Lets cut straight to the chase. The days of replacing the brake pads on their own or getting your brakes “relined” went out with bell bottom pants and Go-go boots. The average customer does not understand this and is often upset at the cost of a brake replacement repair. The cause for this is a basic misunderstandings of whats the mechanically correct and safe way to carry out this repair.
You can always save a quid by getting weird uncle James to slap a set of pads in your car on the weekend. a product of unknown quality that came off the shelf of a Supercheap auto store and was fitted by a man with an obvious drinking problem on a hot Sunday afternoon. Really, this is your cars brakes and people, are willing to take short cuts?
What should be carried out and what are the costs affiliated.
Brake pads should never be replaced on their own. People will throw stones at me over that comment but lets look at why. Brakes work by clamping a fibrous material using extreme pressure to a metal disc rotor. The result is the brake pads and the disc rotor mate them selves to one another, this is a result of friction and heat which is whats used to slow your car down. That is to say small groves, high and low spots are formed in the disc rotor and the brake pads. By throwing the pad out and putting a new pad directly onto the disc rotor that has not been machined or replaced you are taking a pad that is fresh and adding it to a rotor that already has these groves in them. The results can be noises, poor brake application, rapid pad wear and in extreme cases can cause the pedal to be soft resulting in dangerous breaking. Just replacing pads is dangerous and unethical.
The correct procedure:
The disc rotor should be machined with any pad replacement. This means a minuscule amount of metal is cut off the disc rotor to form a new flat surface onto the rotor. However all rotors do have a minimum thickness. If this minimum thickness is reached before or after the machining process the disc rotor must be replaced. The metal of the rotor is used to dissipate the heat caused by the friction of using the brakes. Once this rotor is below the minimum thickness its ability to dissipate heat is reduced causing major safety risks and in some cases the discs can crack or even explode.
European cars: most european vehicles go below the minimum thickness in one set of brake pads. This is caused by the compound of metal used in most european cars. It gives superior braking results at the cost of the rotor needing replacing almost every time the pads get replaced.
Disc pulsation or brake shudder: This is when the metal disc rotor has wrapped, this is caused by over heating the brakes. It can be fixed by machining the rotor but thats foolish. lets look at why. We already discussed the role the metal rotor has in cooling the brakes down. By machining the rotor you asking to brakes to do the same task with less metal for cooling. The result is the rotor will warp again and will do it sooner this time as there is less metal there to do the job of heat dissipation. Once you have brake shudder, replace the rotor or you will be back in a few weeks complaining that the same fault has happened again.
Brake fluid: brake fluid should be replaced every two years regardless of the milage. Most workshops advise doing this with the brake replacement and we do advise this. More information about brake fluid and the need for it can be found by clicking on the following link.
Why do i need to change my brake fluid?
Cost: The cost to do this job properly depends on a lot of variables. The vehicle involved, the brand of pads used and if the rotors are getting machined or not. Below is the rough guide lines for what it should cost to do this job properly. Obviously new disc rotors on a BMW X5 are more expensive than brakes on a Toyota Yaris.
Pads + machine rotors +labour + brake fluid flush $300-$600 per axle (that is to say front only or rear only)
Pads + new rotors + labour + brake fluid flush $400 -$1200 per axle The main variable in these prices are the cost of the rotors them selves.
Its common knowledge that brakes are one of the more expensive items on the list of things a car may need. However it should be the last thing on the list of things you take short cuts on. If you cant afford to repair your brakes properly, you cant afford to drive a car. Taking shortcuts put you and other road users at risk.