One brake isn't fully releasing, so it's rubbing all the time the car is moving. On the roller brake tester it shows as drag on a wheel that should be spinning free. Left alone it destroys pads and discs, eats fuel, and can get hot enough to boil the fluid at that corner.
Wording as it commonly appears on an MOT certificate: “Brake binding”.
What does it mean?
One brake isn't fully releasing, so it's rubbing all the time the car is moving. On the roller brake tester it shows as drag on a wheel that should be spinning free. Left alone it destroys pads and discs, eats fuel, and can get hot enough to boil the fluid at that corner.
How serious is it?
Usually recorded as: Minor, Major. The tester assesses the actual vehicle on the day, so your certificate is what counts.
What normally causes it?
- A seized caliper slide pin — by far the most common cause on UK cars
- A seized caliper piston, often on the rear where the handbrake mechanism lives
- A collapsed flexible hose holding pressure at the caliper
- A rusted or badly adjusted handbrake cable that won't return fully
- Rear drums where the shoes have swollen or the wheel cylinder has stuck
What a mechanic would check
After a short drive I feel each wheel — not the tyre, the wheel rim — and one that's noticeably hotter tells the story. Then I jack it up and spin it by hand. If it frees off when you crack the bleed nipple, the hose or piston is holding pressure; if it's stiff with no pressure in the system, it's mechanical.
What might need replacing
- Caliper slide pins, boots and grease
- A reconditioned caliper
- A flexible brake hose
- A handbrake cable
- Pads and a disc if they've been cooked
Can you still drive it?
A mildly dragging brake will get you home, but the corner gets hot and fuel economy drops. If you can smell hot brake or the wheel is too hot to touch, stop — boiled fluid means a long pedal when you need it most.
Repair cost
Freeing off and re-greasing slides is cheap. A caliper plus the pads and disc it has ruined is a much bigger bill, which is why catching a dragging brake early pays.
Before the retest
Brake work is usually done in axle pairs — pads and discs are replaced on both sides of the same axle so the car pulls up straight on the roller tester. After new pads or discs, drive gently for the first hundred miles or so if you can, because brakes need bedding in before they reach full efficiency. Keep the old parts or the invoice; a tester will not ask for them, but they settle any argument about what was actually replaced.
Retest rules
If the vehicle stays at the test centre for repair and is retested within 10 working days, a partial retest is often free; some items qualify for a free retest if you bring the car back by the end of the next working day. The exact conditions are set out on GOV.UK, so confirm with the test centre before you leave. A major or dangerous failure means the car cannot legally be driven away unless the previous MOT is still valid and nothing dangerous was recorded — check your certificate first.
Related help
More brakes failures · MOT failure decoder · Ask a mechanic about your certificate
This is general guidance from a UK mechanic, not a substitute for a physical inspection. Only the tester who inspected your vehicle can confirm what was recorded and why.