Brake shudder caused by pad deposits on TA front rotors

[Bruce H.]

I developed this following my 4th track day. Pedal doesn't pulse as with a warped rotor, but a roughness can be felt and heard. When I examined the front rotors I saw the patchy deposits, with the rears being perfectly clean. I thought I had bedded in the pads with a few progressively harder stops from 60 mph down to low speed, but maybe not enough for these brakes.

Has anyone else also experienced this, and what is the proper fix at this point? Thanks

Bruce

 

[Allan]

Need to remove the uneven brake pad transfer layer, then re-bed.
I think the best method would be to remove the rotors from the car, and get busy with the sandpaper.
Non-directional, even as possible. -Think of it as a Karate lesson,.... sand the rotor. ....both sides.
Spray them off with brake cleaner, then re-install, then bed them in again.

Then when you get done with that, continue the Karate lesson with the car's paint. Wax on, wax off......whole car.

 

[Bobpantax]

Hi Bruce. How many miles did you use to bed in the brakes. I was told by a tech friend to go easy for at least 100 during the initial break in.

 

[Bruce H.]

Hi Bruce. How many miles did you use to bed in the brakes. I was told by a tech friend to go easy for at least 100 during the initial break in.

Hey Bob, I may have had closer to a couple of hundred of very easy driving cruising home from the dealer before thinking about bedding the brakes, and then went out and made maybe 6-8 progressively harder brake applications from higher speed. In hindsight, I may have not braked hard enough given the particular pads used on the TA. I'm just surprised it took over 3500 miles and 4 track days (last two involving quite aggressive braking) to become an issue, with first being a light track day in the rain, and others getting more and more aggressive.

I was hoping I could take it out now and clean it off with a particular braking procedure, or see if I could do that at my next track day. Removing rotors to sand sounds like a lot more wrenching than I care to do.

Might this be covered under warranty?

 

[Bobpantax]

No harm in asking.

 

[VENOM V]

Bruce,

I'm fighting the same issue with my Motoman 3 track pads. Uneven build up. What's strange to me is that I didn't have this issue for the longest time, now I have it. Still learning about how to deal with it. I thought I may have had another issue that led to this, because it seemed my calipers didn't fully release when I was at Spring Mountain. When on a lift, the front wheels wouldn't turn as freely as they should, and I wasn't sure if this was caused by the fact that Motoman pads are so damned thick when new that you can barely install them. I've talked with Mark Jorgensen at length about this. I may try different pads or revisit whether I did my bedding procedure correctly. I do the same as you, but I ensure that the brakes get really hot (smoking literally). Then I drive around for a bit to cool them down. Then I let them sit overnight to let them completely cool. When I was at Spring Mountain I didn't have time to let them cool after installing new pads, and the problem recurred. The lead instructor at Spring Mountain described brake issues as an ongoing battle that all track rats face, so he didn't seem surprised when I was having issues. Let's keep in touch as we both learn more about this.

 

[Nine Ball]

Could you take a photo, to show us what it looks like on the rotor?

 

[Dan Cragin]

Scruff up the rotors or turn them. If you run the same pads you can get away with just changing them as long as there are not hot spots or transfer spots. If you change pad types then you always need to scruff or turn the rotors.

 

[Bruce H.]

Thanks for all the feedback guys. If anyone has a link covering rotor removal please let me know and I may have a go at it sanding it off, especially if it's possibly going to be a recurring issue to resolve. I've done rotors and pads on the other track cars so why should this one be any different! I knew recently installed a 2 post lift for more than just stacking cars

 

[TrackAire]

The shop near me uses 3M Roloc 2" Coarse abrasion pads to clean up minor buildup on rotors. It is small enough in diameter that you can often clean both sides of the rotor with the it still on the car.

Google the name for an image or to get an idea of how they look/work.

 

[steve911]

to remove the calipers unbolt the two allen head bolts from the caliper. Tie caliper out of the way. Remove rotor from wheel studs. Reverse to install.

 

[Stuntman]

Maybe try different pads. I'm a big fan of PFC 01s. They are bed and ready to go in a lap and don't have the uneven pad deposit shudder than many pads develop.

 

[JeffInDFW]

Bruce,

I'm fighting the same issue with my Motoman 3 track pads. Uneven build up. What's strange to me is that I didn't have this issue for the longest time, now I have it. Still learning about how to deal with it. I thought I may have had another issue that led to this, because it seemed my calipers didn't fully release when I was at Spring Mountain. When on a lift, the front wheels wouldn't turn as freely as they should, and I wasn't sure if this was caused by the fact that Motoman pads are so damned thick when new that you can barely install them. I've talked with Mark Jorgensen at length about this. I may try different pads or revisit whether I did my bedding procedure correctly. I do the same as you, but I ensure that the brakes get really hot (smoking literally). Then I drive around for a bit to cool them down. Then I let them sit overnight to let them completely cool. When I was at Spring Mountain I didn't have time to let them cool after installing new pads, and the problem recurred. The lead instructor at Spring Mountain described brake issues as an ongoing battle that all track rats face, so he didn't seem surprised when I was having issues. Let's keep in touch as we both learn more about this.

I do not own a 5th Gen, so I have no experience here. BUT.....from what you two guys are describing (it takes several track events to show up), and it is deposits on the rotor.....Then, I read what I underlined above.........It made me -wonder- if there might be an issue where the front brakes are not fully releasing, and that is causing an excessive amount of brake heat which takes time to finally over heat the pad material causing it to transfer like this.

Again, I'm just taking a stab in the dark but wanted to throw it on the table just in case it could help the discussion. Congratulations on your fantastic car.

 

[bluesrt]

after you buzz off the brake pad matter, on the cooldown lap try not to touch the brakes until they cool off, that's how you get that matter stuck to the rotor

 

[Bruce H.]

Any chance of it coming off on its own during a hot lapping session?

 

[bluesrt]

possibly, I have straightened them out by getting them smoking hot after a long run,then cooling them down without touching the brakes

 

[mjorgensen Woodhouse]

These are the procedures I have always gone by, good info here. http://www.ctbrakes.com/faqs.asp#bedding4

 

[AZTVR]

These are the procedures I have always gone by, good info here. http://www.ctbrakes.com/faqs.asp#bedding4

I hate those CT race brake bed-in instructions, myself. ( I use Carbotech XP brakes on my S2000 ) They have no specific meaning. Go on the track to some speed and brake some number of times, and then go faster and brake some more. I go to 1.7 mile tracks up to 3.2 mile tracks. Not ever the same one repeatedly. Tracks with 9 turns and lots of speed and tracks with 20 turns with hardly any straights to pick up a lot of speed. I have sometimes gotten spotty rotors just on break in. Did I follow there intent? Hell if I know.


_________________________________________________
Jim – ‘02 GTS ACR gray/silver -- sold – ( enthusiastic custodian for 8 years )

 

[Bruce H.]

Thanks for all the feedback. I'm waiting to hear from my dealer, whose probably waiting to hear from SRT, and I'll let you know. Right now I'm considering doing a lapping day next Wed to see if it clears up or gets worse. They aren't grabbing or pulsing really, so doesn't seem to be a safety issue.

 

[VENOM V]

Thanks for all the feedback. I'm waiting to hear from my dealer, whose probably waiting to hear from SRT, and I'll let you know. Right now I'm considering doing a lapping day next Wed to see if it clears up or gets worse. They aren't grabbing or pulsing really, so doesn't seem to be a safety issue.

Bruce,

Here's the risk in doing a lapping day without cleaning the deposits off first: The deposits are the only portion of the rotor that is touching the pads and will be absorbing heat while the other parts of the disk won't, those spots may heat treat into hard spots and ruin your rotors. It happened to me twice. But if they aren't really pulsing perhaps you'll be okay.

As for my battle with this, my new front rotors and new Brakemans began to have a problem with pad build up again, about 100 miles after installation (all street, no track). Today I decided to pull off the BrakeMan 3 track pads and put the OEM pads back on. When my brake guy turned the rotors, he found two hard spots beginning to form on the rotor, and this without doing a track day! This time I was fortunate in that he was able to sand them out, but last time they were so hard that I had to toss the rotors. Not sure what happened, and probably a different root cause than your issue. My guess is that for some reason the brakes were more or less dragging. The Brakeman 3s are so damn thick that you can barely get them in. Maybe they're dragging a little intermittently because of this thickness. Mark Jorgensen had a good theory that perhaps I have a little air in the lines and when the calipers try to release, the air is expandable and doesn't fully pull the calipers away the way pure fluid would. This air could be present due to a little fluid boil during brake bedding, even though the fluid was flushed prior to bedding the brakes. While I'm still not sure what's going on, it's time to try a different brake pad. The OEM pads worked well for me except the OEM fronts wore out much faster than I would expect (3-1/2 hard track days plus maybe 5,000 miles).

Your TA has different pads and pad compound than my Track Pack brakes do, so not sure what caused your issue. How thick are your front pads after all your track days? Jon B of Parts Rack has TA pads in stock if you need fresh ones. If I were you, I'd also pick up a set of front rotors as you'll need them eventually and it's nice to have them on hand.

 

[Bruce H.]

Todd,

I'm waiting to hear back from the dealer today, but am planning to pull a wheel and try a bit of sanding. My pads show little wear so far, but I wasn't pushing the brakes as hard as I will be now that I'm starting to lean on it more. So early days for me still, but my preference will be to stick with the OEM pad if I can, and I'm work on corner speed so I don't have to use them much

It sounds like you're having quite a time with yours. I'm not sure how comparable ours are, but hopefully with more guys tracking we can all sort out the issues. I'll let you know what happens with mine.

Bruce

 

[TrackAire]

Bruce,

Here's the risk in doing a lapping day without cleaning the deposits off first: The deposits are the only portion of the rotor that is touching the pads and will be absorbing heat while the other parts of the disk won't, those spots may heat treat into hard spots and ruin your rotors. It happened to me twice. But if they aren't really pulsing perhaps you'll be okay.

As for my battle with this, my new front rotors and new Brakemans began to have a problem with pad build up again, about 100 miles after installation (all street, no track). Today I decided to pull off the BrakeMan 3 track pads and put the OEM pads back on. When my brake guy turned the rotors, he found two hard spots beginning to form on the rotor, and this without doing a track day! This time I was fortunate in that he was able to sand them out, but last time they were so hard that I had to toss the rotors. Not sure what happened, and probably a different root cause than your issue. My guess is that for some reason the brakes were more or less dragging. The Brakeman 3s are so damn thick that you can barely get them in. Maybe they're dragging a little intermittently because of this thickness. Mark Jorgensen had a good theory that perhaps I have a little air in the lines and when the calipers try to release, the air is expandable and doesn't fully pull the calipers away the way pure fluid would. This air could be present due to a little fluid boil during brake bedding, even though the fluid was flushed prior to bedding the brakes. While I'm still not sure what's going on, it's time to try a different brake pad. The OEM pads worked well for me except the OEM fronts wore out much faster than I would expect (3-1/2 hard track days plus maybe 5,000 miles).

Your TA has different pads and pad compound than my Track Pack brakes do, so not sure what caused your issue. How thick are your front pads after all your track days? Jon B of Parts Rack has TA pads in stock if you need fresh ones. If I were you, I'd also pick up a set of front rotors as you'll need them eventually and it's nice to have them on hand.

If the OEM pads are working well, do you think the most efficient set up might be to run the OEM pads and just change them out every two track events to make everything else last longer (rotors, etc) making them the sacrificial part in the system?

You are driving much harder than the "normal" Viper track rat so your brakes are seeing an exponentially tougher life than an average track day warrior (the rest of us, lol). Bring lots of water this weekend

Cheers,
George

 

[Bruce H.]

Todd,
You might want to consider starting a thread just covering your different brake set-ups, and experience with them. You're blazing a trail with the GTS brakes, and others will be following that could benefit from your experience. You could update the thread as you go.

 

[Bruce H.]

Today I sanded off the pad deposits as much as possible (very small amount left), removed the pads to examine, checked for free movement of pads, and re-assembled. I noticed that almost all of the deposits were on the exterior rotor surface, with very little on the inside. I checked with a reputable Viper tech who suggested I not remove the rotors as the hat hardware could be damaged, so I wasn't able to sand the inside rotor faces, but again, there was very little deposits on them. Afterwards the brakes felt only ever so slightly better...still a little rough feeling and sounding. The tech suggested I try new pads, and since I can't get them before my next track day on Wed I'll just see how it goes with these. With any luck the pads will bed more evenly.

The OEM pads have ~2800 miles on them, including 2 light and 2 heavier track days, and there's still over 3/8" of pad thickness left out of maybe 1/2" thickness when new. I should be able to get another 3 track days out of them I would think.

 

[mjorgensen Woodhouse]

Today I sanded off the pad deposits as much as possible (very small amount left), removed the pads to examine, checked for free movement of pads, and re-assembled. I noticed that almost all of the deposits were on the exterior rotor surface, with very little on the inside. I checked with a reputable Viper tech who suggested I not remove the rotors as the hat hardware could be damaged, so I wasn't able to sand the inside rotor faces, but again, there was very little deposits on them. Afterwards the brakes felt only ever so slightly better...still a little rough feeling and sounding. The tech suggested I try new pads, and since I can't get them before my next track day on Wed I'll just see how it goes with these. With any luck the pads will bed more evenly.

The OEM pads have ~2800 miles on them, including 2 light and 2 heavier track days, and there's still over 3/8" of pad thickness left out of maybe 1/2" thickness when new. I should be able to get another 3 track days out of them I would think.

The thinner the pads get the faster they wear because they cannot dissipate the same thermo amount as full thickness pads and your fluid will also get hot faster because there is less insulator between the pad and the pistons.

 

[Bruce H.]

When do you recommend to swap them out, Mark....at maybe 1.5 times backer plate thickness? Wednesday's track day is local, but the next 2 are 10 hrs away at VIR where I will not want to be changing pads, nor will I be pushing that hard I suspect. I'll order new pads tomorrow to have them on hand.

 

[mjorgensen Woodhouse]

When do you recommend to swap them out, Mark....at maybe 1.5 times backer plate thickness? Wednesday's track day is local, but the next 2 are 10 hrs away at VIR where I will not want to be changing pads, nor will I be pushing that hard I suspect. I'll order new pads tomorrow to have them on hand.

Yeah that the max I would ever think of using a pad.

 

[VENOM V]

If the OEM pads are working well, do you think the most efficient set up might be to run the OEM pads and just change them out every two track events to make everything else last longer (rotors, etc) making them the sacrificial part in the system?

You are driving much harder than the "normal" Viper track rat so your brakes are seeing an exponentially tougher life than an average track day warrior (the rest of us, lol). Bring lots of water this weekend

Cheers,
George

George, great to see you at Thunderhill! That was a kick in the pants, we've got to get together on track soon. As you know, we had a bunch of Vipers out there, including Rich, Loyd and Jim in their badass ACRs.

Bingo on the OEM pads, I used them with great success this weekend. Even with 105+ degree weather and slicks, they worked well for me. Rotor color looks good, no pulse, no fade issues. I've got 8mm front pad thickness and 10mm rear remaining after seven sessions between the two days. As you suggest, I'll just swap new OEM pads in more often and hope that my rotors last longer. It's sooooooo nice to no longer have the constant squeal of track pads on the street.

This was my first time wearing a fire suit in hot weather, holy crap I must have drank a case of water and didn't piss once all weekend, LOL.

I had problems with my timing software and for the entire weekend was only able to record 4 laps in one of the hotter sessions. The fastest of those was a 2:02.5 lap, I was pleased considering the scorching weather. I suspect I ran faster laps in the cooler morning sessions, but Harry's Lap Timer just kept puking and rebooting, losing all data. I'll write a thread when I get a chance.

 

[VENOM V]

Todd,
You might want to consider starting a thread just covering your different brake set-ups, and experience with them. You're blazing a trail with the GTS brakes, and others will be following that could benefit from your experience. You could update the thread as you go.

Good idea, and I'd love to get some feedback from others.

Today I sanded off the pad deposits as much as possible (very small amount left), removed the pads to examine, checked for free movement of pads, and re-assembled. I noticed that almost all of the deposits were on the exterior rotor surface, with very little on the inside. I checked with a reputable Viper tech who suggested I not remove the rotors as the hat hardware could be damaged, so I wasn't able to sand the inside rotor faces, but again, there was very little deposits on them. Afterwards the brakes felt only ever so slightly better...still a little rough feeling and sounding. The tech suggested I try new pads, and since I can't get them before my next track day on Wed I'll just see how it goes with these. With any luck the pads will bed more evenly.

The OEM pads have ~2800 miles on them, including 2 light and 2 heavier track days, and there's still over 3/8" of pad thickness left out of maybe 1/2" thickness when new. I should be able to get another 3 track days out of them I would think.

Can't you remove the entire rotor assembly while keeping it assembled to the hat? I haven't done my own Viper brakes yet, but on my Camaro you unbolt the calipers and then the rotor comes right off. This way, you don't touch the hat hardware. As an aside, the Camaro has TTY (torque to yield) bolts that attach the calipers. They are one-time use, so if you remove and re install your calipers, you are supposed to use new caliper bolts every time. I don't know if that's the case with the Viper, but it would be smart to research this before re-using the caliper bolts.

And since you're still experiencing the rough feeling and sound, you may want to have a brake shop turn your rotors. A good brake guy could remove a very small amount and measure runout to ensure the rotors run true. If you have time before your next track event, it may be a good investment. I also believe that a good brake guy could carefully flatten the pads so that they will mate flat to your freshly turned disks. I'm not a brake expert, hopefully someone else can chime in to see if they agree.

Correction to previous posts: The track pads that I had trouble with are Brakeman 3 pads (new formulation), not Motoman pads. I tried to edit a couple of my earlier posts but they're too old.

 

[Bruce H.]

Todd,

The TA's rotors use one-time hat hardware so it was recommended not to take them off if I could avoid it. What I've found since sanding them is that under harder braking the brakes seem almost normal again feeling and sounding. Perhaps the rotors needed a bit of bedding material on them again. Still little noisy and slightly rough during lighter street use.

I saw the Viper tech at a club meeting on Saturday and he's now planning to replace the rotors and pads, but wasn't sure how quickly he'd receive either. I saw someone comment that the TA rotors can't be turned but don't know for sure. I'm sure I'm good for this Wednesday's track day, and the next 2 are at VIR 2 weeks later. Hopefully the new parts will be in by then. He says there are a lot of TA brake pads on B/O, which is odd since so few are tracking them, and wonders if that shortage might mean that they are waiting for a reformulated pad to be available. He says some are complaining about brake squeal, which would be caused by not using the pads hard enough.

Hey, maybe that's the cause of your squeal, and you just need to use them harder , lol!