Brakepad fade mystery

[Max Rips]

I do a lot of canyon runs and after the first one, I realized that stock pads are not enough. So I bought Carbotech 1521 for the front and oh boy were they good. Even after a very hot session and them smoking they only needed a minute to cool off and be as good as before. So I thought there's room for improvement and ordered 2 piece Girodisc rotors for the front and a set of new 1521. It was the same pads that I loved and new rotors that have better cooling, so should be better right? Not in my case. Somehow the brakes started fading really quick and I could feel the smell of burning pads and I wasn't even going as hard as I usually do. So I am really confused. The only thing I changed is installed better rotors. I've been driving with the new rotors and pads for a while now and they still fade really bad almost on the second hard braking. Any ideas on why is that?

Sponsored

 

[Ewheels]

When you say "fade" is it hard pedal no brake or soft pedal no brake?
Your fluid may be boiled.

Did you bed everything in correctly?

Is traction control kicking in? That'll cook the rear fluid quickly.

 

[Max Rips]

It's soft pedal no brake. The fluid is Castrol racing. Traction control is not kicking in. I bed it as good as I could on the street. The same way I did with the first set.

 

[Ewheels]

It's soft pedal no brake.

That's boiled fluid then. As to how, there could be a number of reasons. I would bleed the brakes and look for air bubbles and note the color comparing the front vs the rear. That will give you more information.

 

[Max Rips]

Thanks, I'll try and see if it fixes the issue.

 

[thelostotter]

Might be a dumb question but are the rotors on the correct side? Unlike the stock rotors, the Girodisc are directional.

If yes, it could be an artifact of the the two piece rotor having less mass. They will heat up and cool down faster than the heavy stock rotors. Not sure what kind of canyon runs you are doing but if you don't have any extended periods of sustained speeds the two piece rotors could be running hotter than stock. This is speculation, I'm amazed you were able to boil fluid on the street.

 

[Max Rips]

The rotors are on the correct side according to the supplied manual.

The weird thing is - even if I do just a couple of hard braking from say 130, the brakes fade right away. I've never had this issue with the stock rotors. At first, I thought the rotors make the pad run too cool and it can't get to its working temperature but the smell means the pads are actually overheating.

 

[Specracer]

Most if not all pads that advertise "low dust" are not going to survive heavy use. The pad is simply not able to handle the heat you are asking it to withstand. This is from Carbotech's website:

"Carbotech™ 1521™ is NOT recommended for ANY track use". If your getting them that hot, your basically getting into "track use".

Change to a more durable pad, suitable for track, but also street use. I have the most experience with the Padgid Yellow. I tried 2 others before getting to the Yellows, that did not work (Im an experienced road racer).

EDIT, and to answer your question as to why the issue is new? I might suggest that your driving skills are improving, and your pushing harder, as your skills improve. You might want to consider getting to some HPDE's vs the streets.

 

[Max Rips]

Thanks for the input I'll look into Padgid

 

[Flyhalf]

A soft pedal.could.be sign of some air inside the system. A good bleed can help for sure.
Do you have a pic of girodisc?

 

[Max Rips]

 

[VictorH]

Thanks for the input I'll look into Padgid

I'll second the air in the system explanation too. Get a good brake bleed all around and see if you get a nice pedal back.
Your rotors look fine.
I ran Pagid on a previous vehicle and currently run Pagid RSL-29 pads all around currently on my Mach 1. They are excellent pads but are getting really expensive now.
You might also consider Cobalt Friction XR-2/XR-3 pads.
Ferrado makes good pads too but I've never run them. All three of these excellent, top-end race type pads that with really hard use will not let you down.

 

[Max Rips]

I'll second the air in the system explanation too. Get a good brake bleed all around and see if you get a nice pedal back.
Your rotors look fine.
I ran Pagid on a previous vehicle and currently run Pagid RSL-29 pads all around currently on my Mach 1. They are excellent pads but are getting really expensive now.
You might also consider Cobalt Friction XR-2/XR-3 pads.
Ferrado makes good pads too but I've never run them. All three of these excellent, top-end race type pads that with really hard use will not let you down.

Do Pagid or Cobalt dust a lot?

 

[VictorH]

If you use them as they are designed, YES a lot. But, I'm talking about real track use. I just finished a two day track event. I was running the car hard (advanced group) and yes you get a lot of brake dust, but we're talking about hauling a really heavy car down from well over 100 mph speeds, lap after lap.

 

[NightmareMoon]

Those carbotechs are street pads and will probably glaze pretty bad if you’re doing hard stops from 130.

If the oedal goes spongy, its the brake fluid. If the pedal is firm, its your pad selection.

IMHO that carbotech pad compound will glaze easier than the stock brembo pads, but they’re fine for most street use (bombing canyons is one of the exceptions)

Sponsored