Largely ignored until problems pop-up, you depend on your tractor trailer air brake system to keep your truck, cargo and fellow roadside passengers safe. But when brakes don’t respond as expected in unusual circumstances, was the panic-inducing incident merely a one-off occurrence? Or is there a potentially more dangerous problem bubbling up?
How to Spot Impending Brake Problems
Brake problems are easily recognized when drivers know what to look for…
- Brake Balance Issues
Aside from brake adjustment issues, which are obvious to even the most green tractor trailer operator, brake balance issues are among the most common brake malfunctions.- Drivability Signs: Each wheel (except the front wheels) should share braking work equally. If your truck pulls distinctly to one side or another when you engage the brakes at high/low speeds, during heavy/light applications, when lightly/heavily loaded, or in specific conditions (such as on wet surfaces), you may have balance issues.
- Obvious Visual Signs: None (assuming the brakes are properly adjusted).
- Potential Causes: A number of problems can cause balance issues: Kinked hoses or blocked valves; Mismatched hoses/fittings between a valve and brake chamber; An odd hose that’s too small/large; Mismatched lining/glazing on the inner surface of a brake drum; An improperly sized actuator chamber/slack adjuster; Even a defect in the brake itself that shows under force.
- Brake Timing Problems
Brake balance and timing are critical to stability. Tractor trailer brakes should release in order, beginning in the rear by only a slight margin, and releasing immediately.- Drivability Signs: The two most common brake timing problems are when brakes hang on a little longer than they should, feeling as if they’re still in force even after your foot’s off the treadle and you’ve applied throttle. And instances where tractor trailer brakes apply first (or with more braking force), resulting in a pushing sensation when you apply the brakes. The latter will cause your rig’s brakes could wear faster at best – or your hauler to be bumped by the trailer at worst, causing dangerous stability problems that could compromise control in the event of a skid.
- Obvious Visual Signs:
- Potential Causes: If brakes are delayed in application or not releasing, there may be a physical obstruction, kink or blockage preventing air from exiting the lines; Twisted/damaged hardware and poor lubrication to cams and bushings can also cause these issues. If your hauler’s brakes are applying first, your trailer valves may have aged or been improperly installed, upsetting application pressure and/or release timing.
How to Report Potential Issues
While most brake problems result in obvious drivability issues, this is not always the case. Some issues are quite difficult to detect without specialized diagnostics. To ensure a safe rig, be sure to be very specific about the details of any braking problems in your next inspection report, including the trailer your rig was paired with during the event, as trailer performance effects hauler performance. This can help your mechanic more quickly resolve potentially dangerous issues while your truck is at the shop.
Not sure what’s stopping your brakes? The professional repair technicians at Ainsworth have the expertise and experience to get you safely back on the road fast. Contact us to schedule a full brake inspection today.
