Glazed Brake Pads?
03-17-2009, 01:16 PM
#1
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Thread Starter
Glazed Brake Pads?
So I did my first track event last fall and had a blast. The sun coming out here in the frozen north has me thinking about this season. Before the event I gravity bled my brake system with ATE blue. Seemed that after the event the brakes seemed to have less bite than before and during. I was aggressive with them and the instructor recommended upgrading brakes as a first performance step. Everything is stock as of now. Did I glaze the pads? How do I check that? Not likely I boiled the fluid is it? Have new pads here if needed but the old ones have life left as far as pad material. Can I clean them up? I did not use the parking brake and had plenty of time between sessions for the system to cool. Planning on rotors and carbotechs soon but probably have more to learn first. Sorry for the long post and thanks for the input!
03-17-2009, 03:29 PM
#2
Registered User
when you boil the fluid, you will not able to get brake back without flushing the old junk out, if you only have a temp. braking issue(something that go back to normal after a 15minute sit or pumping the brake a few time), it's most likely to be a glazed pad or faded brake
glazed pad happens when the operation temp reach higher than the designed operation range, you can reuse the pad most of the time(unlike boiled juice)
before anyone said anything about slotted rotor: they don't work
ate dot4 PF or Carbotechs will do, a thin or worn down rotor will also hold less thermal mass, you can achieve the same with a drilled/dimpled rotors
glazed pad happens when the operation temp reach higher than the designed operation range, you can reuse the pad most of the time(unlike boiled juice)
before anyone said anything about slotted rotor: they don't work
ate dot4 PF or Carbotechs will do, a thin or worn down rotor will also hold less thermal mass, you can achieve the same with a drilled/dimpled rotors
03-17-2009, 05:47 PM
#3
^^^Actually cooked fluid can come back, there have been people who have not taken the warning of a soft pedal after a session and gone back out without bleeding the fluid. The fluid will feel fine for a while, but will boil at a lower temp than before and go bad again.
But that it does not sound like what the OP described, sounds like a pad issue. Besides with the ATE fluid and stock pads, my bet would be that the pads would fade before the fluid would boil.
Glazing the pads and brake fade are not the same thing though; however, I can see brake fade causing glazed pads. In general brake fade is from exceeding the optimal functional temp. of the pad, once you hit that temp. the pad will not function nearly as well. I would guess that the optimal temp. for stock pads is relatively low, which is why IMO you would have very noticeable fade before you would hit a temp. that would boil ATE fluid.
I would change the pads, IMO the stock pads are not that great. They dust a TON, I cannot imagine the amount of dust after an event and they really don't stop that well for the amount of dust they generate.
When at the track I make a habit to do a couple of things to minimize issues with the braking system (mostly the pads and rotors):
-try to do a cool down lap by using as little brake as possible
-try not to stop for any extended period of time when heading into the paddock (this is why the general rule in most paddock are that the cars have the right of way over pedestrians).
-DO NOT USE THE PARKING BRAKE WHEN YOU PARK YOUR CAR TRY TO PARK ON A FLAT SPOT WITH BLOCKS
But that it does not sound like what the OP described, sounds like a pad issue. Besides with the ATE fluid and stock pads, my bet would be that the pads would fade before the fluid would boil.
Glazing the pads and brake fade are not the same thing though; however, I can see brake fade causing glazed pads. In general brake fade is from exceeding the optimal functional temp. of the pad, once you hit that temp. the pad will not function nearly as well. I would guess that the optimal temp. for stock pads is relatively low, which is why IMO you would have very noticeable fade before you would hit a temp. that would boil ATE fluid.
I would change the pads, IMO the stock pads are not that great. They dust a TON, I cannot imagine the amount of dust after an event and they really don't stop that well for the amount of dust they generate.
When at the track I make a habit to do a couple of things to minimize issues with the braking system (mostly the pads and rotors):
-try to do a cool down lap by using as little brake as possible
-try not to stop for any extended period of time when heading into the paddock (this is why the general rule in most paddock are that the cars have the right of way over pedestrians).
-DO NOT USE THE PARKING BRAKE WHEN YOU PARK YOUR CAR TRY TO PARK ON A FLAT SPOT WITH BLOCKS
03-17-2009, 06:07 PM
#4
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Originally Posted by pgss2k,Mar 17 2009, 05:16 PM
So I did my first track event last fall and had a blast. The sun coming out here in the frozen north has me thinking about this season. Before the event I gravity bled my brake system with ATE blue. Seemed that after the event the brakes seemed to have less bite than before and during. I was aggressive with them and the instructor recommended upgrading brakes as a first performance step. Everything is stock as of now. Did I glaze the pads? How do I check that? Not likely I boiled the fluid is it? Have new pads here if needed but the old ones have life left as far as pad material. Can I clean them up? I did not use the parking brake and had plenty of time between sessions for the system to cool. Planning on rotors and carbotechs soon but probably have more to learn first. Sorry for the long post and thanks for the input!
https://www.s2ki.com/forums/index.php?showt...&#entry14600998
The only brake upgrades you need for now is a racing pads and fluids
.
03-18-2009, 03:52 AM
#5
Registered User
Thread Starter
Thanks for chiming in. So it seems unlikely that I boiled the fluid as it would be hard to get enough temp out of stock pads right? Seems safe to assume that I can swap the old stock pads for new as daily drivers, turn the rotrs and I guess for track days I will be getting a dedicated set of pads and rotors. The carbotechs seem to want new or reconditioned rotors XP10/8. Easy enough to swap just need to get there early. Does any one know if there is a bedding in procedure for stock pads. I know there is one for the carbotechs. How many events is ATE fluid good for?
03-18-2009, 08:15 AM
#6
Most have found that the OEM pads subjected to the heat of track use will recover some of their friction level but will never be fully effective again. There is no need to go through a bedding procedure with OEM (street) pads.
Fluid does not deteriorate with the heat of track use, it is the time of air exposure that hurts the fluid so it is subject to boiling as it absorbs moisture. A flush every year or two is usually all that is needed.
Use track pads for track and street pads for street. Using the wrong equipment in any environment renders the car less effective and enjoyable.
Improved air flow for cooling the front rotors along with track pads solves the majority of track braking issues with this car.
Fluid does not deteriorate with the heat of track use, it is the time of air exposure that hurts the fluid so it is subject to boiling as it absorbs moisture. A flush every year or two is usually all that is needed.
Use track pads for track and street pads for street. Using the wrong equipment in any environment renders the car less effective and enjoyable.
Improved air flow for cooling the front rotors along with track pads solves the majority of track braking issues with this car.
03-18-2009, 03:40 PM
#7
Registered User
Originally Posted by bgoetz,Mar 17 2009, 05:47 PM
^^^Actually cooked fluid can come back, there have been people who have not taken the warning of a soft pedal after a session and gone back out without bleeding the fluid. The fluid will feel fine for a while, but will boil at a lower temp than before and go bad again.
But that it does not sound like what the OP described, sounds like a pad issue. Besides with the ATE fluid and stock pads, my bet would be that the pads would fade before the fluid would boil.
Glazing the pads and brake fade are not the same thing though; however, I can see brake fade causing glazed pads. In general brake fade is from exceeding the optimal functional temp. of the pad, once you hit that temp. the pad will not function nearly as well. I would guess that the optimal temp. for stock pads is relatively low, which is why IMO you would have very noticeable fade before you would hit a temp. that would boil ATE fluid.
I would change the pads, IMO the stock pads are not that great. They dust a TON, I cannot imagine the amount of dust after an event and they really don't stop that well for the amount of dust they generate.
When at the track I make a habit to do a couple of things to minimize issues with the braking system (mostly the pads and rotors):
-try to do a cool down lap by using as little brake as possible
-try not to stop for any extended period of time when heading into the paddock (this is why the general rule in most paddock are that the cars have the right of way over pedestrians).
-DO NOT USE THE PARKING BRAKE WHEN YOU PARK YOUR CAR TRY TO PARK ON A FLAT SPOT WITH BLOCKS
But that it does not sound like what the OP described, sounds like a pad issue. Besides with the ATE fluid and stock pads, my bet would be that the pads would fade before the fluid would boil.
Glazing the pads and brake fade are not the same thing though; however, I can see brake fade causing glazed pads. In general brake fade is from exceeding the optimal functional temp. of the pad, once you hit that temp. the pad will not function nearly as well. I would guess that the optimal temp. for stock pads is relatively low, which is why IMO you would have very noticeable fade before you would hit a temp. that would boil ATE fluid.
I would change the pads, IMO the stock pads are not that great. They dust a TON, I cannot imagine the amount of dust after an event and they really don't stop that well for the amount of dust they generate.
When at the track I make a habit to do a couple of things to minimize issues with the braking system (mostly the pads and rotors):
-try to do a cool down lap by using as little brake as possible
-try not to stop for any extended period of time when heading into the paddock (this is why the general rule in most paddock are that the cars have the right of way over pedestrians).
-DO NOT USE THE PARKING BRAKE WHEN YOU PARK YOUR CAR TRY TO PARK ON A FLAT SPOT WITH BLOCKS
once they are boiled they will recover once they are cooled down but they will boil again at much much lower temp vs new fluid, at this point you will need to fluid it out.
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03-18-2009, 04:08 PM
#8
Originally Posted by iam7head,Mar 18 2009, 06:40 PM
Hi, yes and no
once they are boiled they will recover once they are cooled down but they will boil again at much much lower temp vs new fluid, at this point you will need to fluid it out.
once they are boiled they will recover once they are cooled down but they will boil again at much much lower temp vs new fluid, at this point you will need to fluid it out.
03-18-2009, 04:28 PM
#9
Originally Posted by cdelena,Mar 18 2009, 11:15 AM
Most have found that the OEM pads subjected to the heat of track use will recover some of their friction level but will never be fully effective again. There is no need to go through a bedding procedure with OEM (street) pads.
Fluid does not deteriorate with the heat of track use, it is the time of air exposure that hurts the fluid so it is subject to boiling as it absorbs moisture. A flush every year or two is usually all that is needed.
Use track pads for track and street pads for street. Using the wrong equipment in any environment renders the car less effective and enjoyable.
Improved air flow for cooling the front rotors along with track pads solves the majority of track braking issues with this car.
Fluid does not deteriorate with the heat of track use, it is the time of air exposure that hurts the fluid so it is subject to boiling as it absorbs moisture. A flush every year or two is usually all that is needed.
Use track pads for track and street pads for street. Using the wrong equipment in any environment renders the car less effective and enjoyable.
Improved air flow for cooling the front rotors along with track pads solves the majority of track braking issues with this car.
Track time destroys fluids from the extream heat. Why do you think fluids have boiling points and the better the fluid (i.e. fluid designed for the track) has a higher boiling point. There are a ton of race crews that completely bleed fluid after every single session due to this. You can also buy some super expensive fluids (Castrol SRF) that have insanely high boiling points, just for the insane heat of track use, just so it does not go bad while the car is on the track. AGAIN HEAT FROM THE TRACK DOES EFFECT FLUIDS. If you don't believe me ask the tons of people who have boiled perfectly good fluid and had the brake go right to the floor.
Second you should bed any brake pad, just so you don't end up glazing new pads. With a pad that has a bedding instruction I would follow that. With pads that don't I would take them out and do a couple moderate stops from 30mph or so getting right off the brakes afterward (i.e. don't do it so you need to sit at a light with the brakes on), do the same except do harder stops again stay off the brakes afterward. Repeat except from 60mph or so, then let the brakes completely cool before using them. With track specific pads this gets a bit tricky to do, sometimes you can cruise around the roadways/paddock giving a bit of quick brake and then bring them back and let them cool.
OP if you do change to race pads just be aware that you now have a better chance of your fluid boiling and your brake heading to the floor. Not saying you should not change pads, infact you should, you just need to be aware that that can happen. And it is ALOT different than some brake fade, which can be scary enough.
03-18-2009, 05:36 PM
#10
Been there, done that.
I think you are experiencing what I call "right after track day brake underuse". When you are tracking, temps go up (~400-550 deg.) and pedal pressure goes really high, allowing you to feel 100% of the brakes power. Stock brakes will fade at the 550 deg. mark.
When you hit the street, the brakes work a lot cooler, usually anywhere between 120-300 deg. and the amount of pedal pressure you apply is a lot less, resulting in an inherently lower brake force feel. I don't have a graph showing the correlation between a stock pad's friction coeficient and temperature, but I am confident it is at it's highest between really warm (>200 deg.) and really hot (~350 deg. or maybe higher), before it starts going down again.
So, if there is no vibration when you apply the brakes, they should be fine. I would not worry about it.
I think you are experiencing what I call "right after track day brake underuse". When you are tracking, temps go up (~400-550 deg.) and pedal pressure goes really high, allowing you to feel 100% of the brakes power. Stock brakes will fade at the 550 deg. mark.
When you hit the street, the brakes work a lot cooler, usually anywhere between 120-300 deg. and the amount of pedal pressure you apply is a lot less, resulting in an inherently lower brake force feel. I don't have a graph showing the correlation between a stock pad's friction coeficient and temperature, but I am confident it is at it's highest between really warm (>200 deg.) and really hot (~350 deg. or maybe higher), before it starts going down again.
So, if there is no vibration when you apply the brakes, they should be fine. I would not worry about it.