Violent shaking while braking, Stoptech ST-60

[FulhamFTW]

So I've had some shaking issues that were diagnosed as warped rotors and pad deposits. They only happen during hard braking and caused vibrations while cruising between 55 amd 65 mph. Just replaced the friction rings and pads and the cruising vibration is gone for the most part, but the braking vibration is still there and seems to be worse now. Any ideas as to what else it could be? Tie-rods maybe? Any insight is greatly appreciated.

[Blackstallion]

Curious to hear some ideas - I had same problem with exact BBK setup. Eventually replaced rotors/pads which definetly helped but I've stoll noticed vibration (not as bad pre rotor replacement) during highway speeds when exiting a off ramp...

[jran76]

How did you bed the pads?

[FulhamFTW]

Curious to hear some ideas - I had same problem with exact BBK setup. Eventually replaced rotors/pads which definetly helped but I've stoll noticed vibration (not as bad pre rotor replacement) during highway speeds when exiting a off ramp...

That is exactly when I have my vibration. Everything else is fine, but whenever I exit the highway and hit about 50mph, it starts to shake. Pads were bedded by the Audi dealer here that did the install. They said they followed the instructions that came with the replacement rotors.

[jran76]

I would maybe try to rebed the pads. 10-12 back-to-back stops from 60-80 mph. That's helped on my Stoptech kits in the past. Do you know if they replaced the rotor hardware when the replaced the rings?

[FulhamFTW]

I would maybe try to rebed the pads. 10-12 back-to-back stops from 60-80 mph. That's helped on my Stoptech kits in the past. Do you know if they replaced the rotor hardware when the replaced the rings?

I'll try to rebed the pads. And yes, they did replace the hardware.

[paul]

always rule out easy things first... rotate wheels, swap wheels if you have a second set.

[evanb]

I had a similar problem on my B5. As strange as it sounds, it turned out to be a wheel/tire balance issue.

[FulhamFTW]

always rule out easy things first... rotate wheels, swap wheels if you have a second set.

Any chance an out of balance wheel would cause the shaking while braking? I've also actually noticed continued vibration above 68mph. I'm taking it back to the dealer tomorrow morning.

[jygesq]

Get road force balance with HUNTER. 9700 wheel balancer. Lots of bad things happen when wheels are not balanced.

[Kay87]

do a tire balance and remove any spacers. recently i just changed my brakes and i did a tire balance and spacer change, it is all good after. braking is so smooth now

[MrFunk]

I had the exact same issue.

I had TyrolSport Rigid Caliper Slider stiffening kit installed which seized. I remember during the install they had trouble getting them and had to shave them down a bit so perhaps that was the issue - regardless, they started binding about 6 months later causing violent shaking under braking - the heavier the braking the worst it shook as if the front of the car was hopping up and down. I first though it was a warped rotor - replaced both front and continued having the problem. Finally took it in to the dealership and they confirmed the caliper sliders were seized.

I ended up having to replace both front calipers.

I'd have them check your calipers for proper function even if they are entirely stock.
Do your brakes smell like they are burning ever? Mine did...

[FulhamFTW]

I had the exact same issue.

I had TyrolSport Rigid Caliper Slider stiffening kit installed which seized. I remember during the install they had trouble getting them and had to shave them down a bit so perhaps that was the issue - regardless, they started binding about 6 months later causing violent shaking under braking - the heavier the braking the worst it shook as if the front of the car was hopping up and down. I first though it was a warped rotor - replaced both front and continued having the problem. Finally took it in to the dealership and they confirmed the caliper sliders were seized.

I ended up having to replace both front calipers.

I'd have them check your calipers for proper function even if they are entirely stock.
Do your brakes smell like they are burning ever? Mine did...

I hope it's not the caliper. They're stoptechs, so they aren't cheap. And they smelled a little at first after I replaced the rotors and pads, but my understanding is that it's normal. I also only seem to have the issue at highway speeds. Normal driving around town is just fine.

[FulhamFTW]

Ok, so dealer looked at it. Thougt it was related to the 3mm wheel spacers in the front. Took them off, put new lugs on, drove it 3hrs back to my home town(i was out if town at the time). Now there's a small pulsing at low speeds, and intermittent vibrations at highway speeds. Wheels balanced just fine, suspension parts are in good shape, and the rotors and pads are brand new. Anything else I should consider? Wheel bearing maybe?

[MrFunk]

I'm going to say it's your calipers. (I hope I'm wrong but that's what I'd have them look at most closely)
I had the shaking at highway speeds as well - not low in town speeds. What you are describing is almost exactly the problem I had.

[sirsycott]

i had this on stock calipers and ecs 2 piece rotors , and ebc red pads , this combo sucked and would vibrate when i was hard braking on freeway

swapping to stoptech actually fixed this hahaha

but i did get a bad screeching from the pad not settling correctly and leaning against the rotor on my 380 mm stoptechs
(also noticed the edge and corners of the pad cracking and slightly crubling at the edges and ends)
swapping the pads and spraying anti-squeel fixed most of this for me

i get a very light shudder from pad deposits every once in a while, so i'm planning on switching to a heavier biting pad since i believe the stop tech street pads are way too soft and brittle

[Victor Newman]

not saying this is your problem, but the stoptech street pads are horrible, and will judder. switch to something more abrasive

[FulhamFTW]

I'm going to say it's your calipers. (I hope I'm wrong but that's what I'd have them look at most closely)
I had the shaking at highway speeds as well - not low in town speeds. What you are describing is almost exactly the problem I had.

Winner, winner chicken dinner....caliper isn't fully retracting

[MrFunk]

Winner, winner chicken dinner....caliper isn't fully retracting

Yeah - the sliders. Same problem I had.
Hopefully stoptech can help you out.

[FulhamFTW]

Yeah - the sliders. Same problem I had.
Hopefully stoptech can help you out.

I actually just ordered a Q5 kit from ECS because I need to get things fixed quickly. I'm going to rebuild the stoptechs and do some custom work to them that I will hopefull share on here, depending on how it goes. Then decide to either sell the stoptech kit or swap it back on and sell the q5 kit.

[MrFunk]

I actually just ordered a Q5 kit from ECS because I need to get things fixed quickly. I'm going to rebuild the stoptechs and do some custom work to them that I will hopefull share on here, depending on how it goes. Then decide to either sell the stoptech kit or swap it back on and sell the q5 kit.

Nice. I'd be interested on your impressions of the Q5 kit.
How much did they end up being? I"m guessing you'll just use your current rotors?

[FulhamFTW]

Nice. I'd be interested on your impressions of the Q5 kit.
How much did they end up being? I"m guessing you'll just use your current rotors?

The ECS kit came with rotors. I'm curious to see how it works as well. The good part is I have to really refinish the stoptechs and if I don't like the Q5 kit, I'll swap the stoptechs back on.

[FulhamFTW]

Yeah - the sliders. Same problem I had.
Hopefully stoptech can help you out.

Did stoptech do anything for you? I'm the third owner of this car and the brakes were installed by the first owner. I doubt stoptech will help me anything at this point.

[MrFunk]

The ECS kit came with rotors. I'm curious to see how it works as well. The good part is I have to really refinish the stoptechs and if I don't like the Q5 kit, I'll swap the stoptechs back on.

The Q5 calipers are wicked ugly. Are you going to powder-coat them?

Did stoptech do anything for you? I'm the third owner of this car and the brakes were installed by the first owner. I doubt stoptech will help me anything at this point.

I didn't/don't have stoptech calipers. Mine were OEM calipers with aftermarket solid sliders.
Yeah I doubt they would do anything - I wouldn't even bother asking unless you were the 1st owner and still covered under warranty.

[FulhamFTW]

The Q5 calipers are wicked ugly. Are you going to powder-coat them?



I didn't/don't have stoptech calipers. Mine were OEM calipers with aftermarket solid sliders.
Yeah I doubt they would do anything - I wouldn't even bother asking unless you were the 1st owner and still covered under warranty.

Yeah, I'm definitely painting them prior to installation. My rear calipers are red too, so it would look like garbage if I didn't

[BlownOne]

You might want to check the rotor hat because I chased a bad baraking vibration for weeks before I figured it out. I tried tightening the caliper bolts with loctite, tightening the bridge bolts (these don't need to be tight), bedding the pads 4 times (like brakes on fire aggressive bedding), pulled the rotors and sanded them with garnet paper for two hours then finally took the rotors to a machine shop to have them resurfaced. This was assuming pad deposits were causing the issue. The machine shop noticed an out or round wobble on one of them and then noticed the original owner beat the aluminum rotor hat with a ball-peen hammer leaving dings which caused the massive vibration. I ordered a new hat for $400😳, new hardware for $60, put it together and it was perfect. Also switched from their track pad that came with the kit, to their street pads and I'm 100% happy.

Will

[FulhamFTW]

You might want to check the rotor hat because I chased a bad baraking vibration for weeks before I figured it out. I tried tightening the caliper bolts with loctite, tightening the bridge bolts (these don't need to be tight), bedding the pads 4 times (like brakes on fire aggressive bedding), pulled the rotors and sanded them with garnet paper for two hours then finally took the rotors to a machine shop to have them resurfaced. This was assuming pad deposits were causing the issue. The machine shop noticed an out or round wobble on one of them and then noticed the original owner beat the aluminum rotor hat with a ball-peen hammer leaving dings which caused the massive vibration. I ordered a new hat for $400😳, new hardware for $60, put it together and it was perfect. Also switched from their track pad that came with the kit, to their street pads and I'm 100% happy.

Will

I'll definitely take a look when I get everything off. The Q5 kit is a decent bandaid for now. I had planned on doing some custom work to the stoptech kit anyway, this issue has just sped things up. I want to repaint them a burnt copper color and maybe do a custom faceplate on the caliper. The calipers were scraped by the previous owner who mounted wheels that didn't completely clear, so they got gouges on them. If all works as planned, I'm going to have the faces milled or sanded down just enough to level out the gouges and then see about a custom faceplate. It all depends on the thickness of the caliper and if will allow for me to mill down without damaging the caliper permanently. I may able to get away with just sanding it, but we will see.

[rubicant5x]

I'll definitely take a look when I get everything off. The Q5 kit is a decent bandaid for now. I had planned on doing some custom work to the stoptech kit anyway, this issue has just sped things up. I want to repaint them a burnt copper color and maybe do a custom faceplate on the caliper. The calipers were scraped by the previous owner who mounted wheels that didn't completely clear, so they got gouges on them. If all works as planned, I'm going to have the faces milled or sanded down just enough to level out the gouges and then see about a custom faceplate. It all depends on the thickness of the caliper and if will allow for me to mill down without damaging the caliper permanently. I may able to get away with just sanding it, but we will see.

Just for curiosity's sake, when you swap the Q5 kit on, let us know the pedal feel differences between the two if you don't mind. What are the caliper stats compared to the Q5 kit (rotor size, # of pistons, etc)?

[Bruno_s4]

So my little Stoptech story is really long but I'll give you coles notes:

Stoptech ST60 V1 on a B7 S4 Avant
Horrible vibration on the highway but not during braking.... random times. Usually at speed.
Chased it for an entire summer.
Nobody could figure it out.
Ended up being the aluminum guide where the pads slide onto.
On the V1 ST60 they had issues where corrosion would occur between the caliper material and the slider which would pinch the pads.
Made sense since it was so difficult to remove pads during track swaps.
I wasn't the original owner but had the receipt and made a big stink with Stoptech (and the parent company's CEO) and eventually they sent me two brand new calipers at no charge.
This was back in 2013.
If I lived in California or Florida it wouldn't have happened but taking the Stoptech's through the winter did it.
The redesign of the V2 (that they currently sell) fixed the issue.

That being said, I have the Q5 Calipers sitting beside me waiting for spring to install on my current car. Painted black.

[FulhamFTW]

So my little Stoptech story is really long but I'll give you coles notes:

Stoptech ST60 V1 on a B7 S4 Avant
Horrible vibration on the highway but not during braking.... random times. Usually at speed.
Chased it for an entire summer.
Nobody could figure it out.
Ended up being the aluminum guide where the pads slide onto.
On the V1 ST60 they had issues where corrosion would occur between the caliper material and the slider which would pinch the pads.
Made sense since it was so difficult to remove pads during track swaps.
I wasn't the original owner but had the receipt and made a big stink with Stoptech (and the parent company's CEO) and eventually they sent me two brand new calipers at no charge.
This was back in 2013.
If I lived in California or Florida it wouldn't have happened but taking the Stoptech's through the winter did it.
The redesign of the V2 (that they currently sell) fixed the issue.

That being said, I have the Q5 Calipers sitting beside me waiting for spring to install on my current car. Painted black.

That's definitely interesting, I might reach out to them.

[FulhamFTW]

So I got the Q5 kit installed. First impression is that they don't brake as hard or as immediate as the stoptech kit. They work well and the vibration issues I was having are completely gone now though, so I can't complain too much. Now to start working on rebuilding the stoptechs.

[Boris]

So I got the Q5 kit installed. First impression is that they don't brake as hard or as immediate as the stoptech kit. They work well and the vibration issues I was having are completely gone now though, so I can't complain too much. Now to start working on rebuilding the stoptechs.

Is that yellow or gold? I can't tell. Looks clean either way

[SwankP3RF3ct10n]

Looks orange.

[FulhamFTW]

VHT Burnt Copper

[EHesh14]

Really great job on painting them!

[yjypm]

S4 stickers + clear coat these would be perfect

[FulhamFTW]

S4 stickers + clear coat these would be perfect

Definitely plan on S4 decals. Just couldn't get them delivered before the install.

[FulhamFTW]

UPDATE: So, I tore into the calipers and found that it was definitely the abutment blocks/plates that were causing the issue. Over time, they became corrroded and caused the plates to push against the pads, not allowing them to retract away from the rotors. This is what I spent my day off today doing.....it wasn't fun. Two of them are still stuck on the caliper and I'll have to chisel around the bolt heads to get them loose...and this is just the first caliper. I'll keep posting more pictures as I make progress.

[rubicant5x]

UPDATE: So, I tore into the calipers and found that it was definitely the abutment blocks/plates that were causing the issue. Over time, they became corrroded and caused the plates to push against the pads, not allowing them to retract away from the rotors. This is what I spent my day off today doing.....it wasn't fun. Two of them are still stuck on the caliper and I'll have to chisel around the bolt heads to get them loose...and this is just the first caliper. I'll keep posting more pictures as I make progress.

Good news is that your pistons look in pretty good shape minus the build up. Looks like these will make a nice recovery with a little TLC.

[FulhamFTW]

Good news is that your pistons look in pretty good shape minus the build up. Looks like these will make a nice recovery with a little TLC.

Yeah, pistons look great actually. Which is surprising given the state of everything else. I'm replacing the abutment pieces as well as the crosover tubes on both calipers. I'm also stripping them, powder coating them, and hopefully adding a custom faceplate if I can find a place local that eill cnc me some pieces. Should look pretty awesome after it's done.