Brake Pad Question

[ganicuss]

I have a sinking suspicion that my 2008 XC70 wasn't actually checked before it was "certified." I brought it in for 50,000 mile check up and a bunch of red flags are popping up for a car that's had 8,000 miles on my watch, post-cert. Things a certification would certainly have spotted.

Anyway, do you think it's possible (assuming normal driving) that I could have worn through 3mm of brake pad in 8K miles? They say I'm at 2mm now, and minimum for certification would have been 5mm.

Any brake pad experts out there? Please help. Thanks!

[XCovlov70]

I have a sinking suspicion that my 2008 XC70 wasn't actually checked before it was "certified." I brought it in for 50,000 mile check up and a bunch of red flags are popping up for a car that's had 8,000 miles on my watch, post-cert. Things a certification would certainly have spotted.

Anyway, do you think it's possible (assuming normal driving) that I could have worn through 3mm of brake pad in 8K miles? They say I'm at 2mm now, and minimum for certification would have been 5mm.

Any brake pad experts out there? Please help. Thanks!

Hi!

While you don't say if it is the Front or Rear pads that are worn out?

Anything is possible as I went through a set of rear pads with 'normal driving' in 42,000 Miles and was GOBSMACKED as it had never happened before!

On every other Volvo I have owned and driven 'normally' the rear pads have lasted twice as long as the fronts, but this time it's the other way around.

I was told that the cause was the EPB (Electronic Parking Brake) combined with the 'sensing' of the car as it seems that when you take your foot off the accelerator (I suspect in your case if you are on the other side of 'The Pond' then you call it the 'Gas Pedal') the brakes are 'charged' which means the pistons push the pads closer to the discs/rotors as it thinks you wish to apply the brakes, which wears out the pads faster!

I guess I will have to see if the next set on the rear go down as fast, while the front pads are now close to 60,000 miles and are not near minimum thickness of pad yet!

[slayer8870]

According to VIDA there is a function like this, but is not part of the EPB:

"Pressurization of Ready Alert Brakes (RAB).
The brake system is pressurized to prepare the brake system for any panic braking.
The system detects the speed at which the driver released the accelerator pedal. If this occurred quickly, the hydraulic unit starts and prefills the brake calipers. This is to eliminate any clearance between the brake pads and discs, which shortens the reaction time of the brake system.
In order for the system to activate, the driver must not have braked and the accelerator pedal must have been released quickly.
"

[XCovlov70]

According to VIDA there is a function like this, but is not part of the EPB:

"Pressurization of Ready Alert Brakes (RAB).
The brake system is pressurized to prepare the brake system for any panic braking.
The system detects the speed at which the driver released the accelerator pedal. If this occurred quickly, the hydraulic unit starts and prefills the brake calipers. This is to eliminate any clearance between the brake pads and discs, which shortens the reaction time of the brake system.
In order for the system to activate, the driver must not have braked and the accelerator pedal must have been released quickly.
"

I would have thought that it should have read......

'In order for the system to NOT activate, the driver must not have braked and the accelerator pedal must not have been released quickly'

Then my Rear Brake Pads should have lasted a hell of a lot longer than 42K otherwise it should be called......
"Pressurisation of Rapid Wear Brakes"

[slayer8870]

also I was looking in vida and especially the BCM and ECB modules and I can't find any controls related to this function, so I guess anytime you somewhat quickly release the gas pedal the system will react...what else you can say - what does it mean "quick"? my quick release of the pedal will be the slowest ever for a racing drive, so I should say they designed it to be activated anytime on a pedal relase

[XCovlov70]

also I was looking in vida and especially the BCM and ECB modules and I can't find any controls related to this function, so I guess anytime you somewhat quickly release the gas pedal the system will react...what else you can say - what does it mean "quick"? my quick release of the pedal will be the slowest ever for a racing drive, so I should say they designed it to be activated anytime on a pedal relase

Sorry 'slayer8870' you lost me with your TLA's (Three Letter Abbreviations). What does BCM & ECB stand for?

I would also like to try and find out if having a manual transmission and using 'Engine Braking' by changing down through the box has this effect on the brakes, but I guess that is a question that I will have to put to the Dealer as Volvo UK Customer Service have lost the ability to answer 'technical questions'!

[slayer8870]

sure - BCM is Break Control Module; ECB should be read EPB (sorry for the typo) and it stands for Electrical Parking Brake. As for the engine braking - i can't tell because we all drive automatic here in NA, but hopefully you can get some knowledgeable tech from the dealer that can give you more insights.

[karlmagnum]

Changing brakes?
when is it the right time to change my brakes and whats up with the sqeakin noise when i step on the brakes does it mean i gota change it?

Sometimes, even new pads will squeak. So your best bet is to have it check. Applying anti-squeal can help sometimes.

[XCovlov70]

sure - BCM is Break Control Module; ECB should be read EPB (sorry for the typo) and it stands for Electrical Parking Brake. As for the engine braking - i can't tell because we all drive automatic here in NA, but hopefully you can get some knowledgeable tech from the dealer that can give you more insights.

Thanks for the clarification on BCM and EPB.

I do intend to drop a question to the dealer asking about engine braking and changing up on a manual box, and will let you know what the reply is.

[XCovlov70]

Here is the response received from the Service Manager at my local dealership regarding Rear Pad Wear......

"The brake pads,
We always see the rear brake pads wearing more than the fronts but ref the brakes pushing out to disc/rotors this only happens when you snap your foot of the acc pedal quickly which thinks you are going to hit the brake pedal."

My accelerator/gas pedal foot just got lighter and slower while the car also slowed down a touch without activating the rear brakes!