistake to make in a hurry.
Act now if you see these
- A DPF light, which means act this week rather than at some point.
- Noticeably more frequent regenerations than it used to do.
- Rising fuel consumption with no change in the work.
- Oil level climbing above full, which is diesel getting into the sump from repeated failed regenerations.
- Limp mode, which means the window for a cheap fix has probably already closed.
Where this gets people
Removing a DPF is not an option
Deleting or hollowing a DPF makes the vehicle fail its MOT, which has included a visual DPF check for years, and it is an offence to use a vehicle on the road with its emissions equipment removed. Anyone offering it as a cheap fix is selling you an MOT failure and an insurance problem.
Cause 4 · entirely self-inflicted, entirely avoidable, and far more common than anyone owns up to
Never run either tank down to the warning
These two are different from everything above, because there is no part to replace and nothing wears out. There is only a habit. Both failures are completely within your control, both are embarrassing, and the diesel one can be genuinely expensive rather than merely inconvenient.
What to do
Treat a quarter of a tank as empty, and fill up there.
The gap between a quarter and the warning light is your margin for everything you cannot see coming. A three hour standstill on a motorway. A closure that sends you forty miles round. A station whose pumps are dry, which happens more than you would think. Winter, where you may want the engine running for heat while you wait for recovery. None of that is a problem with a quarter in the tank and all of it is a problem without one.
Remember that sitting still still burns fuel.
A diesel van at idle commonly uses somewhere around half a litre to a litre an hour, and noticeably more with the heater or air conditioning working hard. A long jam will not empty a decent tank on its own, but a long jam on top of a nearly empty one is how people end up stranded in the worst possible place, in a live lane of stationary traffic.
Do not trust the last quarter of the gauge.
Van fuel gauges are rarely linear and the bottom quarter tends to fall away much faster than the top. The range-to-empty readout is also an optimist: it is based on how you have just been driving, so a figure earned on a steady motorway run will not survive a loaded urban drop round.
Keep AdBlue topped up as routine, and never let a countdown start.
The countdown is not a suggestion and it is not a fault. Modern diesels are legally required to stop you restarting once it expires, and they will, wherever you happen to be parked at the time. AdBlue in sealed containers costs very little. Topping up on a forecourt in daylight when it is half full is a two minute job that costs pennies; being refused a restart on a customer site is a day.
Carry a sealed five litres of AdBlue and treat it as untouchable.
Sealed, because contamination is what wrecks injectors. Untouchable, meaning you replace it the moment you use it, rather than discovering the empty container the next time.
If it is an electric van, apply the same rule at 20%.
Same logic, worse consequences. You cannot carry a jerrycan of electricity, charger availability is far less predictable than fuel, and cold weather takes a real bite out of the range the van promised you.
Act now if you see these
- You are regularly filling up with the light already on. That is not efficiency, it is a habit with no margin in it.
- Any AdBlue message at all, even the early polite one. Deal with it that week.
- A range readout you have learned to mentally add miles to.
- A fuel gauge that has ever disagreed with reality. Gauges and senders do fail, and fuel does get taken.
Where this gets people
Running a diesel completely dry is not just inconvenient
On a modern common-rail diesel the fuel also lubricates the high pressure pump, so running the tank genuinely empty risks damaging it, and it can draw air and sediment from the bottom of the tank through the system. At best it needs bleeding or priming before it will restart, which is a call-out rather than a jerrycan. At worst you are into a four figure pump. This is the bit people do not know: with a petrol car running dry is a nuisance, with a diesel van it can be a bill.
Your breakdown policy may not treat running out of fuel as a breakdown
Some will attend and charge you for the fuel, some treat it as misuse rather than a covered failure, and some will take a dim view of it happening twice. Check the wording before you rely on it, because this is one of the few causes where the cover you are paying for may simply not apply.
AdBlue freezes
It starts to freeze around minus eleven degrees. The van heats its own tank, but a spare container left in the back overnight in a hard frost can be a solid block exactly when you want it. Keep the spare in the cab in winter, or accept it needs thawing first.
Only ever put proper AdBlue in it
It has to meet ISO 22241. Not water, not screenwash, not something decanted from an open drum that has been sat in a yard all summer. The system is intolerant of contamination and the repair is several hundred pounds, so the twenty minutes you save is poor value.