Brake noise

[alastairg]

Recent front brake pads and backing plates. Still get pad/disc noise. Is there a permanent solution or is this a characteristic of the design ?

Do they need a strip down with new pins or just harder driving (which solves the problem but upsets passengers !! )

[robo]

I had the same problem with btakes noise, end result was brand new big reds with 322mm discs and pads ,
Alastairq did you get your backing plates stuck to pads, if you did I think tou ned to strip calipers ,clean them and get new guide plates.I did that it helped but only for 3k miles.

[alastairg]

yes, they did all the correct work including removing corrosion/new back plates etc. I will have a word when it goes in for the new exhaust piece

[super-g]

Alastair

I had the same problem and resolved it by not sticking the brake pads to the backing plate, (silly idea anyway) do not even use copper ease as this can clog up and also cause sticking. You say you have referbed the brakes so its not the guide plates, if they are straight and not bulging from corrosion of the spacer block make sure the pads are able to move freely, shave a little of the metal side of the pads to get extra clearance, (this will help determind what the problem is) where they touch the guide plate, usually this does the trick. If you are trying to fit Porsche 968/928 front pads you are going to have to do this anyway.

This might sound strange but make sure the tracking is correct, if the noise goes when you turn the steering wheel the problem could be the brake fluid in the flexible brake pipe was applying a small amount of brake pressure to the pistons, if not but noise goes when turning the steering wheel check the air flow over the wheel and over the brake calliper i.e., make sure the plastic air duct on the bottom wishbone is attached firmly, this restricts air and water pressure building up under the wheel arch to allow low pressure air flow around the wheel and calliper.
The plastic air duct is not for washing, when driving in the rain the front wheels should remain fairly dry if this duct is in place, the wheel rims also get covered with brake dust but with the rear looking cleaner after a drive in the rain The noise can also come and go depending on how you are driving usually appearing when cruising at high speed because the outer brakepad falls slightly towards the disc part due to camber settings, but a good brake setup as described above normally minimises the noise.
Normally the usual cause is a sticking backplate when the pad locks in the upwards position hard against the guide plate, so not returning to the down position. Try not sticking the pad to the back plate first. Like to know how you get on!

Best

Talk soon

[alastairg]

Alastair

I had the problem and resolved it by not sticking the brake pads to the backing plate, do not even use copper ease as this can clog up and cause sticking. You say you have referbed the brakes so its not the guide plates, if they are straight and not bulging from corrosion make sure the pads are free to move, shave a little of the pads to get extra clearance, usually does the trick. If you are trying to fit Porsche 968 front pads you are going to have to do this anyway.

This might sound strange but make sure the tracking is correct, if the noise goes when you turn the steering wheel slightly the problem could be that the brake fluid in the flexible brake pipe was applying a small amount of brake pressure to the pistons, if not this but still noise goes when turning the steering wheel check the air is flowing through the wheel and over the brake calliper which is better for cooling i.e., make sure the plastic air dust on the bottom wishbone is attached firmly, this restricts air and water pressure under the wheels arch to allow air flow through the wheel into the wheel arch, it is not for washing, when driving in the rain the front wheels should remain fairly dry for better wet weather braking, mine easily get covered with brake dust with the rear looking cleaner after a drive in the rain

It can also come and go depending on how you are driving usually appearing when cruising at high speed but a good brake setup as described above normally minimises the noise

Normally the usual cause is a sticking backing plate when the pad locks in the upwards position hard against the guide plate so will not return although it should fall back down but over time will sticks in place. Try not sticking pad to back plate first. Like to know how you get on!

Best

Talk soon

Thanks again. Thats useful and I will check out with what I can and talk to specialist again. AFAIK DS 2500 ferodo 968 pads, new back plates,corrosion build up removed, dry fitted I think, original discs no lip wear,new front brake pipes. Tracking twice recently OK (local proalign then AMD after shocks)
Problem mainly cruising without heavy braking and usually worse in wet weather ie with passengers.
I can always solve it with a few hard applications. It no longer varies with steering lock as it did prior to refit

Ta again, as always will post solution if/when happens

[robo]

I think is a very bud idea to shave a bit of brake pads, if do that means ther is rubish under the guide plates , when i got my car the brake pads had 5mm taken of each side, you shoud not need to shave anything of if your calipers are referbed properly.

[super-g]

Well I don’t know how you can fit 968/928CS brake pads onto an Audi RS2 with stock callipers without having to shave about 3/5mm of each side. This is because the spacer’s block (very poor quality aluminium with poor corrosion protection) separating each piston housing is a different size to Porsche Callipers used on Porsche cars. The Brembo, Audi Porsche RS2 stock calliper uses smaller brake pads with Audi wanting to rip you of @ £174.00 per pair as apposed to £50 per pair for Porsche fitment to Porsche Callipers.

Even using standard pads if the aluminium block under the guide plate has corroded or is porous i.e., expanding/swelling the guide plate will be in the wrong position, solution, strip down and clean, treat with anti corrosion inhibitor, reposition guide plate, fit new pads but don’t and I mean don’t go and buy new brake callipers. As long as the pistons and seals are in perfect condition your callipers will be as serviceable as new ones, you have already paid a premium for the car, brakes etc, don’t spend any more of your hard earnt money on new brake callipers so that in 3 to 4 years time you are back to where you are now. Treated properly with a better and more liberal protection coating to the aluminium spacing block these refurbed callipers will out perform the factory ones.

I did this more than four years ago and are still in perfect working order, that’s longer than the original fitted so called quality Porsche/Audi ones with there pathetic protection coating. Regarding brake upgrade to the larger size, there is no gain in dry weather brake efficiency, with only slightly better in wet weather (as long as you have the plastic guard fitted on the bottom wishbone) when using the larger cross drilled brake disc, the larger diameter increase is lost by having holes added, this just puts you back to where you started, if the pads in a stock callipers can move freely and the brake disc is not heavily worn the stock brakes are excellent, remember these pads and callipers like to be warm to work at there best, cross drilled discs eat pads, warp more easily even crack when used really hard. I you can choose use grooved discs these are the best. By all means buy the larger brakes if you have to spend your money, they cost about the same as the original ones and brake pads are cheaper. Hope this help Talk soon

[alastairg]

Noise has stopped now. I presume due to pad wear giving more clearance than when new. I am interested if 968 pads were the correct 'porsche' rather than audi OEM choice. Refer this thread http://www.rs246.com/index.php?name=PNp ... pic&t=6319 that I have restarted.

[GlynRS2]

With reference to upgrading to Big Reds and larger discs, there is always the option of using the 928 GTS front disc which the same 322mm diameter but not cross-drilled, so you then should get some performance advantage.
Super G - would Big Reds be any less likely to suffer this corrosion problem the the standard RS2 calliper, even though it is the same basic construction? Or would we all be better off finding out if there is a more modern monoblock Porsche/Brembo calliper that would be a direct bolt on replacement to the RS2 bracket, ideally using a standard Porsche disc (304-330mm) and standard Porsche pads all that will fit nicely under our standard RS2 rims? Does such a thing exist? Or is that hoping for too much?

[robo]

With reference to upgrading to Big Reds and larger discs, there is always the option of using the 928 GTS front disc which the same 322mm diameter but not cross-drilled, so you then should get some performance advantage.
Super G - would Big Reds be any less likely to suffer this corrosion problem the the standard RS2 calliper, even though it is the same basic construction? Or would we all be better off finding out if there is a more modern monoblock Porsche/Brembo calliper that would be a direct bolt on replacement to the RS2 bracket, ideally using a standard Porsche disc (304-330mm) and standard Porsche pads all that will fit nicely under our standard RS2 rims? Does such a thing exist? Or is that hoping for too much?

I think if look after your calipers and clean under guide plates with every pads change they will last 10 years or more. Improoved preformance? oh yes , ask Mihnea he said my brakes are very good .
________
Rob

[GlynRS2]

With reference to upgrading to Big Reds and larger discs, there is always the option of using the 928 GTS front disc which the same 322mm diameter but not cross-drilled, so you then should get some performance advantage.
Super G - would Big Reds be any less likely to suffer this corrosion problem the the standard RS2 calliper, even though it is the same basic construction? Or would we all be better off finding out if there is a more modern monoblock Porsche/Brembo calliper that would be a direct bolt on replacement to the RS2 bracket, ideally using a standard Porsche disc (304-330mm) and standard Porsche pads all that will fit nicely under our standard RS2 rims? Does such a thing exist? Or is that hoping for too much?

I think if look after your calipers and clean under guide plates with every pads change they will last 10 years or more. Improoved preformance? oh yes , ask Mihnea he said my brakes are very good .
________
Rob

Thanks Rob, I am pretty certain I will go the Big Red route sooner or later. Did you manage to get a good price for your standard callipers when you upgraded?

[super-g]

Hello Alistair

Update info on Audi brakes.

If copper ease has worked for you then fine but its not recommended. The squeal is happening because of low pressure between the brake pad and disc caused by a sticking piston or brake shoe, the calliper may also requiring bleeding. Copper ease is a quick fix and will lead to clogging.

You can fit Porsche 928 club sport front discs plain or holed, but remember the problem with the holed discs is they will crack around the holes. This is greatly effected buy how long and hard you drive so if there are no cracks on high milers then they haven’t been driven hard in the Alps on a mission.

You can use 928CS brake pads but will have to machine (downsize) the metal sides for the pads to fit; this is nothing-new just custom fitting. This takes minutes with 75% costs saving compared to Audi. Textar Pads are excellent, should last 15,000 miles on average with enthusiastic driving, don’t worry about dust, it just washes off its the pads wearing not the discs, choosing a hard brake pad has no benefits on the road, yes requires less changes but will effect your pocket requiring disc replacement 3 to 1 over using textar pads.

You cannot use Porsche rear discs, the Audi RS2 have a different offset. You can use 911 brake shoes for the handbrake.

You can use Porsche CS rear pads but again custom fit as above.

Regarding callipers.
Corrosion is not such a problem on the new current designed Brembo callipers as the brake pads are held in position by pins centrally so no need for guide plates.

One thing for sure with RS2 calliper, Racing, the brake pad retainer makes for very fast changing.

Corrosion is not down to different metals reacting, Brembo are not that incompetent? The guide plate is stainless steel; it is purely down to quality of aluminium, design and protective coating. For sure in racing not a problem but racing and road is like chalk and cheese. If the intercooler were made from the same material it would last about 12 months.

Hope this helps.

best

[super-g]

Diagnosing:

First: if you are using the same Manufacturer brake pads, compound front are rear and the weather has been dry for a few days, look at the rear wheels for dust build-up and compare to front, rear should be slightly less.

Second: has the noise just appeared in the winter months? The callipers are machined to heavy high tolerances to avoid leakage and sticking at very high temperatures. From cold drive and brake slowly, do they squeal, now drive and brake hard to get the brake nice and warm, do they still squeal?
The rear brake have less forces so do not work as hard, this will cause them to squeal naturally in the cold, if this is the case you do not have a problem.

Upgraded brakes: not sure about corrosion as I have only driven, could not tell the difference from mine apart from the car drove like a dog. Do not use upgrade callipers unless you can get plain, grooved is best.

[alastairg]

Noise has all but gone. I am interested how my pads have been fitted as no alteration to pads was made although they removed corrosion build up. Time to get the bossman to check them. They do rub on full lock however and squeal only occasionally from cold.
Ta

[afhgus]

Just been reading all this break info. Sorry to say I have had fairly regular work carried out. Cleaning and stripping out,new front pads, and a recent 'break service' only a few weeks ago. And on the journey home that horrible grating noise returned! Disappeared on pressing the pedal though! And has returned a few times again. But I also seem to be getting a constant humming/slight griding noise which I feel is break related and will not go away. I think new runners are next! And prey. Has anyone had that constant humming noise? Muddy roads,and corrosion are the problem to this me feels. Thanks...