Brakes - Ammco On Car Brake Lathe Operating Guidelines

Classification:
BR92-004



Section:
Brake



Reference:
TECHNICAL BULLETIN NTB92-062



Models:
All models



Date:
August 18, 1992



AMMCO ON-CAR BRAKE LATHE OPERATING GUIDELINES

APPLIED MODEL:
All models

SERVICE INFORMATION

To ensure the best possible surface finish and least amount of run-out and rotor thickness variation when using the Ammco on-car brake lathe, the following guidelines should be observed.

SERVICE PROCEDURE


Before mounting the brake lathe on the vehicle ensure the following:





1. The V-way between the carriage and carriage jib must be clean and adjusted properly (see Operation Manual for adjustment procedure). Wipe off sliding surfaces with a soft cloth after each use.

2. The cutters and cutting bits must be tight in their mounts and positioned properly. Change cutting bits when they become dull.



3. When securing the adjustable mounting brackets to the caliper mount/knuckle the mounting surfaces must be smooth and free of burrs.

4. Make sure the adjustable mounting brackets are securely mounted to caliper mount/knuckle. There should be no movement between the cutting tool and the caliper mount/knuckle.


Rotor Driving Unit Before using the drive unit ensure the following:





1. Before using the rotor driving unit ensure that all lug nuts are installed on the lugs (including the lugs not used for the lug adaptor). All lug nuts should be evenly torqued, to at least 40 ft.lbs. Do not over-tighten the lug nuts as damage may occur to the lug adaptor legs.



2. To prevent chatter and ensure a smooth rotor finish, install the largest and heaviest silencer band possible around the outside diameter of the rotor.



Rotor Cutting

Before engaging the cutting tool, ensure the following:

1. Using the dial indicator, measure rotor/hub run-out prior to resurfacing rotor and adjust cutting depth to eliminate this run-out. Each cut may be between 0.05 mm and 0.25 mm (0.002" and 0.010"). Additional cuts may be necessary to eliminate all the run-out.






2. Using a micrometer, measure rotor thickness in at least 8 even locations around the rotor.
Do not cut below the minimum rotor thickness specification. Replace rotor if the run-out cannot be eliminated without exceeding the minimum rotor thickness specification.






3. After rotor resurfacing is completed, measure the rotor/hub run-out using a dial indicator.
Ensure that the run-out is below the specification for the vehicle. If runout is not within specifications, turn the rotors again. Properly machined rotors will have almost zero runout (.001" or less) with no measurable thickness variation.

4. Do not smooth the rotor surface with sand paper or other abrasive material.