TECHSTOP 4: The Effect of Weight on a Vehicle – Brake Pad Replacement
WHEN DO BRAKES NEED REPLACING
Answer: When they are worn and no longer as effective as they should be.
Proper brake pad maintenance and inspection is not only critical for the long life of the car, but it can save lives. This is particularly true when it comes to the car’s braking system. Brakes are what enable the car to stop and to avoid accidents. Unfortunately, many drivers overlook brakes when it comes to performing maintenance.
No two cars will obtain the same distance out of a set of brake pads, Why?
- Driver technique, foot on pedal whilst driving
- Bigger than standard wheels and tyres
- Vehicle speed
- Carry varying loads
- Towing caravans or trailers
- Hilly or mountainous regions
- City driving compared (stop-start) with country driving
- Quality of brake products
- Maintenance level of the car
Regardless of the driving habits of the owner, the brakes are a must check item on the car at regular intervals. There is no magic formula when calculating “How Long The Brake Pads Will Last”. You as the technician must ask questions of the owner:
- How long have they been in the car?
- What sort of driving do you do?
- How often do you have the car serviced or checked?
- Do you carry weight?
Do you do much towing, if so what? (Caravan, trailer, Horse float etc.) This is just a sample of what should be asked, this will give you an idea of how to guesstimate how long the current set of pads might last. If in doubt, CHANGE THEM.
The recommended checking period is every 6 months or 20,000kms. If the customer is a bit lax and there might be an extended time period before the car might be seen by a service technician, always make a judgement call on the side of safety and replace the pads. The minimum amount of brake material on a pad is 3mm. When they get down to this level, there is nearly zero heat insulation happening and there is a possibility of further damage that may occur to the caliper. Brake pads can and do wear at different rates for a couple of reasons. If the caliper is a single piston floating type, the slides could be sticking. If it is a solid mount caliper with two or more pistons, there could be a fluid restriction or sticking piston(s).
When Do Brake Pads Require Replacing?
Straight advice, specialists you understand and… It is imperative that when inspecting brake pads for wear, you must have a look at both the inner and outer. If this means removing the caliper because you can’t see one of the pads then so be it.
There is nothing worse than giving a car a clean bill of health, then 2 weeks later the customer comes in with a “Scraping” noise in the front. Guess what, its one of the brake pads down to metal, Why? because you did not check ALL the pads properly.
After the brake check has been completed, it is best to note down an actual pad thickness on the check sheet. Why? Because it makes you look more professional and it is a clearer indication of the rate of wear. So when you ask all the right questions of the customer, you are now better equipped to offer calculated advice on whether or not the pads need changing now or later.
The tool shown in the image to the right is also colour coded, so anything in the RED is a must do now. When in YELLOW, its book the car in before you do too many kilometres or before they go on that road trip. The GREEN is good, we will look at the pads on next service.
Don’t forget the rotors. Have a look at them, measure the thickness, look for the Minimum requirement, do they still meet with O.E. requirements?
If the rotor is 1 to 2mm more than the recommended minimum thickness, but requires machining, it is suggested that the rotor be replaced. The reason being, if the rotor is machined and there is need to remove an amount of material, it may be on the limit when you fit it back to the car. After minimal use there is every chance that rotor will be UNDER the serviceable limit. If something happens, like an accident and the rotors are measured and found to be under, I wonder if the service records will be checked.
Don’t hesitate, always advocate to the client to replace the rotors rather than machine them and state the reasons why.