The degree of trust we place in our vehicles’ braking systems is immense. No matter the road conditions, the speed or the condition of the vehicle, we tend to stand on the brake pedal and expect to come to an abrupt yet controlled stop.
But, as anyone who has ever driven a vintage car will tell you, this hasn’t always been the case – rock-hard pedal pressure, uneven adjustment, wheel lock-up and fade all contribute to long stopping distances requiring an anticipatory driving style. And, as for braking in a bend … thankfully, these days little more than toe pressure elicits rapid, four-square retardation anywhere, in any conditions. But brakes, sadly, do not last forever.
Since the 1930s, hydraulic brakes have usually had some form of dual circuitry, so that in the event of a partial failure, some braking capacity remained. Disc brakes appeared in the 1950s, soon followed by power assistance (features we now take for granted) and today’s almost universal adoption of anti-lock braking systems (ABS) – first used on a passenger car in 1966 – has brought a level of sophistication to the function akin to having an automotive guardian angel monitoring progress, and perhaps creating a comfort zone that can easily be taken for granted.
So what are the warning signs when a braking system is deteriorating? If your vehicle is serviced to a schedule, checking the condition of the discs/drums, pads/linings and callipers/pistons will (or should) be automatic. A simple visual check of the remaining friction material on the pads or linings will give an immediate indication of remaining life, but it will take a trained specialist to estimate the mileage.
Of course, a lot depends on the vehicle’s use and its driver’s braking style, although allowing pads/shoes to wear down to the backing plate will obviously compromise braking ability and likely cause damage to the disc or drum.
Brake component manufacturer ATE advises that if brake-pedal travel begins to increase or the pressure gets ‘soft’, then there could be a failure of one of the circuits or that air has possibly got into the hydraulic system. Only the more expensive vehicles will have electronic brake system (EBS) monitoring that will give an instrument-panel warning when any fault in function is detected. It is also sensible to check the level of fluid in the brake fluid reservoir when the bonnet is open, as when checking your water and oil or topping-up the windscreen-washer bottle. The reservoirs are translucent, with a minimum level mark, and any loss of fluid you notice should be investigated by a brake specialist.
On older cars and those not fitted with ABS, other danger signs to look for can include the front wheels locking up too soon, which usually indicates problems with the rear brakes, such as incorrect brake linings, badly worn or oily linings, worn, warped or damaged discs or drums, or a faulty brake proportioning valve. And if the rear wheels lock up too soon, the same causes apply. If the vehicle wriggles or swerves during braking, especially in emergency situations, then worn, oily or glazed brake linings, faulty callipers or damaged discs or drums could be the cause. In all these cases, driver control is seriously compromised, which could have far-reaching consequences, so it is imperative that the vehicle be taken to a brake specialist for a thorough diagnosis.
But it is not only the pads/linings that wear out – discs and drums also suffer over time, especially if the vehicle is being operated in tough conditions, such as sandy terrain, for extended periods of time. If these components do get scored or scratched, they can, in many cases, be skimmed and re-used but, again, there are limits and advice should be sought from a brake specialist on the viability of this repair. But if the disc or drum is cracked, then it must be replaced. In both cases, the repair or replacement should be done in pairs, ie to both front and/or both rear wheels at the same time.
Defective discs can also signal that there is something other than the braking system at fault. Wheel/tyre balance, a leaking caliper, a worn wheel hub and/or bearing and worn suspension can each manifest themselves by causing a shudder or shimmy when steering, which should be diagnosed at a specialist and corrected without delay.
There is no getting away from the fact that a properly functioning brake system can mean the difference between life and death for you and your passengers, and any sign of a malfunction should be attended to as a matter of urgency. Always ensure, also, that the replacement parts meet the latest legislation.
Brake pads watchdog
While having your vehicle serviced at an authorised dealer will naturally lead to the manufacturer-approved brake components being fitted, having parts replaced at other facilities means you’ll have to rely on the integrity of the facility to use components that conform to South Africa’s legislated quality standards. Brake pads are critical, high-wear components in every modern braking system and currently there are around 105 brands of pads available in the market – most of which are imported.
To help monitor the quality of these pads, the Retail Motor Industry Organisation (RMI) has a forum that deals with the testing and issuing of Letters of Authority (LoA) by the regulator. ‘The information about these matters gets circulated among members without naming and shaming those who are non-members. The test results and reports are forwarded to the regulator to take the appropriate action. Our aim for now is to self-regulate within the RMI membership,’ explains Twala Boco, director of quality and standards at the RMI. So, if you require brake-pad replacement outside of a motor dealership, an RMI-approved facility will offer greater peace of mind.