11 GT3-Is this a tire balance issue?
12-25-2011, 10:22 PM
#16
Rennlist Member
Thread Starter
Anybody ever had improper brake bedding cause the slight steering wheel shimmy I mentioned in the opening post?
My car has slotted Brembo rotors. I just found this memo from Brembo explaining the bedding procedure.
NOTE: It is very important to follow proper brake bedding procedure following installation. This is necessary not only for optimum performance of the system, but also to avoid judder (vibration felt through brake and steering).
The discs are shipped with a thin zinc coating to prevent corrosion. Prior to beginning the bedding procedure, this plating must be removed from the braking surfaces by driving the car slowly (under 30 mph) and performing very light brake applications in order to remove the plating without generating heat. With too much heat or pedal pressure, this plating can be deposited unevenly on the disc and impregnated into the pad, further increasing the likelihood of judder. Once a visual inspection of the braking surface confirms that the plating has been removed, begin with the bedding procedure as specified below.
• Drive vehicle to remote area and perform at least 30 brake applications of 3 second duration. Use light/medium deceleration with varying starting speeds. Leave at least ½ mile between each brake application.
• The purpose of this procedure is to gradually increase the temperature in the components without thermal shock, and to mate the brake pad and disc friction surface.
• After the repeated stops, drive the vehicle for several miles with little or no braking in order to adequately cool the components.
• The system is now ready for normal use
NOTE: This entire procedure must be complete before driving the vehicle as normal. It is especially important that this procedure is completed before any extended same-speed driving is done (i.e. freeway travel). Failure to follow these instructions greatly increases the likelihood of judder development.
My car has slotted Brembo rotors. I just found this memo from Brembo explaining the bedding procedure.
NOTE: It is very important to follow proper brake bedding procedure following installation. This is necessary not only for optimum performance of the system, but also to avoid judder (vibration felt through brake and steering).
The discs are shipped with a thin zinc coating to prevent corrosion. Prior to beginning the bedding procedure, this plating must be removed from the braking surfaces by driving the car slowly (under 30 mph) and performing very light brake applications in order to remove the plating without generating heat. With too much heat or pedal pressure, this plating can be deposited unevenly on the disc and impregnated into the pad, further increasing the likelihood of judder. Once a visual inspection of the braking surface confirms that the plating has been removed, begin with the bedding procedure as specified below.
• Drive vehicle to remote area and perform at least 30 brake applications of 3 second duration. Use light/medium deceleration with varying starting speeds. Leave at least ½ mile between each brake application.
• The purpose of this procedure is to gradually increase the temperature in the components without thermal shock, and to mate the brake pad and disc friction surface.
• After the repeated stops, drive the vehicle for several miles with little or no braking in order to adequately cool the components.
• The system is now ready for normal use
NOTE: This entire procedure must be complete before driving the vehicle as normal. It is especially important that this procedure is completed before any extended same-speed driving is done (i.e. freeway travel). Failure to follow these instructions greatly increases the likelihood of judder development.
12-25-2011, 10:31 PM
#17
Race Director
Yes under braking. Just driving on the road no brakes and you feel a shimmy at a certain speed .... That is wheel balance.
