Change Car Accessory Belt Kit
The auxiliary drive belt turns the alternator, the air-conditioning compressor, the power-steering pump and sometimes the water pump. If it snaps, the engine loses these essential ancillaries, and it can cause overheating if the water pump is among them.
Do not drive without the belt
If the belt breaks while driving, the alternator stops charging the battery and the charge warning light comes on. If the water pump is on the same belt, the engine overheats within minutes. Stop immediately.
How does the auxiliary belt work?
Driven by the crankshaft pulley, the flat ribbed belt transmits power to the engine's ancillaries. If it breaks, and if the water pump is driven by this belt, stop immediately to avoid overheating the engine.
When should you change the auxiliary belt?
Follow your vehicle's service schedule: the interval varies from 60,000 to 240,000 km depending on the engine. Check its condition at every service: replace it as soon as it shows cracking, fraying or splits.
What to change at the same time
The pulleys
The tensioner and the idler pulley(s) should generally be changed at the same time as the belt. Some manufacturers recommend changing them every other belt replacement.
The water pump
If the water pump is driven by the auxiliary belt, take the chance to replace it during the job. The extra parts are inexpensive compared with the cost of the labour.
Difficulty 2/5
Technically accessible with a torque wrench. On a transverse engine you sometimes have to remove the front right wheel and the engine mount.
Kit price
A full kit costs between £40 and £200 from a motor factor. Average garage price: around £150 for the kit, excluding labour.
Types of auxiliary belt
Ribbed belt (Poly-V)
The most common on modern vehicles. Recognisable by its lengthwise ribs that give good grip. Flexible, quiet and hard-wearing.
V-belt
Still found on some older vehicles. A V-shaped section, less efficient than the Poly-V. Replacement is identical.
