Accurate Acura brake disc service

American Honda requires refinishing of front brake discs only when they are scored or out of specification for runout or parallelism. Honda requires refinishing of front brake discs with an on-car lathe that mounts to the steering knuckle. Use of an on-car lathe is critical because it corrects runout of the hub and disc as an assembly. Two on-car brake lathes are recommended by Honda: the Kwik-Lathe, Model KWY-108000501 and the Accu-turn On-Car Brake Lathe, Model ACCHONOCLPKG.

A power driver is required for the rear-wheel-drive NSX and is highly recommended for all others. The model number for the Kwik-Lathe power driver is KWY-108012005. The Accu-turn lathe includes a power driver. The use of a power driver offers the following advantages:

* The disc is rotated at the optimum speed for a smooth and consistent cut.

* There is no need to climb in and out of the vehicle to start and stop the engine or shift the transmission.

* Securing the opposite wheel with a tie-down strap is not required.

* There is no waiting period for the engine to return to idle, and there is no concern about engine speed changes that can adversely affect brake disc cut and finish.

* The traction control system (TCS) or vehicle stability assist (VSA) are not involved.

* Consistent cutting speed increases cutting tool life.


Place the transmission in neutral. If you are not using a power drive system, start the engine and allow it to warm to operating temperature so that the idle speed will stabilize to its lowest RPM.

NOTE: MDX, RDX and all 4WD vehicles must have all four wheels off the ground (no contact at all four tires).

Raise the vehicle on a lift (frame type lift, not ramp type).

Check for loose wheel bearings and correct if needed.

Remove the front wheels, then reinstall the wheel nuts with flat washers/spacers and torque the wheel nuts to the specified wheel nut torque value (this simulates wheel installation, applying clamping value to the hub/disc).

Remove the front brake caliper assembly and support to prevent hose damage. If you are not using a power drive system and the vehicle is equipped with TCS or VSA, be sure to install a brake pad spreader between the pads on the hanging caliper. Also be sure to turn off the system (TCS or VSA). If the system is not turned off, the brakes may activate.

Install the vibration damper to the brake disc. If you are not using a power drive system, also install a protective band around the wheel nuts. Also, if you are not using a power drive system, use a fabric tie-down strap to secure the opposite brake disc (however, if you are working on an Integra Type-R, do not use a tie-down strap -- allow both front hubs to rotate freely).

Remove the tool bed from the brake lathe and mount the brake lathe to the steering knuckle with an Acura one-piece speed mount.  These speed mounts are available as follows:

P/N KWY-108006000 (for most models); P/N KWY-108007500 (MDX with two-piston calipers); P/N KWY-108009000 (TL with Brembo brakes); P/N KWY-108009500 (2005-07 RL).

Torque the lathe kit to adapter mounting bolts to a value of 24 ft.-lbs. using a torque wrench (do not use an impact wrench!). Torque the caliper bolts to a value of 40 ft.-lbs.

Adjust the power drive system so that the motor assembly is level with the brake disc and the centerline of the motor driveshaft is level and centered to the wheel hub spindle nut. Set the lower toggle switch on the drive motor to FWD (counterclockwise rotation) or REV (clockwise rotation). Install the cutting bits to the tool holders (on the Kwik-Way system, the cutting bit must face upward). Each cutting bit features three cutting tips. Inspect the tips for wear or damage. Rotate the bit to allow use of a fresh tip.

Reinstall the tool bed to the lathe with the top of the cuttings bits facing upward and the feed knobs facing down. Adjust the tool bed until the brake disc is centered between the two cutting bits. For proper refinishing, the brake disc must turn toward the top of the cutting bits. For example, if the lathe is mounted at the front of the left side disc, the disc must turn counterclockwise (normal driving direction). 

Do not set the cutting depth on the lathe to more than 0.008 in. (this is two divisions on the cutting knob). Make sure that you start your cut at least 0.12 in. beyond the worn area on the brake disc. NOTE: If you are cutting a larger diameter brake disc, such as that used on MDX and 1996-90 Legend, make sure to use the 15-degree cutting bit holders.


To obtain the smoothest cut and optimum finish, always use the slowest feed speed on the tool bed feed motor. Place the drive belt on the smallest pulley of the feed motor and on the largest pulley on the hand wheel. Plug in the tool bed feed motor and turn on the drive motor (toggle switch).

If you are not using a power driver, make sure that the transmission is in first gear or Reverse (second gear on Integra Type-Rs) and the engine is idling (not a fast idle). If the transmission and engine are at higher gears/speeds, you will damage the cutting bits.

Turn on the tool bed feed motor and snap it into place (there should be tension on the feed belt). Cut the brake disc until the cutting bits clear the outer edge of the disc. The cutting bits should produce a smooth, consistent finish with no chatter marks or grooves. If the disc did not clean-up on the first pass, reset the lathe and make a second pass.

Remove the vibration damper and protective band. Use a micrometer to measure disc thickness. Make sure that the thickness is within the service manual specifications. Clean the disc with hot soapy water and wipe dry. Use a vacuum cleaner to remove any dust or chips, but do not use compressed air. Remove the brake lathe system and cut the opposite disc in the same manner.  Reassemble according the service manual specifications.

Tags: Acura  Brakes 
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