Should Brake Pads be worn out after 8k miles

[ALFAitalia]

Modern brakes wear out FAR faster then back in the 80s and 90s....removing the asbestos doubled there wear rate. Unless you drive very slowly (boringly!) pads won't go past 40 or 50 k these days....and also the discs wear at the same rate....it used to be two or three sets of pads to a set of discs.... quite often they are now replaced at the same time.

 

[Bobby Dazzler]

Our W166 ML/GLE 63 devours the rear pads in as little as 13,500 miles, whereas the W164 ML 63 savours the rear pads over the course of more than 70,000 miles. Similar power, similar weight, similar use, similar brake disc size (albeit different caliper designs). I can only conclude that the compound and thickness are different.

However every GLE/ML we’ve ever had - and there have be a few across all generations - wear the rear pads at a faster rate than the front, including the W163. Even on the W164 ML 63 with the much much much longer pad life, it was the rears which triggered the warning light first but I replaced the discs and pads all round,

As suggested the rear brakes are used to manage speed when cruise control is set, and can be used by ESP to invisibly stabilise the car. The fact that they last so long on the W164 ML 63 is quite remarkable given the car’s weight and performance, especially when you factor in that it towed extensively too in that time.

 

[JHS]

Extremely common misconception. Many modern Volvos are set up to use the rear brakes first, to prevent diving mostly but also because light braking doesn't require load on the front brakes.

Front brakes are bigger yet but when you're braking lightly they barely get used. Same situation with cruise control on. ESC also uses the rear brakes

Regardless of whether the rear brakes come on first, whether they are used in cruise control, whether they are the only brakes used during light braking, rears wearing out before the fronts, never happened in my world, on any car ,ever, on correctly set up brakes.
If you are using up your rear pads in 8k miles then you have a problem.

Our W166 ML/GLE 63 devours the rear pads in as little as 13,500 miles, whereas the W164 ML 63 savours the rear pads over the course of more than 70,000 miles. Similar power, similar weight, similar use, similar brake disc size (albeit different caliper designs). I can only conclude that the compound and thickness are different.

However every GLE/ML we’ve ever had - and there have be a few across all generations - wear the rear pads at a faster rate than the front, including the W163. Even on the W164 ML 63 with the much much much longer pad life, it was the rears which triggered the warning light first but I replaced the discs and pads all round,

As suggested the rear brakes are used to manage speed when cruise control is set, and can be used by ESP to invisibly stabilise the car. The fact that they last so long on the W164 ML 63 is quite remarkable given the car’s weight and performance, especially when you factor in that it towed extensively too in that time.

I can only repeat that if my C Class was chewing up rear pads every 8-10k miles, I would be looking for a problem.

 

[ALFAitalia]

Agree 100 percent. No cars should wear the rears faster......and I've never seen it in nearly 40 years of working on cars. No matter how much the rears are used, anything less than very light use would lock the rear wheels as most of the weight is over the front when braking...and weight transfers further to the front even if only the rear brakes are used. ALFA Giulia models have a bad rep for rear pad and disc wear.....but this was proven to be a case of bad disc brake material and handbrake dragging due to poor early design.
Road cars with front-wheel drive can typically have a brake balance of 80% front-wheel bias, while road cars with rear-wheel drive typically have around 60-70% front-wheel bias.

 

[geoffus]

Agree 100 percent. No cars should wear the rears faster......and I've never seen it in nearly 40 years of working on cars. No matter how much the rears are used, anything less than very light use would lock the rear wheels as most of the weight is over the front when braking...and weight transfers further to the front even if only the rear brakes are used. ALFA Giulia models have a bad rep for rear pad and disc wear.....but this was proven to be a case of bad disc brake material and handbrake dragging due to poor early design.

Exactly, I’ve changed many many fronts, but very few rears.

 

[Bobby Dazzler]

I can only repeat that if my C Class was chewing up rear pads every 8-10k miles, I would be looking for a problem.

The OP posted back to say that another main dealer checked and confirmed that the pads were fine with plenty of life (10mm?) left in them, and that the fault was with the sensor.

 

[Bobby Dazzler]

Road cars with front-wheel drive can typically have a brake balance of 80% front-wheel bias, while road cars with rear-wheel drive typically have around 60-70% front-wheel bias.

When systems apply the brakes - like cruise control or ESP - they choose which brake(s) and how much braking force is applied, and make more use of the rear brakes than a human would traditionally.

Front brakes are used for wiping off speed, whereas rear brakes are used for gentle road speed correction (especially at high speed) or less subtle individual wheel speed in the event of major instability.

If carrying a bit too much speed on your mountain bike, BMX, Grifter, Chopper or racer, then a gentle application of the rear brake resulted in far fewer cuts and bruises than a big squeeze on the front brake.

 

[rf065]

Agree 100 percent. No cars should wear the rears faster......and I've never seen it in nearly 40 years of working on cars.

The brake hold function has changed all that. I've had two sets of pads and one set of discs on the rear of mine, yet the front pads and discs are original ones fitted from factory after 43,000 miles.

 

[JHS]

The OP posted back to say that another main dealer checked and confirmed that the pads were fine with plenty of life (10mm?) left in them, and that the fault was with the sensor.

I know. My comments were directed at raayans.