Rotors - Caliper-Mount Lathe Machining Setup Procedure
Article No.98-5A-41
03/18/98
BRAKES - ON-VEHICLE CALIPER-MOUNT LATHE
MACHINING SETUP PROCEDURES
LIGHT TRUCK:
1994-95 BRONCO, E-150, F-150
This TSB Article includes service tips for caliper-mount lathes only (Rotunda/Ammco and Rotunda/Accu-Turn). Ford Customer Service Division (FCSD) is in the process or replacing these lathes with hub-mount lathes (Rotunda/Pro-Cut). Please disregard this TSB upon returning the caliper-mount lathes. This TSB has also been revised to delete the lateral runout check.
ISSUE:
On-vehicle caliper-mounted brake rotor machining accessories from Rotunda, for Bronco and E/F-15O Series, are now available for service use. These accessories, when used with the Rotunda On-Vehicle Brake Lathes, will assist in addressing brake roughness, shudder, and steering wheel nibble resulting from disc brake rotor thickness variation induced by rotor runout.
ACTION:
Refer to the following Setup Procedure when using the new design accessories for on-vehicle rotor machining.
SETUP PROCEDURE
NOTE:
READ THE ENTIRE ROTUNDA 168-0004 AND/OR 104-00130 ON-THE-CAR LATHE OPERATION MANUALS BEFORE INSTALLING, OPERATING OR SERVICING THE LATHE.
1. After removing the caliper, visually inspect the inboard and outboard sides of the rotor and measure rotor thickness in three (3) locations. These locations should be on the center of the rotor surface, 120 degrees apart, ensuring the rotor is not below the minimum thickness specification of 24.4 mm (0.961").
NOTE:
FOR ROTORS EXHIBITING DEEP GOUGES OR GROOVES BEYOND 24.4 mm (0.961"), THE MINIMUM ROTOR THICKNESS, REPLACEMENT OF THE ROTOR IS NECESSARY.
2. Check wheel bearing end play. For optimum lathe performance, wheel bearing end play should not exceed a maximum of O.076 mm (0.003"). Refer to the appropriate model/year Service Manual if adjustment is necessary.
3. Be sure all machining is done with sharp, high quality tool bits.
4. Use Steps 4a through 4e for Rotunda 168-0004 On-The-Car Lathe:
a. Clean the knuckle assembly so it is free of rust or debris before mounting the Rotunda Dedicated Adapter (168-00029). Mount the lathe adapter to the knuckle using the vehicle's caliper bolts. Torque the bolts to 30-36 N.m (22-27 lb-ft).
b. Install the silencer band on the rotor.
c. Install the lathe to the adapter by mounting the bottom bolt first, M10x75 mm provided. Move the lathe up and install the second bolt. Torque both bolts to 30-36 N.m (22-27 lb-ft).
d. Secure the lathe drive yoke-to-rotor stud using one (1) concave washer provided in the lathe kit and one (1) vehicle lug nut. Put the drive unit into position so that the shaft and coupler are aimed at the center of the axle. Refer to the lathe operating manual for further instructions.
e. Refer to Pages 16-17 of the lathe operating manual for lathe operation and begin machining.
NOTE:
THE MAXIMUM CUT DEPTH MUST NOT EXCEED 0.15 mm (0.006").
5. Use Steps Sa through 5e for Rotunda 104-00130 On-The-Car Lathe:
a. Clean caliper mounting locations on the knuckle so they are free from rust and debris before mounting lathe arms.
b. Measure caliper bolt center distance with centering tool provided. Set caliper lathe tabs to the measured distance. Refer to the lathe operating manual for further instructions.
c. Attach the Rotunda Lower Lathe Caliper Green Bolt (104-00137, provided in the Rotunda upgrade kit) to the knuckle. Rotate lathe up and install the upper lathe caliper green bolt. Tighten both bolts to 20 N.m (15 lb-ft) maximum.
CAUTION:
BOLTS TORQUED BEYOND 20 N.m (15 LB-FT) MAY CAUSE DAMAGE TO THE BOLT THREADS AND/OR LATHE MOUNTING HARDWARE.
d. Select and install the appropriate silencer band on the rotor.
e. Secure the lathe lug adapter4o-rotor studs using three (3) vehicle lug nuts. Connect the rotor driving unit per the lathe operating manual and begin machining. The maximum cut depth must not exceed 0.15 mm (0.006").
6. After machining is complete, check the rotor thickness with a micrometer in three (3) locations (every 120 degrees) to be sure the rotor is above 24.4 mm (0.961") minimum allowable thickness.
7. Remove lathe.
8. Inspect and clean any corrosion buildup under and around the knuckle rail clips and spring clips.
CAUTION:
BE SURE LUBRICANT DOES NOT GET ON THE ROTORS, LININGS, OR CALIPER PISTON BOOTS.
a. Lubricate between knuckle rail and spring clips with Silicone Brake Caliper Grease and Dielectric Compound (D7AZ-19A331-A).
b. Lightly apply Silicone Brake Caliper Grease and Dielectric Compound where spring clip contacts the brake pad. There are four (4) lubrication points for each brake pad:
^ Upper pad slide area
^ Upper anti-rotation ear
^ Lower pad slide area
^ Lower anti-rotation ear
9. Reassemble the vehicle.
10. Pump the brake pedal ten (10) times using strokes not greater than 76.2 mm (3") before moving the vehicle. Using medium braking force, a minimum of ten (10) stops must be made by the mechanic from 64 km/h (40 mph) to zero, this assures proper brake performance before releasing vehicle to the customer.
Advise the customer of the "Breaking Your Vehicle In" section in the front of their Owner Guide. This section recommends that the customer avoid sudden stops due to new brake linings. It suggests that the following steps be taken:
^ Watch traffic carefully so that you can anticipate when to stop
^ Begin braking well in advance
^ Apply the brakes gradually
The break-in period for new brake linings lasts for 160 km (100 miles) of city driving or 1,600 km (1,000 miles) of highway driving.
OTHER APPLICABLE ARTICLES: 94-25-2, 98-5A-13
SUPERSEDES: 95-23-8
WARRANTY STATUS: INFORMATION ONLY
OASIS CODES: 301000, 703000