What happened to my brakes??? W/Pics
05-05-09, 12:43 PM
#1
What happened to my brakes??? W/Pics
Hey all,
Wanted to get some more experienced opinions on my brake situation.
From the situation, can anyone tell me if I boiled the fluid or glazed the pads? or both?
And has anyone seen the same wear pattern as seen on my brake pads?
So I took my 87 TII to Thunderhill in Willows, CA for a HPDE 1 event and ran four 20-minute sessions with half hour to 2 hour breaks in between. During the last session, about 17 min in, I lost my brakes on track. Pedal went to the floor and car didn't slow at all. E-brake also did nothing. Cruised the rest of the lap to let the brakes cool, but even after getting back to the pit, I could probably have stopped faster if I opened the door and dragged my foot on the ground Flintstones style. After changing my pants, came back half an hour later and the brakes felt the same as before, but *slightly* more spongy than before.
Hardware: Cross-drilled and slotted vented rotors, F/R. I know, drilled rotors are frowned upon for structural reasons, but I think slots are valid for removing hot pad material/dust better than blanks. I just never thought I would be pushing the car this hard in the short sessions.
EBC Redstuff pads front, EBC Greenstuff pads rear.
Unknown brand DOT4 brake fluid, pretty clean, 1 year old.
Hankook RS2 tires. Stock dust shields in place.
*The brake rotor groove came later. So ignore it for now.
The dark area on the pads seem glazed to me but I have not had much experience with this.
The gray areas on the pad are lower (less than .1mm) and more'chunked' than the dark sections. They also line up with the cross drilled holes in the rotor. Also, the closeup pic of the pad shows a crack that developed and I'm not sure if that is important or not.
So this brings up two interesting questions:
Since my rotors were slotted and drilled, are the holes working better than the slots to clear pad material?
Is the gray area running cooler? If so, the only difference between the black/gray areas is that the area running over the drilled holes is running cooler.
I know drilled/slotted has been beaten to death, but I just want to evaluate what I'm seeing.
Thanks in advance.
Wanted to get some more experienced opinions on my brake situation.
From the situation, can anyone tell me if I boiled the fluid or glazed the pads? or both?
And has anyone seen the same wear pattern as seen on my brake pads?
So I took my 87 TII to Thunderhill in Willows, CA for a HPDE 1 event and ran four 20-minute sessions with half hour to 2 hour breaks in between. During the last session, about 17 min in, I lost my brakes on track. Pedal went to the floor and car didn't slow at all. E-brake also did nothing. Cruised the rest of the lap to let the brakes cool, but even after getting back to the pit, I could probably have stopped faster if I opened the door and dragged my foot on the ground Flintstones style. After changing my pants, came back half an hour later and the brakes felt the same as before, but *slightly* more spongy than before.
Hardware: Cross-drilled and slotted vented rotors, F/R. I know, drilled rotors are frowned upon for structural reasons, but I think slots are valid for removing hot pad material/dust better than blanks. I just never thought I would be pushing the car this hard in the short sessions.
EBC Redstuff pads front, EBC Greenstuff pads rear.
Unknown brand DOT4 brake fluid, pretty clean, 1 year old.
Hankook RS2 tires. Stock dust shields in place.
*The brake rotor groove came later. So ignore it for now.
The dark area on the pads seem glazed to me but I have not had much experience with this.
The gray areas on the pad are lower (less than .1mm) and more'chunked' than the dark sections. They also line up with the cross drilled holes in the rotor. Also, the closeup pic of the pad shows a crack that developed and I'm not sure if that is important or not.
So this brings up two interesting questions:
Since my rotors were slotted and drilled, are the holes working better than the slots to clear pad material?
Is the gray area running cooler? If so, the only difference between the black/gray areas is that the area running over the drilled holes is running cooler.
I know drilled/slotted has been beaten to death, but I just want to evaluate what I'm seeing.
Thanks in advance.
Last edited by RXSpeed16; 05-05-09 at 12:49 PM. Reason: picture posting noob
05-05-09, 02:16 PM
#2
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Wow, hammered pads
Were you the red TII with black spokes at the April 25th/26th event? I was the red 3rd gen.
Yes, your pads are glazed/hammered.
I would move to solid rotors for better heat dissipation/absorbtion. I would get yourself some ATE Super Blue and Red brake fluid and purge your whole system. I would examine your hoses to see if they are old and 'expanding' when you activate the brakes.
I would also get some brake temp indicator tape for the next time you go out, so you can monitor your brake temps.
The Hankook's are a 200 tread wear tire, which isn't sticky enough to warrant the kind of grip from braking that would have overpowered these pads. The fact that the glazing matches up with the cross drilled holes is a possible indicator that the holes are not well chamfered and may be chewing up the pads or overheating them. Another possiblility is your master cylinder, particularly the tipping valve. If you have an old master, there is a chance the tipping valve isn't releaseing the brakes, so they stay 'on' slightly and cause drag and heat things up. Had one fail on my old Triumph and the brakes would eventually lock up because the valve would not release.
Folks not real happy with the EBC Redstuff pad wear on Tirerack:
http://www.tirerack.com/brakes/brake...uff+brake+pads
You've got some investigating to do. Is this the same on all sides, or just one particular caliper? If not uniform, then the caliper itself could be sticking.
You've got lots to look into. I just installed a new MC on my RX7, purged the whole system with ATE Super Blue, and had tight brakes all the way with Porterfield R-4S pads and slotted rotors front and back. Used up about half the pads, will switch to the R-4 track pad for Infineon in June. You might want to consider the Porterfields, I've had great luck with them.
Beast
Yes, your pads are glazed/hammered.
I would move to solid rotors for better heat dissipation/absorbtion. I would get yourself some ATE Super Blue and Red brake fluid and purge your whole system. I would examine your hoses to see if they are old and 'expanding' when you activate the brakes.
I would also get some brake temp indicator tape for the next time you go out, so you can monitor your brake temps.
The Hankook's are a 200 tread wear tire, which isn't sticky enough to warrant the kind of grip from braking that would have overpowered these pads. The fact that the glazing matches up with the cross drilled holes is a possible indicator that the holes are not well chamfered and may be chewing up the pads or overheating them. Another possiblility is your master cylinder, particularly the tipping valve. If you have an old master, there is a chance the tipping valve isn't releaseing the brakes, so they stay 'on' slightly and cause drag and heat things up. Had one fail on my old Triumph and the brakes would eventually lock up because the valve would not release.
Folks not real happy with the EBC Redstuff pad wear on Tirerack:
http://www.tirerack.com/brakes/brake...uff+brake+pads
You've got some investigating to do. Is this the same on all sides, or just one particular caliper? If not uniform, then the caliper itself could be sticking.
You've got lots to look into. I just installed a new MC on my RX7, purged the whole system with ATE Super Blue, and had tight brakes all the way with Porterfield R-4S pads and slotted rotors front and back. Used up about half the pads, will switch to the R-4 track pad for Infineon in June. You might want to consider the Porterfields, I've had great luck with them.
Beast
05-05-09, 04:50 PM
#3
Hey Beast,
Thanks for the info. You are correct on the car/event. I was wondering if you are on here.
Where can I find the temperature monitoring tape?
I agree, I don't think I was running hard enough to cause these pads to fail given their suggested usage. Yet I seem to have destroyed them nonetheless.
Both sets of front pads looked like this with the same striping pattern. I haven't removed the rears yet, but hopefully I can check it some time soon. So I don't think it's an individual caliper issue. In the mean time, I have already replaced the rubber lines with stainless ones and flushed with Valvoline DOT 3/4. Probably gonna step up to super blue/amber next time I bleed it. It made a world of difference in pedal feel already but not gonna stop there.
I have a set of blank rotors that I'll probably get turned and have dedicated track pads and rotors. Just a bit torn on pad choice right now. Lookin at Hawk blues, porterfields, and carbotech's since the spec miata guys swear by em. Porterfields seem to be the only ones willing to publish friction coefficient vs temp graphs. Just too many options.
Most likely, I'll see ya out there at Infineon in June.
Thanks for the info. You are correct on the car/event. I was wondering if you are on here.
Where can I find the temperature monitoring tape?
I agree, I don't think I was running hard enough to cause these pads to fail given their suggested usage. Yet I seem to have destroyed them nonetheless.
Both sets of front pads looked like this with the same striping pattern. I haven't removed the rears yet, but hopefully I can check it some time soon. So I don't think it's an individual caliper issue. In the mean time, I have already replaced the rubber lines with stainless ones and flushed with Valvoline DOT 3/4. Probably gonna step up to super blue/amber next time I bleed it. It made a world of difference in pedal feel already but not gonna stop there.
I have a set of blank rotors that I'll probably get turned and have dedicated track pads and rotors. Just a bit torn on pad choice right now. Lookin at Hawk blues, porterfields, and carbotech's since the spec miata guys swear by em. Porterfields seem to be the only ones willing to publish friction coefficient vs temp graphs. Just too many options.
Most likely, I'll see ya out there at Infineon in June.
05-05-09, 05:40 PM
#4
If you are running HPDE 1, stick with a pad that is easier to drive on - such as the Porterfields or Carbos or some of the less aggressive Hawk pads like Blacks or HT10s or HP+. The Blues are pretty extreme and wears the rotors alot. Even the HT10s take some effort to learn to drive on them.
05-05-09, 05:40 PM
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05-05-09, 08:05 PM
#6
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Brake temp indicator strips
http://www.apracing.com/info/info.as...emperatures_44
You can use paint or strips.
http://www.hrpworld.com/index.cfm?fo...action=product
I have not yet looked at my Porterfield r-4s pads (I plan on taking them off and putting on the full race R-4 set when I order and mount my new tires, probably going BRGR1s). However, just sighting them through the wheels, it looks like they are down to about half, maybe 2/8th of an inch of 'groove' showing in the middle on the fronts. That is from two events, both two day, and in HPDE1/2 where I wasn't really on the brakes too hard, more coasting due to traffic.
When I put on the new tires with treadwear of 40 vs. the 280 wear T1-S, I'm going to heat those brakes up
I was amazed at the bite PJ got on his M3 in HPDE 4 using Hawk Blues....and also at the amount of material on his wheels. Dusty devils.
I used Porterfields R-4s for the street and they were wonderful.
If you have a dial gauge that can measure run-out, you should use it to see if the rotors also warped, again an indicator of heat....or cheap materials. You never know with rotors....I've bought some pretty lousy ones in the past. The Brembos I have now are good, and I'd really like to use Racing Brakes two-piece units once these rotors are done.
I think you have to ditch these components, go with non-drilled rotors and new pads, and then see if this recurs.
You can use paint or strips.
http://www.hrpworld.com/index.cfm?fo...action=product
I have not yet looked at my Porterfield r-4s pads (I plan on taking them off and putting on the full race R-4 set when I order and mount my new tires, probably going BRGR1s). However, just sighting them through the wheels, it looks like they are down to about half, maybe 2/8th of an inch of 'groove' showing in the middle on the fronts. That is from two events, both two day, and in HPDE1/2 where I wasn't really on the brakes too hard, more coasting due to traffic.
When I put on the new tires with treadwear of 40 vs. the 280 wear T1-S, I'm going to heat those brakes up
I was amazed at the bite PJ got on his M3 in HPDE 4 using Hawk Blues....and also at the amount of material on his wheels. Dusty devils.
I used Porterfields R-4s for the street and they were wonderful.
If you have a dial gauge that can measure run-out, you should use it to see if the rotors also warped, again an indicator of heat....or cheap materials. You never know with rotors....I've bought some pretty lousy ones in the past. The Brembos I have now are good, and I'd really like to use Racing Brakes two-piece units once these rotors are done.
I think you have to ditch these components, go with non-drilled rotors and new pads, and then see if this recurs.
05-05-09, 09:24 PM
#7
Before I start this, 1 year old fluid is too old if you are going to do track days.
This was a driver issue, and not necessarily a brake issue. You were using too little brake for too long of time in the corners. This builds up too much heat in the pads/rotors that can't be bled off on the straights. Things got so hot you boiled your old and compromised fluid and lost all remaining brake feel. The bubbles in your caliper, are still in there giving you the spongy feel.
I know you don't have ABS, but you want to use the brakes as hard as you can, for the shortest period of time you can. That will help you avoid situations like this.
Ditch the crappy drilled/slotted rotors. and replace them with BREMBO replacement blanks. You don't need race pads if you aren't running R compound tires.
Do a full brake fluid flush with quality fluid. You don't need Motul or Castrol SRF, or anything extremely expensive. Just get Super Blue, or something with around a 500 degree dry boiling point. Depending on how you drive you car on the street, you may want to step up to a slightly more agressive pad. Be aware if you do this you will see a degredation in brake performance for the first few stops, or if it is cold and you are cruising on the highway.
I run Hawk HP+ pads with street tires on the track. They are GREAT, but they dust a bit more than usual and are a little whiny when coming to a stop. Niether of these issues bother me. They are a bit soft for the first few stops but they are fine when they build a little heat.. They are cheap, and fairly easy on the rotors. If you think HP+ might be too agressive for you, try Hawk HPS. I think they are slightly more agressive than EBC greens. The Hawk pads are very cheap compared to other brands. Carbotechs are very good if you are willing to spend more money. With the Hankook RS2s you have I would say get the HP+ pads and you will be happy with them on and off the track.
When you run R coupounds and race pads you can evaluate the need for slots in your rotors. By then you will know enough to know they are not needed.
This was a driver issue, and not necessarily a brake issue. You were using too little brake for too long of time in the corners. This builds up too much heat in the pads/rotors that can't be bled off on the straights. Things got so hot you boiled your old and compromised fluid and lost all remaining brake feel. The bubbles in your caliper, are still in there giving you the spongy feel.
I know you don't have ABS, but you want to use the brakes as hard as you can, for the shortest period of time you can. That will help you avoid situations like this.
Ditch the crappy drilled/slotted rotors. and replace them with BREMBO replacement blanks. You don't need race pads if you aren't running R compound tires.
Do a full brake fluid flush with quality fluid. You don't need Motul or Castrol SRF, or anything extremely expensive. Just get Super Blue, or something with around a 500 degree dry boiling point. Depending on how you drive you car on the street, you may want to step up to a slightly more agressive pad. Be aware if you do this you will see a degredation in brake performance for the first few stops, or if it is cold and you are cruising on the highway.
I run Hawk HP+ pads with street tires on the track. They are GREAT, but they dust a bit more than usual and are a little whiny when coming to a stop. Niether of these issues bother me. They are a bit soft for the first few stops but they are fine when they build a little heat.. They are cheap, and fairly easy on the rotors. If you think HP+ might be too agressive for you, try Hawk HPS. I think they are slightly more agressive than EBC greens. The Hawk pads are very cheap compared to other brands. Carbotechs are very good if you are willing to spend more money. With the Hankook RS2s you have I would say get the HP+ pads and you will be happy with them on and off the track.
When you run R coupounds and race pads you can evaluate the need for slots in your rotors. By then you will know enough to know they are not needed.
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05-06-09, 01:25 AM
#8
Thanks for the info guys. I appreciate your willingness to help a new guy safely get into track days. I'm currently running HPDE1 so I have a lot to learn and that would explain how I was able to ruin what should have been a perfectly capable pad.
Habu - btw that's what happens when you forget the lock washer on the brake caliper bolt. Turns out it is a through hole and the bolt is long enough to contact the rotor. Got almost a full rotation before I realized the screach was the rotor, not in my head. They came off the car and that is where they will stay.
Beast- Cool info on the temperature strips. Hopefully it'll give me a better idea of where I'm running. Sounds like you're gonna be ready to party at Infineon.
It's looking like the HP+'s will fit the bill well. I'd rather give up some braking power to ensure they don't fade or fail like last time. I'm not pushing the numbers that Beast is, so I'm sure I don't need the same setup. I plan to keep running street tires for the time being so that should limit how extreme the upgrades should be.
I'll be better prepared next time with fresh fluid, different pads & blank rotors.
Thanks again for all your suggestions. I'm sure it will save me a lot of time, money, and possibly bodywork next time I head out.
Habu - btw that's what happens when you forget the lock washer on the brake caliper bolt. Turns out it is a through hole and the bolt is long enough to contact the rotor. Got almost a full rotation before I realized the screach was the rotor, not in my head. They came off the car and that is where they will stay.
Beast- Cool info on the temperature strips. Hopefully it'll give me a better idea of where I'm running. Sounds like you're gonna be ready to party at Infineon.
It's looking like the HP+'s will fit the bill well. I'd rather give up some braking power to ensure they don't fade or fail like last time. I'm not pushing the numbers that Beast is, so I'm sure I don't need the same setup. I plan to keep running street tires for the time being so that should limit how extreme the upgrades should be.
I'll be better prepared next time with fresh fluid, different pads & blank rotors.
Thanks again for all your suggestions. I'm sure it will save me a lot of time, money, and possibly bodywork next time I head out.
05-07-09, 03:49 PM
#10
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[QUOTE=LargeOrangeFont;9184905
This was a driver issue, and not necessarily a brake issue. You were using too little brake for too long of time in the corners. This builds up too much heat in the pads/rotors that can't be bled off on the straights. Things got so hot you boiled your old and compromised fluid and lost all remaining brake feel. The bubbles in your caliper, are still in there giving you the spongy feel.
.[/QUOTE]
this is true, and might be what happened. the hard part is that in group 1/2 that is just how traffic is.
This was a driver issue, and not necessarily a brake issue. You were using too little brake for too long of time in the corners. This builds up too much heat in the pads/rotors that can't be bled off on the straights. Things got so hot you boiled your old and compromised fluid and lost all remaining brake feel. The bubbles in your caliper, are still in there giving you the spongy feel.
.[/QUOTE]
this is true, and might be what happened. the hard part is that in group 1/2 that is just how traffic is.
05-08-09, 12:52 PM
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Duct your brakes. The pedal to the floor is the key indicator. Way too much heat build up, probably boiled the fluid. The pads also look glazed, which easily comes when way over-temped.
-Trent
-Trent
05-11-09, 07:32 PM
#12
I ran a stock '86 GXL with Toyo RA1's (235/17's), coilovers, Hawk HP+ pads, stock rotors, with synthetic fluid a few years back at Thunderhill as well. After 1 session driving pretty hard chasing an E36 M3 (and all over his ***) (only 138hp but with 160K miles on the motor) I pulled off and the brakes were literally smoking for a few minutes and wouldn't have surprised me if they caught on fire.
Stock brakes even with upgraded pads will get hammered. If you plan to do a lot of track days some upgraded brakes would be a wise move. Coleman Racing has a 2nd kit that is reasonably priced and much better than stock for sure.
Stock brakes even with upgraded pads will get hammered. If you plan to do a lot of track days some upgraded brakes would be a wise move. Coleman Racing has a 2nd kit that is reasonably priced and much better than stock for sure.
05-11-09, 08:57 PM
#13
I ran a stock '86 GXL with Toyo RA1's (235/17's), coilovers, Hawk HP+ pads, stock rotors, with synthetic fluid a few years back at Thunderhill as well. After 1 session driving pretty hard chasing an E36 M3 (and all over his ***) (only 138hp but with 160K miles on the motor) I pulled off and the brakes were literally smoking for a few minutes and wouldn't have surprised me if they caught on fire.
Stock brakes even with upgraded pads will get hammered. If you plan to do a lot of track days some upgraded brakes would be a wise move. Coleman Racing has a 2nd kit that is reasonably priced and much better than stock for sure.
Stock brakes even with upgraded pads will get hammered. If you plan to do a lot of track days some upgraded brakes would be a wise move. Coleman Racing has a 2nd kit that is reasonably priced and much better than stock for sure.
95% of people don't really need a caliper upgrade for track days.
The Coleman kit is a very nice upgrade if you do indeed decide to upgrade.
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