Posted: Thu Apr 24, 2008 1:35 am Post subject: Is300 warped rotors - Proper rotor break in procedure
Bought used IS 300 a month ago - Love it. My immidiate issue is with the brakes. Previous owner installed front new rotors, callipers, and brake pads because during the test before we bought, upon braking from highway speeds, the steering wheel was vibrating.
Now everything works fine, including the application of the brakes (car stops normal, no problem), except that I hear sometimes (intermitently) knocking sound upon applying the brakes, and / or a squeky noise (both from the front), which is very annoying. The noise seems to come only after the car is warmed up.
Anyone can help diagnose the problem. I am new to cars as well, when it comes to troubleshooting.
Joined: Feb 18, 2003 Posts: 2349 Location: Tarzana CA
Posted: Thu Apr 24, 2008 5:09 am Post subject:
Allbrake pads must be bedded-in with the rotor they will be used against to maximize brake performance. The bedding-in process involves a gradual build up of heat in the rotors and pad compound. this process will lay down a thin layer of transfer film on to the rotor surface. Following the bed-in procedures provided by the manufacturer will assure a smooth, even layer of transfer film on the rotor and will minimize brake judder. Here are a few things to keep in mind when installing new rotors and pads:
When installing new pads, the rotors should be new or at least resurfaced to remove any transfer film from the previous set of brake pads.
It is critical that the installer clean any rust, scale, or debris from the hub mounting surface thoroughly and check it for excessive run-out with a dial indicator gauge before installing the rotor.
The new rotor should also be checked for excessive run-out using a dial indicator gauge before the caliper and pads are installed. If a rotor has excessive run-out of over .004" (.10mm) it should be replaced.
If your new rotor has excessive run-out, please contact our customer service department for a replacement rotor. Do not install and drive using the rotor! Rotor manufacturers will not warranty a used rotor for excessive run-out. Running with excessive run-out on the hub or rotor will cause vibration issues.
Failure to follow these procedures may result in brake judder, excessive noise, or other difficulties in bedding-in the new brake pads. The pads need a fresh surface to lay down an even transfer film. Residue from the previous pad compound on the surface or an irregular surface on a used rotor will cause the pads to grip-slip-grip-slip as they pass over the rotor surface under pressure. The resulting vibration will cause noise and telegraph vibrations through the suspension and steering wheel. This vibration is known as brake judder or brake shimmy. This is typically caused by an uneven transfer film on the rotor surface or an uneven surface on the rotor not allowing that transfer film to develop evenly. This is often misdiagnosed as a warped rotor.
Bedding-in new pads and rotors should be done carefully and slowly. Rapid heat build up in the brake system can lead to warped rotors and or glazed brake pads. Most brake pad compounds will take up to 300-400 miles to fully develop an even transfer film on the rotors. Following are the recommended bed-in procedures from each manufacturer:
AKEBONO
400 to 500 miles of moderate driving is recommended. Consumer should avoid heavy braking during this period.
ATE
400 to 500 miles of moderate driving is recommended. Consumer should avoid heavy braking during this period.
BREMBO Gran Turismo
In a safe area, apply brakes moderately from 60mph to 30mph and then drive approximately 1/2 mile to allow the brakes to cool. Repeat this procedure approximately 30 times.
HAWK
After installing new pads make 6 to 10 stops from approximately 35 mph with moderate pressure. Make an additional two to three hard stops from approximately 40 to 45 mph. Do not allow the vehicle to come to a complete stop.When completed with this process, park the vehicle and allow the brakes to cool completely before driving on them again. Do not engage the parking brake until after this cooling process is compete.
NOTE: Hawk racing pads (Blue, Black, HT-10, HT-12) may require a different bed-in procedure. Contact your sales specialists at The Tire Rack for racing application information.
KAZERA
Follow the brake pad manufacturer's recommended break-in procedure taking care not to produce excessive heat in the system. Avoid heavy braking for the first 400-500 miles.
POWER SLOT
Follow the brake pad manufacturer's recommended break-in procedure taking care not to produce excessive heat in the system. Avoid heavy braking for the first 400-500 miles.
SATISFIED
For Gransport GS6 Carbon Ceramic Pads �
Step 1: Make 10 stops from 30 mph (50 kph) down to about 10 mph (15 kph) using moderate braking pressure and allowing approximately 30 seconds between stops for cooling. Do not drag your pads during these stops. After the 10th stop, allow 15 minutes for your braking system to cool down.
Step 2: Make 5 consecutive stops from 50 mph (80 kph) down to 10 mph (15 kph). After the 5th stop, allow your braking system to cool for approximately 30 minutes. This completes the break-in of your pads to the rotor surface.
During Steps 1 & 2, a de-gassing process occurs which may produce an odor coming from your pads as they complete the break-in cycle. This odor is normal and is part of the process your pads must go through to achieve their ultimate level of performance. The odor will go away after allowing your braking system to cool for approximately 30 minutes.
As with any new set of pads, do not tow a trailer or do any hauling during the break-in period.
Full seating of your new brake pads normally occurs within 1,000 miles.
For all other Satisfied pads �
400 to 500 miles of moderate driving is recommended. Consumer should avoid heavy braking during this period. _________________ Lexus accessories
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