misc brake questions
Thread Starter
Racer
Joined: Jul 2004
Posts: 444
Likes: 0
From: Dallas TX
misc brake questions
I recently took my Z06 to it's first autocross and I noticed that the brake pedal seems a little soft and has a bit more travel to it. The fluid in the reservoir is down but not below the min marking. From what I've read, getting the brakes really hot can cause the fluid to boil out and expand. When things cool off, is it pulling air into the system? Is the appropriate fix just topping off the reservoir, bleeding the brakes, or changing the fluid? Is there any way of preventing this from happening?
The pads also dust like crazy and I looked into getting some low dust EBC green pads. The mechanic I typically go to said that I need to also have the rotors machined whenever pads are replaced. Is this true?
The pads also dust like crazy and I looked into getting some low dust EBC green pads. The mechanic I typically go to said that I need to also have the rotors machined whenever pads are replaced. Is this true?
Tech Contributor
Joined: Oct 1999
Posts: 41,057
Likes: 9,817
From: Charlotte, NC (formerly Endicott, NY)
Even with 10 year old fluid you shouldn't have gotten the brakes hot enough to boil the fluid at an autocross. You may have tapered pads which can lead to a long pedal. If the pads have a lot of miles on them you may need to change them.
As for turning rotors I never do it. If they aren't damaged I do not turn them (even when changing from one brand of pad to another) and if they are damaged I just buy new ones. The cost of new ones is a little more than what you would pay for having them turned.
If you want to have aggressive pads that will slow your car quickly at an autocross do not go with the EBC pads. Stick with the stock pads or an equivalent aftermarket pad. The EBC pads are for show not go.
Bill
As for turning rotors I never do it. If they aren't damaged I do not turn them (even when changing from one brand of pad to another) and if they are damaged I just buy new ones. The cost of new ones is a little more than what you would pay for having them turned.
If you want to have aggressive pads that will slow your car quickly at an autocross do not go with the EBC pads. Stick with the stock pads or an equivalent aftermarket pad. The EBC pads are for show not go.
Bill
Thread Starter
Racer
Joined: Jul 2004
Posts: 444
Likes: 0
From: Dallas TX
The car has 32k miles on it and I believe they are the original pads. I noticed the pedal getting soft towards the end of the day after I did 3 back to back runs.
Is there a good pad out there that is low dust? I'm willing to give up a little bit of braking performance for those very few times I would race versus the mess it makes every day.
Is there a good pad out there that is low dust? I'm willing to give up a little bit of braking performance for those very few times I would race versus the mess it makes every day.
Team Owner
Joined: Sep 2003
Posts: 43,084
Likes: 33
From: Raleigh / Rolesville NC
No you must blead the brakes AT EACH caliper. Replace with DOT 4 brake fluid.
When you put brake fluid into the MC do not fill more then 3/4 full as brake fluid will expand when hot
Brake fluid should be replace at a min of once a year. No matter what the manual says. If you AUTO-X then before and AFTER each event weekend
When you put brake fluid into the MC do not fill more then 3/4 full as brake fluid will expand when hot
Brake fluid should be replace at a min of once a year. No matter what the manual says. If you AUTO-X then before and AFTER each event weekend
Advanced
Joined: Apr 2007
Posts: 50
Likes: 0
From: Sydney
If you plan on doing a few auto-x days then it may be a good idea to fit some braided lines on the front and replace the fluid with a decent quality DOT 5.1 fluid. When the brake system heats up the OEM brake lines can expand and result in a less responsive pedal. When your pads wear out a set of carbon metallic pads like Hawk HPS will handle slightly higher tamps than stock. Never have been a fan of EBC's.
After an Auto-X day it is a good idea to bleed a few ounces of fluid out of the calipers just to freshen up the fluid around the pistons which are exposed to the most heat. Top up the resevior and away you go.
After an Auto-X day it is a good idea to bleed a few ounces of fluid out of the calipers just to freshen up the fluid around the pistons which are exposed to the most heat. Top up the resevior and away you go.
