Brake failure in commercial vehicles can kill people. That’s not an exaggeration – brake problems cause serious accidents every year. Most of these failures could be prevented with proper maintenance, but too many drivers wait until something goes wrong.
The good news is that brakes usually give you warning signs before they fail completely. You just need to know what to look for and act on it quickly.
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Truck’s Brake System
Most commercial trucks use air brakes, which work differently than the hydraulic brakes in cars. Air brakes use compressed air to push brake shoes against drums or pads against rotors. The main parts include an air compressor, air tanks, brake chambers, and all the lines connecting everything together.
Some trucks have disc brakes up front and drums in the rear, others use drums all around. Newer trucks usually have automatic slack adjusters, but older ones need manual adjustment. Know what type of system you’re working with – it makes a difference when you’re doing maintenance.
Daily Pre-Trip Brake Checks
Federal law requires daily brake inspections, and for good reason. Start by looking at all the brake parts you can see. Check for cracked brake shoes, warped drums, or anything that looks damaged.
Test your air pressure – it should build to at least 100 psi within 45 seconds of starting the engine. Make sure your low air warning comes on below 60 psi. Test your parking brakes by trying to move forward gently with them set.
Check brake adjustment by marking your pushrod and measuring how far it moves when you apply the brakes. Most systems should move 1.5 to 2 inches, but check your manual since this varies.
Listen for air leaks while the brakes are applied. Even small leaks can turn into big problems fast.
Warning Signs of Brake Problems
Your truck will tell you when something’s wrong. Squealing or grinding noises are obvious red flags. But watch for subtler signs too – pulling to one side when braking, needing more pressure on the brake pedal, or a spongy feel.
Hissing sounds mean air leaks. Vibration in the steering wheel or brake pedal usually means warped drums or rotors. Don’t ignore these symptoms – they get worse, not better.
If your stopping distance increases or the brakes fade after repeated use, you’ve got problems that need immediate attention.
Keeping Air Brakes Dry
Water is bad news for air brake systems. It can freeze in cold weather and cause brake failure, plus it causes rust inside your tanks and lines. Drain your air tanks every day, especially when humidity is high or temperatures are changing.
Check your air lines regularly for cracks, wear, or loose connections. Road debris and weather beat these lines up, so they need regular replacement. If you see damage, fix it before it fails.
Cleaning and Inspecting Brake Components
Brake pads and shoes collect dirt and debris that hurt performance. Clean them with brake cleaner during maintenance – never use compressed air because brake dust is dangerous to breathe.
Look for uneven wear patterns that might indicate alignment problems. Measure pad and shoe thickness against specs and replace them before they get too thin. Waiting until they’re worn out damages your drums or rotors.
When you need replacement parts, make sure they’re compatible with your system. Consult with suppliers of heavy duty truck parts who can provide proper specifications and quality components.
Hydraulic System Maintenance
Even air brake systems often have some hydraulic components. Keep brake fluid clean and at proper levels. Old brake fluid absorbs water and causes corrosion or brake fade.
Check hydraulic lines for leaks, cracks, or swelling. These systems are under high pressure, so small problems become big ones quickly.
Stick to Maintenance Schedules
Follow your manufacturer’s maintenance schedule for brake inspections and replacements. Usually that’s every 12,000 to 15,000 miles, but heavy hauling, mountain driving, or city driving means more frequent service.
Keep records of what you’ve done and when. This helps track wear patterns and can save money on warranty claims.
Fix Problems Immediately
When you find brake problems, fix them right away. This isn’t something you can put off. Brake failures happen fast and without much warning.
Small problems like minor air leaks or slightly worn pads turn into major failures quickly. The money you might save by waiting usually costs way more in the end, not counting the safety risks.
Brake maintenance isn’t exciting, but it keeps you alive and saves money. Your brakes work hard every day – give them the attention they need.
Know When to Get Professional Help
Some brake work is beyond what you can do on the road. Major repairs, brake system bleeding, or complex diagnostics need a shop with proper equipment. Don’t try to save money on brake work that’s over your head – it’s not worth the risk.