February 2022

BY Mike Duncan, Technician at Longton Test Centre A customer arrived at the garage and said that their brakes were making a scraping and grinding noise. Brakes shouldn’t really make a noise at all and they definitely shouldn’t be scraping or grinding. With brakes you can bet your bottom dollar the worse the noise the worse the issue. Being the only thing that is the stopping force for your vehicle, you don’t want them failing. There can be many factors to noisy brakes. It could be dirt, brake dust, backing plates, faulty callipers, lack of pads or even warped discs. In this instance, the customer had not been proactive enough in getting brake pad inspected and changed, or they had failed to hear the early warning signs. It could even be their usual mechanic had not provided a quick glance at the obviously deteriorating discs and pads, so had not provided a warning. This led to steel- on-steel stopping the car as there simply was not any sacrificial material remaining on the pads. Result; The discs had deep grooves cut into them, and there was a consequential glitter of metal shavings on everything in proximity. As most of us already know, not everything that glitters is gold. Correction In this example the required correction was quite simple or so you would think. The resolution here was to add new brake pads and discs all around, on all four wheels. The pitting and scouring of the old discs meant they were no longer efficient, and even more importantly, no longer safe. The work included a deep clean of the surrounding areas to remove contamination so that the new friction hardware was installed into a clean environment. There was one stumbling block however; A snapped pin. Yes, I know; “Typical.” This vehicle had gone so long without brake maintenance that a pin had rusted so badly in the back of the pad carrier and sheared upon removal with what seemed to be thread-locker from the 1900s. I may be exaggerating a bit but this hadn’t been touched in a long time. 1990s maybe? That’s 30-plus years ago now. Anyway, the result was a lengthy removal and a new set of bolts. Summary To quote the 1990s, all this “…could be avoided if you take a route straight through…” and I can’t remember how the rest goes. Anyway, my point is that not only are pads relatively cheap to replace and maintain, but you can inspect them for your customer with a quick glance. If you have suspicions, take the wheel off and have a closer look. Don’t be fooled just because the outside pad looks good. It doesn’t mean the inside pad isn’t wearing thin. We know pads and discs should be changed at the same time on the same axle. However, just because the front right set up looks good doesn’t mean the passenger side is good too. After the neglect of this vehicle the owner was landed with a much harsher bill to correct the issue at hand as more hardware and labour was required. For more on brakes, turn to our feature on pages 46-47 38 AFTERMARKET FEBRUARY 2022 TECHNICAL www.aftermarketonline.net BRAKE LIFE Aftermarket visited Longton Test Centre last year, and now Mike from the garage offers up a salutary lesson from a recent brake-related job