Intermittent noise from brakes

[mechatron]

Hi Guys,

I'm just curious if other members on here are experiencing a smiliar noise with their VT -VZ Harrop / HSV brakes. I have the Harrop Performance Brake Kit ...i.e. 4 piston all round with 343mm x 32mm rotors on the front and 343mm x 28mm on the rear on my VY SS. I’m getting a slight intermittent noise for a short period of time after braking that is most noticeable when turning a right hand corner or doing a U-turn. (NOT while braking like many posts on here). I’m not 100% sure, but it sounds like the brake pads are just coming into contact with the rotor after braking. It isn’t a squealing or a scrapping noise, more like a squeaking noise like “eee”, with random pauses in between…i.e. like “eee”, then a slight pause, then “eee”, then a slight pause and so on. I've had the following pad retainer brackets installed in the calipers to stop pad movement.

http://i284.photobucket.com/albums/ll5/mechatron9680/CCB83D5C-37D1-4A6A-87D4-659A6AD7CBB4-9329-00000B7B9CB13DCF_zps400b2365.jpg (http://s284.photobucket.com/user/mechatron9680/media/CCB83D5C-37D1-4A6A-87D4-659A6AD7CBB4-9329-00000B7B9CB13DCF_zps400b2365.jpg.html)

http://i284.photobucket.com/albums/ll5/mechatron9680/B05DEF01-1B15-49A7-B767-078AE63E80F4-3365-0000048FEC351FBE_zps2652eb16.jpg (http://s284.photobucket.com/user/mechatron9680/media/B05DEF01-1B15-49A7-B767-078AE63E80F4-3365-0000048FEC351FBE_zps2652eb16.jpg.html)

I’ve pulled at the brake pads while the car is stationery and the pad retainers seem to be doing a good job at holding the pads in place as there isn’t any movement…however I think the pads are maybe still sticking to rotor after braking. Has anyone had this problem and overcome it somehow? Do you think that I need to use some brake pad glue to hold the pads in place as well as having the pad retainer brackets? Or do you think it's something else?

Note: The rotors are definitely square on the hub, the brake pads have been chamfered and the rotors and brake pads have plebty of meat on them. What are everyone's thoughts?

[white lie]

Is it only noticable at lower speed?
May just be rubbing at the slots on the rotors (or even just one of them)

I get it from one of my rears occassionally when i'm crawling along

[mechatron]

Thanks for the reply white lie.

I've only noticed it at really slow speeds. Like when I'm turning into my street which is the 2nd house in (#3) or when going slow to do a U-turn. And sorry, intermittent was probably the wrong word to use as it seems to happen everytime I turn a corner after braking (hard or soft)...i.e. it is regular for a short period of time but with pauses in between

[mechatron]

White lie, do you get the noise while going straight (after braking) or when going around corners at a crawling speed?

[white lie]

Bit of both I think. More noticeable going straight as I crawl up a laneway to get to my driveway and always hear it then, I'm not usually going slow enough around corners to pick it up

[mechatron]

Thanks white lie, so can I conclude that this noise is just a consequence of having slotted rotors?

And just to confirm...you get this noise after braking while your foot is NOT on the brake pedal?

[sv300 - 75]

i had a similar issue with my Harrop brakes a couple of months ago (same kit as you).
i had a humming sort of noise that would happen mostly going around right hand bends at about 40km/h
it was sort of random thought because some times it would happen all the time and others it would not happen at all.

it turned out that the brake pad was making a resonance sort of noise with the rotor so the mechanic machined about 1 to 2 mm off the passanger side rear pads and it fixed it.
now i have all new brake rotors and new pads so i dont have any noises. (and they are slotted)
thats the only up side to cooking your pads and rotors on a race track, new brakes all round.

[mickeyVX350]

I THOUGHT my exes VTII with HSV brakes was rubbing a pad... it was the LSD needing the additive. I only noticed after it was a bit warm, at low speeds and usually turning - everything you have described. It did my head in as I kept justifying that it MUST be brakes.

Not saying yours is a diff, but its wort a look, so next time yo go for a drive, reverse and turn, reverse and go straight, and turn the other side.

[mechatron]

i had a similar issue with my Harrop brakes a couple of months ago (same kit as you).
i had a humming sort of noise that would happen mostly going around right hand bends at about 40km/h
it was sort of random thought because some times it would happen all the time and others it would not happen at all.

it turned out that the brake pad was making a resonance sort of noise with the rotor so the mechanic machined about 1 to 2 mm off the passanger side rear pads and it fixed it.
now i have all new brake rotors and new pads so i dont have any noises. (and they are slotted)
thats the only up side to cooking your pads and rotors on a race track, new brakes all round.

Thanks SV300. I just need to work out which corner is making the noise and maybe get the pad machined down a bit

[mechatron]

I THOUGHT my exes VTII with HSV brakes was rubbing a pad... it was the LSD needing the additive. I only noticed after it was a bit warm, at low speeds and usually turning - everything you have described. It did my head in as I kept justifying that it MUST be brakes.

Not saying yours is a diff, but its wort a look, so next time yo go for a drive, reverse and turn, reverse and go straight, and turn the other side.
Thanks for the suggestion Mickey but my diff has a TrueTrac

[mechatron]

Trying to work out if its a sticky piston. Anyone know of a good honest brake shop between say Penrith and St Marys (NSW)?

[fuel]

I have a similar noise at the moment, I thought it was my diff, but I believe it is slightly warped rear discs.

[white lie]

Go see Race Brakes Sydney. Little bit further down the road but well worth it. I get all my brake parts from Matt and I'm on the other side of the country! They have a very good reputation :)

[mechatron]

Go see Race Brakes Sydney. Little bit further down the road but well worth it. I get all my brake parts from Matt and I'm on the other side of the country! They have a very good reputation :)
Thanks mate. Yes Matt from Race Brakes is great to deal with. I bought my braided brake lines from him. I spoke to him today but he is usually only there by himself meaning that he would have to close his shop while he goes for a test drive with me. I just have to wait for a day when his mechanic is there.

Also I just went for a drive with a passenger and they said the noise is coming from both the rear left and rear right corners.

Could it be something to do with the handbrake shoes?

[white lie]

Try pulling it on a click or two and see if it's still there or goes away or pull it up when you can hear it. Same with the brake pedal, should give you something to go on.

[sv300 - 75]

mate im not saying that you should go out and shave bits off your brake pads, its just an idea that my mechanic tried and i agreed with.
i knew that if it didnt work i would be replacing the pads and maybe some other things when i was trying to get rid of the noise.

i did lots of work before i got to the brakes, i had new wheel bearings put in, had the diff checked and it was sort of ruled out as a more expensive fix so it was going to be last.

i would suggest that you keep searching for the noise and maybe take a mate in the car and see if they can find the location of the noise.

[mechatron]

Try pulling it on a click or two and see if it's still there or goes away or pull it up when you can hear it. Same with the brake pedal, should give you something to go on.
I haven't tried using the handbrake as yet, however I have applied the brake pedal slightly (while still rolling) when this noise occurs and the noise does go away for the time the brake is applied.


What does this indicate?

[mechatron]

mate im not saying that you should go out and shave bits off your brake pads, its just an idea that my mechanic tried and i agreed with.
i knew that if it didnt work i would be replacing the pads and maybe some other things when i was trying to get rid of the noise.

i did lots of work before i got to the brakes, i had new wheel bearings put in, had the diff checked and it was sort of ruled out as a more expensive fix so it was going to be last.

i would suggest that you keep searching for the noise and maybe take a mate in the car and see if they can find the location of the noise.

No worries, thanks bud.

I did have my wife in the car tonight listening to the noise while i was driving and she is certain that the noise is coming from the rear on both sides

[white lie]

I haven't tried using the handbrake as yet, however I have applied the brake pedal slightly (while still rolling) when this noise occurs and the noise does go away for the time the brake is applied.


What does this indicate?

I would say it's not the handbrake shoes then.

[amckiwi]

I get that noise on the VE from time to time when going straight
If I turn right even slightly it goes away.
I also get a different squeek at low speed as well
Stu

[mechatron]

Thanks heaps for your input guys...I think the best thing to do is see Matt at Race Brakes when he has the time.

[sv300 - 75]

what you might find is that the noise is a vibration or resonance.
therefore when you apply the brake (even a little) the brake pad will transfer the vibration to the car and it will stop (sort of like putting your hand on a fan to stop the blades spinning).
if you apply the brake it will also take load off your diff which might change or stop the noise.

there are just other suggestions.

i know what its like to have a noise in the car that you cant get rid of, drives me mad.

[mechatron]

Thanks for your input sv300. The noise does my head in a little bit. I just want to know if its kind of normal and acceptable. If it is, I'll get over the noise. I'll hopefully talk to a brake pro this week some time

[IJ.]

Try some "Brake Quiet" it's a spray on high temp glue you apply to the backs of the pads to stick them to the pistons.

Disc Brakes are self adjusting by nature and use a square section O ring to act as the return springs for the pistons so you have very limited return distance, if the pads are free to flop around in the Caliper body the pads can "lean" onto the Rotor resulting in noise, gluing them to the Pistons prevents this so you have quiet brakes.

[mechatron]

Try some "Brake Quiet" it's a spray on high temp glue you apply to the backs of the pads to stick them to the pistons.

Disc Brakes are self adjusting by nature and use a square section O ring to act as the return springs for the pistons so you have very limited return distance, if the pads are free to flop around in the Caliper body the pads can "lean" onto the Rotor resulting in noise, gluing them to the Pistons prevents this so you have quiet brakes.

Thanks mate, good idea...I'll talk to Matt about this.

[mechatron]

Thanks for everyone's inputs.

I've paid a visit to a few brake specialists, had the car jacked up with the rear wheels off & everything is functioning correctly. Apparently a simple pad change on the rears (with a softer compound) will fix this noise.