The belts and hoses on your car, which can be some of the cheapest and simplest parts on your car, can also be the most critical.

Because they keep your engine and all its accessories running, a breakdown of a belt or hose can easily leave you stranded at the worst possible time. Worse yet, they can often lead to costly damage to your car’s engine or other more expensive parts.

Because they’re so critical to the life of your car, it’s important to regularly check the belts and hoses under your hood to make sure they’re in great condition. Many of these parts cost just a few dollars and can actually prevent thousands of dollars in damage that might occur when they break.

Here are things to look for.

• OWNER’S MANUAL: Always check your owner’s manual for the recommended life of belts and hoses under the hood. Even if they appear like they’re in good shape, belts and hoses often fail starting with their insides — the places you just can’t see. Follow the schedule in your owner’s manual, and always assume a service has not been performed unless you have the records proving it has been.
• HOSES: Every time you have your oil changed (generally every 3,000 miles), make sure you check the condition of your hoses. They should feel moderately soft when you pinch them. If they feel hard and brittle or soft and squishy, they need to be changed before they break. You should also look for any visual signs of wear, such as blistering, cracks or any obvious damage.
• DRIVE BELTS: Have the tightness and condition of all the belts under your hood checked. Many cars use a single serpentine belt to turn all kinds of devices, from the power steering to the alternator, air conditioning compressor and water pump. A serpentine belt failure will bring your car to a total halt, so don’t let it get too worn out. It’s far too risky.
• TIMING BELTS: If your car has a timing belt, follow the replacement schedule precisely, even if it feels like it’s in good shape. Timing belt failure can cause serious, expensive engine damage on most cars. You can avoid thousands of dollars in repairs by having the timing belt changed on schedule, which is typically every 60,000 to 90,000 miles depending on the vehicle.