Brakes are the one system on a car where people are reluctant to gamble, which is sensible, but it also means a fair number of pads and discs get replaced because of a noise that was never a fault. Knowing which noise is which saves money in one direction and saves you a much bigger bill in the other.

The First Few Stops Squeal And Then Stops

Start with the harmless one, because it is by far the most common. Leave a car out overnight in damp weather and a thin film of surface rust forms on the discs. It is iron, it is bare, and it happens within hours. The first few applications of the brake scrape that film off, which can produce a squeal or a light grinding note, and then it goes away and does not come back until the car has stood again.

If the noise appears on the first couple of stops of the day, clears completely, and the brakes feel entirely normal, that is surface rust. It needs nothing. It gets worse in winter, worse again if the car sits outside on a driveway, and worse still after the roads have been salted.

Squeal That Does Not Go Away

A persistent squeal is a vibration — the pad is chattering against the disc at a frequency you can hear. Several things cause it:

• Brake dust and debris built up in the caliper and between pad and disc. Sometimes a clean and proper re-lubrication of the slides and backing plates is all it takes.
• Glazed pads or discs. Overheat a brake — a long descent, a heavy tow, sustained hard use — and the friction surface can harden and go shiny. A glazed brake squeals and bites less well than it should.
• Cheap pads. Friction material quality varies enormously and some budget pads squeal from the day they are fitted regardless of how carefully the job was done.
• Missing or wrong hardware. Anti-rattle shims, clips and the right grease in the right places are there specifically to stop this. Leave them out and the brake will talk to you.
• Wear indicators. Many pads have a small metal tab that contacts the disc when the material gets low, deliberately making a noise. That is the pad telling you it is nearly done.

A persistent squeal is not usually an emergency, but it does want looking at, because the difference between “needs a clean and some grease” and “the pads are nearly out” is not something you can hear from the driver’s seat.

Judder Through The Pedal Or Steering Wheel

This one feels rather than sounds wrong: a pulsing in the brake pedal, a shudder through the steering wheel, or the whole car nodding as you slow from higher speeds. It is almost always down to the disc surface not being flat or not being an even thickness all the way round.

The usual causes are thickness variation from uneven wear, genuine distortion from severe heat, and — very commonly in this country — corrosion. A car that has stood for weeks develops pitting and heavy rust on the disc face, particularly in the band the pad does not cover, and once the surface is uneven the pad passes over high and low spots on every rotation. That is your pulse.

It gets worse if a car is parked up with the brakes hot and wet, which is why a vehicle laid up over winter often comes back with juddering brakes that were fine when it went away.

Grinding: Stop Driving

A harsh, metallic grinding that is there every time you brake, gets louder with pressure, and does not clear after a few stops means metal is running on metal. The friction material has gone and the pad backing plate — or the rivets in it — is cutting into the disc face.

This is the one to take seriously immediately, for three reasons. Braking performance is significantly reduced, because a steel backing plate is a poor brake. The disc is being destroyed as you drive, turning a pad replacement into pads and discs. And a pad worn that far can break up or fall out of the caliper entirely, at which point that corner has no brake at all.

If a car is grinding, it should not be driven further than it has to be. That is a genuine safety issue rather than a cautious garage upselling you.

Other Noises Worth Knowing

• A rhythmic click or scrape that follows wheel speed rather than braking — often a stone caught between the disc and the shield, sometimes a loose shield fouling. Usually trivial, occasionally not.
• A groan or moan at very low speed, parking or crawling in traffic. Often just friction material characteristics and nothing to fix.
• A smell of hot metal after a drive, plus one wheel much hotter than the others — that is a sticking caliper or a seized slide pin. It ruins fuel economy, destroys a pad and disc quickly, and can get hot enough to be dangerous.
• A handbrake that binds after standing, common on cars with rear drums or cable-operated calipers, especially after they have been parked up wet and salty.

Urgent, Or Can It Wait?

The honest version:

• Get it looked at now: grinding, a pedal that goes soft or sinks, a pedal that needs pumping, braking that pulls hard to one side, a burning smell with one wheel hot, or a brake warning light.
• Get it booked in soon: persistent squeal, judder under braking, brakes that feel less confident than they did, or a car that has been standing for months.
• Leave it alone: the first-few-stops rust squeal on a damp morning, and a bit of groan at parking speed.

Making Brakes Last Longer

Nothing exotic. Use engine braking on long descents instead of riding the brakes, which is the main reason hill-country cars glaze pads. Try not to park up with brakes hot and soaking. Give a car that mostly does short trips an occasional longer run so the discs dry out and clean themselves. And if a car is going to sit for a long period, leave it somewhere dry if you can.

Brakes are one of the jobs that suit being done where the car is. Pads, discs, calipers and fluid can all be dealt with on your driveway as part of our servicing and repair work, and if something turns out to need more than that, it gets booked in with us. If a brake has failed and the car should not be driven, roadside assistance is the better first call, with emergency call-outs when available.

Start with something the industry does not advertise: “interim”, “full” and “major” are trade conventions, not defined standards. Nobody is obliged to include any particular item in any of them. What matters is what is on the schedule, and whether the garage will tell you plainly what that is before they start.

That said, the conventions are reasonably consistent, and they exist for a sensible reason. Some jobs need doing twice as often as others, so bundling everything into one annual visit would mean either doing cheap work too rarely or expensive work too often.

What An Interim Service Covers

An interim — sometimes called a basic or intermediate service — is the short one, usually done between full services or annually on a car that does very few miles.

Typically it includes an engine oil and oil filter change, a check of all levels and top-ups where needed, a visual inspection of brakes, tyres, steering and suspension components, a look at the exhaust, belts and hoses, lights and wipers checked, and a general look over for leaks and anything obviously on its way out.

What it usually does not include is the other filters. Air, fuel and cabin filters normally sit on the full service list, and that is the main practical difference.

What A Full Service Adds

A full service does everything the interim does, plus the items that come round annually or at longer mileages. In broad terms:

• Air filter replaced
• Cabin or pollen filter replaced
• Fuel filter replaced where the schedule calls for it — common on diesels, less so on petrols
• Spark plugs on petrol cars, depending on the type fitted and the interval
• Brakes inspected more thoroughly, including measuring pad and disc wear rather than glancing at them
• Coolant strength and brake fluid condition tested, not just eyeballed
• A wider check of suspension, bushes, driveshaft gaiters, steering joints and exhaust mountings
• Road test, where the point is to feel for things a static check will never find

For most people running a normal car with normal mileage, this is the sensible default. We will say that straight rather than dress it up: unless your car covers very few miles or you know the last full service was recent, a full service once a year is the option that keeps on top of things without paying for work the car does not need yet.

What A Major Service Adds

A major service is a full service with the longer-interval items folded in. Which items those are depends entirely on the car, which is why a major service quoted without reference to your vehicle should make you ask questions. It commonly includes brake fluid renewal, coolant renewal, and depending on the schedule the gearbox oil, differential oil, or transmission fluid on an automatic.

Two things a major service is not: it is not a cambelt change, and it is not an MOT. Timing belts run to their own interval and are a separate job — an important one — and they get priced separately because the work involved varies enormously between engines. Some schedules do line the two up, which is worth knowing when you budget.

Intervals: Mileage And Time Both Count

Every manufacturer publishes an interval expressed two ways — a mileage figure and a time figure, whichever comes first. People remember the mileage and ignore the time, and that is exactly the wrong way round for a lot of cars now.

Oil does not only wear out from miles. It degrades from heat cycling, it gets diluted by fuel and contaminated by combustion by-products, and it collects moisture. On a car doing short trips the engine may barely reach full operating temperature, so the moisture never boils off and the oil ages faster per mile than it would on a car doing motorway runs. Acids build up in oil that is sitting in a cold engine, and those acids attack bearing surfaces whether you are driving or not.

So a car doing 3,000 miles a year still needs an annual oil change. Arguably it needs one more than the high-mileage car does, because those 3,000 miles were probably the hardest kind of use an engine gets. A car parked most of the week and used for a few short journeys is in the demanding category, not the easy one.

Choosing Based On How You Actually Use The Car

Forget the names for a minute and think about the driving:

• High mileage, mostly longer runs. Interim at the halfway point, full annually. You will hit the mileage trigger before the time one, so you will be servicing more than once a year.
• Average mileage, mixed driving. Full service annually. Major when the schedule’s longer-interval items fall due, typically every second or third year.
• Low mileage, short trips. Full service annually regardless of what the odometer says, and pay attention to brake fluid, coolant and corrosion — standing does more damage than driving here.
• Vans and anything that works for a living. Shorter intervals, more often. Load, idling and stop-start town work are hard on oil, brakes and clutches, and downtime costs more than servicing.
• Car that has stood for a long while. Treat it as needing a full service before you rely on it, whatever the last stamp says. Fluids, tyres and brakes all deteriorate standing still.

Why The Record Matters As Much As The Work

A service is worth having done properly and it is worth having written down. A clear history with dates, mileages, what was replaced and the parts used protects the car’s value, helps whoever works on it next, and matters if there is ever a warranty question. Loose receipts in the glovebox are better than nothing, but a proper record is better still.

If you are not sure what is due on your car, tell us the make, model and mileage and we will tell you what the schedule asks for and what we would actually do. Our servicing and repair work is carried out at your home or workplace, and where a job needs more than a mobile setup allows it gets booked in with us instead.