How to Inspect and Maintain Your Engine Belts and Hoses

Inspect belts and hoses at least twice a year or every 8,000 to 12,000 kilometres. A useful rule of thumb is to check them during every oil change. Either way, regular visual inspections can catch minor issues before they become major ones. 

If you notice any of the following symptoms, check your belts and hoses immediately: 

• squealing or chirping noises 
• overheating 
• power steering or AC failure 
• leaks under the car 
• dashboard warning lights 

Modern engines usually use a serpentine belt, a single, long belt that powers multiple components. Older cars may have separate V-belts for each accessory. Regardless of the type, here’s how to inspect them: 

• Cracks or fraying: Look for visible wear. Small cracks across the ribs of the belt are a sign it’s aging. Frayed edges or glazing (shiny surfaces) indicate slipping and wear. 
• Tension: Press down on the belt with moderate pressure. It should deflect slightly but feel taut. Too loose? It may slip or squeal. Too tight? It could wear out pulleys or bearings. 
• Alignment: Check that the belt is properly seated on the pulleys. Misalignment can lead to uneven wear and noisy operation. 
• Noise: A high-pitched squeal when starting your car or turning on the AC often means the belt is loose or worn. 

Replacing a serpentine belt is a relatively affordable DIY job. Just make sure to follow your vehicle’s belt routing diagram carefully. 

Engine hoses are usually made of flexible rubber and reinforced fabric. Over time, they can become brittle or mushy — and a burst hose can lead to sudden overheating. 

• Cracks, bulges, or blisters: Inspect hoses visually. Surface cracks or bubbles are signs of weakening. Any swelling or soft spots mean the inner lining is breaking down. 
• Leaks or dryness: Run your hand (engine off and cool!) along the hoses. Check for fluid residue, oiliness, or dry, crumbly areas. 
• Connection points: Look at where hoses attach to the radiator, thermostat, or engine block. These are common areas for leaks due to loose clamps or corrosion. 
• Firmness: Squeeze the hose gently. It should feel firm but pliable — not rock-hard or squishy. 

While some DIYers are comfortable changing belts and hoses at home, others prefer to leave it to the pros. Either way, here’s what to keep in mind: 

• Serpentine belts generally last 90,000 to 160,000 km. If you’re nearing that range, it’s worth checking. 
• Coolant hoses can last longer but are often replaced around 150,000 km or every five to seven years, especially if they show signs of wear.
• Always replace hoses and belts as a set if more than one is worn — it saves labour and helps prevent future breakdowns.
• When changing hoses, flush the coolant system if necessary and use new clamps to avoid reusing fatigued hardware. 

• Check coolant regularly: Old or contaminated coolant can break down hose material faster. 
• Avoid over-tightening: Whether it’s the belt or hose clamps, too much pressure can strain rubber and metal connections. 
• Keep an eye on tensioners and pulleys: A new belt won’t last long if a pulley bearing is failing or a tensioner is stuck. 
• Warm up your engine in extreme cold: Sudden temperature changes can stress older rubber components.
  

When it comes to engine reliability, it’s often what looks minor that matters most. A cracked hose or loose belt may seem like small potatoes compared to engine blocks and transmissions, but they’re often the first things to take down your ride. A few minutes of inspection every season, paired with timely replacement, can prevent costly breakdowns and keep your engine humming along smoothly. 

Because under the hood, the little things aren’t so little after all. 

Visit our website to search for belts and hoses that fit your vehicle, or visit the NAPA Auto Parts stores nearest you, where our friendly, knowledgeable staff is ready to help.