They squeal and squeak and make shiny rims all dusty, but what do you really know about the only difference between being a driver and a passenger on a downhill run?
Matthew Symons is the Sales Manager for Brake Parts Australia, a Brisbane-based company specialising in, well, brake parts. With nearly 20 years under his brake belt, Symons has seen some big changes — including the day asbestos brake compounds became illegal.
While there was a general societal shift away from asbestos as a common product around the home, when it came to stopping heavy trucks the reality was nothing worked like asbestos, Symons explains: “The users liked the asbestos compounds because they were not as harsh as the new metallic linings that replaced them”.
With a number of manufacturers working to come up with alternatives, Symons says they did a good job in finding a replacement for the outlawed compounds that would gain the acceptance of the transport industry.
“Bendix, for example, issued new compounds as they tried to find one that operators were happy with,” he says.
Along the way the whole industry changed, with most companies now supplying complete linings for virtually the same price it used to cost to re-line the customer’s existing brake shoes.
“I think part of the reason for the change to new linings was the productivity gain it offered operators,” Symons says. “There is less downtime in replacing the linings, compared to waiting for the shoes to be re-lined and refitted.”
Although the majority of modern trucks are fitted with ABS and EBS as standard, Symons says there is no difference in the type of compound used. Yet there are specific compounds formulated for specialty applications.
“For example, a line-haul operator, where the truck spends most of its time in long-distance work, would use a softer compound, where a garage operator needs a compound with high heat tolerance because of the constant stopping with no real rest for the brakes between applications,” he explains.
“But then someone working in a mountainous area, with lots of big climbs and descents, wants a brake compound that is harder than a standard pad, also with high heat tolerance, because of the amount of work they will
do.”
When it comes to brake care and maintenance, Symons says there was a product available in the past called a Safety Check that gave a representation of the amount of compound remaining on a particular lining that could be seen without taking a wheel off and disassembling the brakes.
Speaking on safety, Symons warns that anyone working on or near the brakes should wear a dust mask, and any dust build up should be wiped off with a wet cloth. Air hoses should never be used to blow the dust off.
“Even though we have not had asbestos brake lining for sale in Australia since 2003 all modern brake compounds contain fibres and while they are not asbestos they are still not good for you to inhale,” he says.
Symons doesn’t expect any huge leaps in brake technology, only gradual improvement of existing systems.
“For example, brake shoes for drum brakes still make about 90 percent of our sales, even though disc brakes are becoming more popular as an original equipment item on new trucks,” he says.
“But most trailers still use drum brakes, even new ones, so that is keeping the figure up, however I expect that will gradually change with time as people convert to disc brake technology.”
For more information on Truck brakes visit Brake Parts Australia.