Brake Fade on a Loaded Descent with Marginal Tyres

This is brake fade. Continuous use on a long descent overheats pads and discs and can boil the fluid; the symptoms match: a pedal that travels further (fluid/heat, possibly a small leak), a hot smell, and pulsing after hard hairpin braking (uneven deposits or a distorted disc). Fade means the pedal you have is not the braking you expect - so stop relying on it.

In the next 400 m:

1. Get off the brakes and onto the engine. Select a lower gear now - second or even first on hairpins - so engine braking holds the car back. Use short, firm brake applications rather than riding the pedal down the hill.
2. Warn the car behind. Hazard lights, and slow progressively rather than braking late for the lay-by.
3. Take the lay-by and stop. Let everything cool with the car in gear and the handbrake on, and do not sit with the foot hard on the pedal (that keeps heat in the pads). Open the bonnet once it has cooled slightly.
4. Never pour water on hot discs or drums - they can crack or distort, and you will turn fade into no brakes.
5. Check after cooling: if the pedal is still long or spongy, or you can see fluid at a wheel or a dropping reservoir, the car is not drivable - call for recovery.

Do not accept the 'it is just the clutch' explanation. A burning smell on a descent with a changing pedal is the braking system until proven otherwise.

Judge each item against what the descent demands.

• Front tyres at 1.6 mm are exactly at the legal minimum. That is a limit for a reason - wet grip and aquaplaning resistance are essentially gone, and on this descent the entire braking force goes through those two contact patches, which are also carrying the engine and most of the load.
• The eight-year-old rear tyre with sidewall cracking is the decisive item. Cracking means the rubber has aged and lost elasticity; tread depth tells you nothing about that. Under a full load, on hot asphalt, on a long descent, that is a sudden-failure risk. Whatever the tread depth, this car is not in a roadworthy condition.
• The load. Four adults, a full boot and a roof box will be at or over the plated maximum for a 2009 estate. Overloading lengthens stopping distances, worsens fade, and the roof box raises the centre of gravity on hairpins.
• The space-saver is an 80 km/h get-you-home tyre with reduced grip and load capacity. It is not a substitute for a loaded car on a mountain road, and it must never be paired with a fully laden descent.

Verdict: it should not continue as loaded. At minimum, the cracked tyre must come off before the car moves again, the load must be reduced or redistributed, and the space-saver used only to reach a tyre shop at low speed. If the brakes are still suspect after cooling, that settles it - recovery, not continuation.

Make the stop slow, visible, and out of the traffic lane.

• Signal and slow early: hazard lights on well before the stopping point, braking gently in good time so the close-following car has time to react - a sudden stop on a descent with someone 10 m behind is how you get rear-ended.
• Use engine braking to slow, with light progressive brake applications, so you are not asking a fading system for a big stop.
• Pull as far right as the road allows and stop with the wheels straight, handbrake on, in gear. Wheels turned into the verge can pull the car off the edge if it rolls.
• Put the warning triangle out only if it is safe to walk. On a descent it goes behind and uphill of the car, far enough back that approaching drivers see it before the bend - not 5 m behind the bumper. If the traffic is fast or the bend is blind, stay in the car with hazards on rather than walking into the lane.
• Get passengers out on the safe side - uphill side of the road, behind the barrier if there is one, and never downhill of the vehicle where a runaway car or a rolling wheel would go.
• Do not stand between your car and the traffic while checking the brakes, and do not put any part of your body under a car held only by a handbrake on a slope.