Squealing or grinding brakes are first of all a safety warning, not just a noise. If you have some experience with cars, you can clean the brakes without a full workshop: a jack, a wheel brace and basic tools are usually enough.
While you are at it, you can inspect the pads and discs and see whether they need replacing. After a Ukrainian winter of grit and road salt this clean is especially worthwhile, as dirt and rust in the caliper slides often cause squealing and uneven wear.
What you will need
Important: Pads, discs and braking surfaces must be perfectly clean: no lubricant, oil or WD-40 on them. Never work under a car supported only by a jack. If you are not confident, leave brake work to a garage.
Step 1
Locate the noise
To avoid stripping all four wheels, first find where the sound comes from. It is easiest with a helper: drive slowly alongside a wall or fence that reflects sound well and listen for which wheel is squealing.
Once you know the wheel, park on level ground, apply the handbrake, jack up that side and put an axle stand in place.
Step 2
Remove the wheel and strip the caliper
If the wheel or caliper bolts are rusted, apply WD-40 Specialist Penetrant, wait a few minutes and only then undo them. Remove the wheel to expose the disc and the caliper with its pads.
Give the caliper a rough clean with a wire brush, taking care if it is painted. Undo the caliper bolts, note how the parts sit and remove the pads.
Step 3
Inspect the pads and discs
Check the pads and disc for deep grooves from stones and other obvious marks. Measure their thickness against the manufacturer's minimum. If pads or disc are worn, cleaning is pointless and they need replacing.
Light surface rust on a disc after the car has stood for a while is usually harmless and wears off under braking.
Step 4
Remove brake dust and burrs
Brake dust builds up where the pads slide into the caliper bracket. Clean it out with a small brush. If a pad that is otherwise fine has a burr on its edge, carefully file off just the burr without touching the friction surface.
Step 5
Degrease and check the moving parts
Spray brake cleaner onto the dirty parts, let it work and drain off. It dissolves grease and evaporates without residue. This is the only way to clean the disc.
Check that the caliper slides and other moving parts move freely. External handbrake pivots, linkages and fastener threads can be treated with WD-40 Multi-Use, spraying precisely while covering the disc and pads with a rag. Wipe off any excess straight away.
Step 6
Reassemble and test
Reassemble in reverse order: pads into the caliper, caliper onto the bracket, bolts tightened to the manufacturer's torque. Check everything once more before refitting the wheel and lowering the car.
Pump the brake pedal several times while stationary so the piston meets the pads. Then test the brakes at low speed on a quiet stretch of road.
Tip: If a wheel was stuck to the hub, clean the hub mating face with a wire brush once it is off and apply a light coat of
WD-40 Multi-Use, keeping it well away from the disc. The wheel will come off more easily next winter.
What next
Inspect your brakes at every seasonal tyre change, in autumn and spring. Keep WD-40 Specialist Penetrant in the garage for seized bolts and nuts, and WD-40 Multi-Use to protect threads from moisture and salt.
These uses come from the experience of WD-40 users in many countries. Always follow the instructions and warnings on the product label.
More guides in «How to use».