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Not sure of that. But it's been going on for a few months now and I've not noticed anything stuck in the tyres while being around the car. I changed the brake pads a few thousand miles ago. I'm wondering if one of the pins has come lose and the pad is flapping in the caliper? Could that happen? The pins are only slotted into the caliper. Same as they are on all the Brembo calipers I've seen. I've often wondered whether they could fall out.
You need to tap the pins out in order to get them out. Then you tap them back in until you hear that definite metal "clang" noise of it bottoming out. There is no way the pin will just come out if you tapped it in correctly. On my Brembo's on my STi they went a set further and all the pins have a small hole drilled through them and you use tiny $6 each cotter pins to prevent the retaining pins from backing out.
Honestly for how easy it is to take the pads in and out of Brembo calipers I'd say take everything apart and look it over then re-assemble the clicking side. Should take you 30 minutes tops and you can then be sure that nothing is wrong. Nothing is stuck or a piece of debris logged somewhere it shouldn't. Any scoring on the rotor, that would be a tell sign of something stuck like a rock or something.
yeah, reasonable suggestion RE taking it apart for a quick look. I can't detect any reduction in braking performance.
I like what you said about the pins... i.e. they can't come out.... but on your STI they have cotter pins... so can they come out without cotter pins? If they can't then why have cotter pins?
Did you check all the suspension components? Clicking could be CV joint, wheel bearing and lots of other suspension stuff. Harder to say if it'd be other things like sway bar links, ball joints, control arms. Lots of possibilities, best to get it on a lift and check around.
In theory they could come out IF the metal shim was not springy. IE: If for whatever reason the metal fatigued enough to where it snapped (not sure how this would ever happen) then under the right circumstances it might happen if say you were on the track and hit a major bump that would be enough jarring force to make the pin loose. In all reality I think it's next to impossible to do. I've tracked my STi and it's gone around the paces many times over and I've never had a brake failure of any kind with parts. Fade yes, but that's to be expected depending on how you are driving/how hard...etc. The cotter pins are just another layer of safety. Just like when one safety wires bolts on their motorcycle when on a track... if torqued properly bolts shouldn't come loose, but they do, and because of this safety wiring is another layer of security to ensure that critical parts just as caliper bolts, or fork pinch bolts don't accidently undo themselves and create a pretty bad day for ya.
This is what my brembo brake kit looks like for the fronts. You have the center shim to keep the pads down, the two pins and then the two cotter pins. Second picture is of Mercedes. You will see they have the expanding clip on the end. Once tapped in they aren't coming out without using a punch/hammer. Not sure which design is better to be honest because they both do the same exact thing.
Did you check all the suspension components? Clicking could be CV joint, wheel bearing and lots of other suspension stuff. Harder to say if it'd be other things like sway bar links, ball joints, control arms. Lots of possibilities, best to get it on a lift and check around.
Naa, not suspension, it happens exactly when you press the brake pedal. It sounds like the ABS is kicking in... it's that sort of pulsing noise.... but a bit slower than ABS and definitely coming from the right side of the car. My first instinct says it is a brake pad flapping in the caliper. But it isn't one I've come across before on any other car I've had.
If it was a wheel bearing it would be constant. If it was a CV joint it would be coming from the rear.
Given that the noise is a pulsing sound it must be connected with the rotation of the wheel.
I guess my best bet would be to take the wheel off and have a look.
In theory they could come out IF the metal shim was not springy. IE: If for whatever reason the metal fatigued enough to where it snapped (not sure how this would ever happen) then under the right circumstances it might happen if say you were on the track and hit a major bump that would be enough jarring force to make the pin loose. In all reality I think it's next to impossible to do. I've tracked my STi and it's gone around the paces many times over and I've never had a brake failure of any kind with parts. Fade yes, but that's to be expected depending on how you are driving/how hard...etc. The cotter pins are just another layer of safety. Just like when one safety wires bolts on their motorcycle when on a track... if torqued properly bolts shouldn't come loose, but they do, and because of this safety wiring is another layer of security to ensure that critical parts just as caliper bolts, or fork pinch bolts don't accidently undo themselves and create a pretty bad day for ya.
This is what my brembo brake kit looks like for the fronts. You have the center shim to keep the pads down, the two pins and then the two cotter pins. Second picture is of Mercedes. You will see they have the expanding clip on the end. Once tapped in they aren't coming out without using a punch/hammer. Not sure which design is better to be honest because they both do the same exact thing.
-Nigel
STi Brembo
Mercedes Brembo
the second of those two setups is the common type I've seen more of. I suspect with vibration or maybe debris or even maybe pressure washing at the hand carwash... there is scope for those pins to work their way out.
But I guess the only way to know if that's got anything to do with it would be to have a look.
I think the problem might have been the brake light switch. £11.13 +VAT from the dealer and in stock for immediate collection.
I found out about this problem because a couple of days ago ESP inoperative message came onto the dashboard together with the yellow warning triangle. It also took out speedtronic and run flat tire indicator.
A good local garage connected their diagnostics device and we read codes 7266 Distronic: Consequential fault / 430A Check component S9/1 (Stop lamp switch) and 7273 Distronic: Consequential fault
As 7266 & 7273 were shown as 'consequential' I reasoned that's exactly what it meant and targeted the Stop lamp switch as the possible cause. The part was very cheap and available for immediate collection from the dealer. There is a black plastic cover which blocks access to the area above the pedals so you remove three torx screws and pull that cover down enough to get your hand in. Disconnect the electrical connector from the switch, turn the switch clockwise 90-degrees and pull it out. Refitting is reverse of removal. Because the fault disappears every time you turn off the ignition you don't have to have any equipment connected for the light on the dash to stay off. There may be some residual record kept on the system to show this fault had occurred in the past but basically it's a cheap and cheerful fix to what could be a worrying problem.
The reason the dealer has it on the shelf is because they're a common fault item. I think they're also available aftermarket... but so cheap you may as well go original.
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