Expert advice: top five summer breakdowns

Low oil pressure is a common cause of breakdowns (Picture © Mobil 1)

The nature of breakdowns changes between winter and summer. In the winter we’re called out to faults that tend to be relatively easy to find and fix. In the summer, faults are more serious because the heat tends to place more stress on critical components.

Here are five of the typical faults we see in hot weather.

Summer breakdown cause 1: The water leak

Drivers will think it’s OK that they have to top up their coolant every now and again because they can’t see a leak. But in hot weather the car demands more from its cooling system which can expose weaknesses. Before you know it, a slight weep from a failed seal can become a full-on leak.” Possible result: Overheating

Summer breakdown cause 2: Low oil pressure

The hotter the weather, the harder the oil has to work in an engine. But the higher temperatures get, the less viscous oil becomes. This means that instead of the nice gloopy substance that sticks to all moving metal parts to lubricate them, it becomes more like water. If the oil isn’t lubricating properly there is increased wear on all the heavy duty mechanical components like the crankshaft and camshafts. Possible result: Catastrophic engine failure

Summer breakdown cause 3: Rubber belt failure

The alternator keeps the battery that powers the lights, windscreen wipers and sound system, among other things, charged. It’s driven by a rubber belt off the engine and that belt frequently drives the water pump and the air-conditioning too. The hotter the weather, the harder these have to work and if the rubber belt is perished it will eventually snap. That means there’ll be no cooling system and no charge in the battery. Possible result: Overheating, flat battery

Breakdowns can be caused by multiple problems (Picture © Mobil 1)

Summer breakdown cause 4: Electronics

In the winter cars get a good soaking; in the summer that all dries out. We go out to faults where the ignition key is in the driver’s hand but the windscreen wipers will be going and the lights will be on. It’ll be down to a failure in the electrical system but frequently the connectors will be hidden away and they’ll be nigh on impossible for the technician to get at. Possible result: A fault that’s hard to fix roadside

Summer breakdown cause 5: Brakes and clutches

The hotter frictional components like clutches and braking systems get, the more likely their surfaces are to change. The consequence is they’ll no longer grip what they’re supposed to and won't work as they're supposed to. The other reason people’s brake systems fail is because their brake fluid has gone beyond its useful life. Possible result: Brake fade

Nick Reid is a fellow of the Institute of the Motor Industry and head of automotive technology at Direct Line Group