Intermittent scraping noise on braking

[Capri to ST]

As the title says, sometimes when I'm braking, I hear a somewhat faint scraping sound, it's not there all the time. I know some cars have an audible warning designed into the system so that when new brake pads are needed you will hear that warning and can hopefully replace them before they have ground the rotors down. Does anyone know whether our cars have such a warning built into them, and whether hearing a scraping noise means that you made need new brake pads (or rotors)? Thanks all.
The car has 23,000 miles on it, and still has the OEM more aggressive brake pad option which came with the summer tire option. The car hasn't been tracked, and I don't use the brakes super hard on the street, but I know that the brake pads are used for the electronic torque vectoring system so may wear out sooner than you might expect.

 

[SteveS]

If it's on damp mornings when you start from being parked outside overnight, it might just be rust on the rotors, which will go away after a firm brake application or two.

 

[Capri to ST]

If it's on damp mornings when you start from being parked outside overnight, it might just be rust on the rotors, which will go away after a firm brake application or two.

Thanks for the comment, that's an interesting possibility. It was dry this morning and the car is parked in a garage, although the garage has some openings on the side, so it's possible that there's rust there but probably not likely. I'll take a good look at the rotors next morning before I drive the car.

 

[WannabeST]

Miles are irrelevant to brake pads in my opinion, someone with 50k miles of only freeway miles will see less wear than 10k miles of red light green light traffic. With that being said, almost all brake pads have a little warning indicator when the brakes are running down ( I personally take this off before install because I hate the noise).
There is a couple possibilities here:
Your pads are running low and its the indicator
Your rotors are cracked or warped (Unlikely given no tracking)
A rock or debris is stuck on the brake pad or caliper (More common than you think)
Caliper isn't lubricated on the slide pin (Unlikely for your miles)
Cracked/broken/ missing brake pad clip (possible but unlikely if on oem pads)
etc.
The easy solution here in my opinion is grab a bottle of brake cleaner, jack up the car and take the wheel off to inspect the brake pads. If you see the pad is down to the indicator then you have an easy answer - you can remove the indicator to avoid noise but pads should be addressed in the near future. If there is no indicator I would bet there is debris. Spray all the brake components with brake clean like you are baptizing it (everywhere there is contact or sliding) and then put it back together to check/

 

[Magnetic]

When mine started doing that it was just before the brakes were shot. It was intermittent for me to so I'm guessing its time for brakes.

 

[Sprinkle_Star]

Check the amount of friction material you have left on both the inner and outer pads.

I had a scraping noise, and when I was doing my brake job, I took note that the inner pads wore out before the outer pads probably due to my lack of maintenance on the slider pins. Live & learn

 

[Sam4]

Is this not classic dryed-out caliper slider pin syndrome?

 

[WannabeST]

Is this not classic dryed-out caliper slider pin syndrome?

I doubt it because the miles are so low, but it is a possibility.

 

[Capri to ST]

I went by an independent shop that I trust (I'm a pretty bad mechanic), I've been dealing with them for a long time, and one of the guys said that one of the inside front brake pads was almost gone, and the other inside front one was pretty close. I did need front brakes, thanks for the helpful answers.

 

[WannabeST]

Glad you found the issue, I would ask them if they lubed the slider pin. Just to ensure both pads apply pressure easier together. Single piston calipers suck lol, but they're cheap

 

[Sprinkle_Star]

okay, here's my question.

How often should the slider pins be inspected and lubed if not performing a full brake job? should i check on them every 6 months? annually?

 

[Sprinkle_Star]

I should also add that, when i did my brakes last time, i made sure the pins were properly lubricated so as to prevent water intrusion; the grease is applied end to end on the pins. i guess what i could do is check the pad life every oil change since i do a tire rotation in the same span of time

 

[Capri to ST]

Glad you found the issue, I would ask them if they lubed the slider pin. Just to ensure both pads apply pressure easier together. Single piston calipers suck lol, but they're cheap

I'll do that, thanks. Two questions -
Once the wheel is off, can you lube the slider pin on the caliper without disassembling anything, or do you have to do some disassembly to get to it?

Do you lube the slider pins on the front and rear calipers, or just on the fronts?

 

[Sprinkle_Star]

It's easy, and yes you must lube all slider pins front and rear using silicone since that wont degrade the rubber boots. just take one slider pin out at a time and torque them properly

it's best to clean everything thoroughly (where the pins are housed) but a quick lube is okay i suppose.

front slider pins: 19 lb.ft (228 lb.in)
rear slider pins: 26 lb.ft (312 lb.in)

 

[Sprinkle_Star]

oh yeah make sure you re-apply blue threadlock to the bolts

 

[WannabeST]

okay, here's my question.

How often should the slider pins be inspected and lubed if not performing a full brake job? should i check on them every 6 months? annually?

Me specifically, I do it every time I do a brake job. I take my car to the canyons often so my brake intervals are more frequent than a daily driver. My brake pads are typically noisier than regular pads too, so I usually don't notice any change in sound.

 

[M-Sport fan]

Glad you found the issue, I would ask them if they lubed the slider pin.

This is my very first question (besides IF they would even do the job with my supplied pads, rotors, and fluid) to any shop or dealer, when inquiring about a brake replacement job.

 

[WannabeST]

I'll do that, thanks. Two questions -
Once the wheel is off, can you lube the slider pin on the caliper without disassembling anything, or do you have to do some disassembly to get to it?

Do you lube the slider pins on the front and rear calipers, or just on the fronts?

After you jack up the car and take the wheels off, it is basically a 2 bolt removal. Very simple job to only lube the slider pins and it would be a good first maintenance item for you to tackle on your own, you should gain the confidence to change your brakes in the future as well.

I'd recommend you grab some gloves, ratchet and socket (I forget the size), brake specific silicone because other ones could wear out the rubber pre maturely, blue loctite for when you re assemble and a rag or shop towel incase you put too much silicone and it spreads out.

 

[WannabeST]

This is my very first question (besides IF they would even do the job with my supplied pads, rotors, and fluid) to any shop or dealer, when inquiring about a brake replacement job.

It's a shame most people don't see this as an essential part of the brake job, its like 5 minutes or less time added to the job and it helps keep the noise level down and everything in proper spec.

 

[M-Sport fan]

^^^Yes, I'd love to got to fixed calipers (in the front at least) in order to eliminate this necessity, and the problems it brings if neglected, along with all of the other benefits they bring.

But my actual need for this, as well as the price for the (wheel spacers NOT needed to fit) kit I desire, which will fit under all of my wheels, is astronomical.