Fulltext TSBs

Technical Service Bulletins

 
TSB
98-5A-32
  • BRAKES – ON-VEHICLE CALIPER-MOUNT LATHE MACHINING SETUP PROCEDURES
Publication Date: MARCH 18, 1998

LIGHT TRUCK:
1995-1996 E-250, E-350, F-250, F-350

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 of 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 E/F-250-350 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 And Rotor Turning Procedure when using the new design accessories for on-vehicle rotor machining.

SETUP AND ROTOR TURNING PROCEDURE

NOTE:READ THE ENTIRE ROTUNDA/ACCU-TURN AND ROTUNDA/AMMCO OPERATION MANUALS BEFORE INSTALLING, OPERATING OR SERVICING THE LATHE.

  1. Prior to removing the tire/wheel, check the wheel bearing for excessive play and/or roughness. Repair as necessary.
  2. Remove the tire/wheel and turn the steering wheel so that the caliper or caliper anchor can be removed depending on the type of lathe being used.
  3. Suspend the caliper or caliper anchor out of the way using a wire or plastic tie strap being careful not to damage any brake line.

    NOTE:ROTUNDA/AMMCO: THE ANCHOR IS NOT TO BE REMOVED.

    NOTE:ROTUNDA/ACCU-TURN: THE ANCHOR AND CALIPER ARE REMOVED.

  4. After removing the caliper, visually inspect the inboard and outboard sides of the rotor to assure that there are no deep gouges or nicks. Measure rotor thickness in three (3) locations. These locations should be on the center of the rotor surface, 120 degrees apart, ensuring that the rotor is not below the minimum thickness specification of 28mm (1.102″).

    NOTE:FOR ROTORS EXHIBITING DEEP GOUGES OR GROOVES BEYOND 28mm (1.102″), THE MINIMUM ROTOR THICKNESS, REPLACEMENT OF THE ROTOR IS NECESSARY.

  5. Check wheel bearing end play. For optimum lathe performance, wheel bearing end play should not exceed a maximum of 0.076mm (0.003″) as shown in Figure 1. Refer to the appropriate model/year Service Manual if adjustment is necessary.


    Figure 1 – Article 98-5A-32

  6. Be sure all machining is done with sharp, high quality tool bits.
  7. Use Steps 7-a through 7-e for Rotunda/Accu-Turn Lathe Machines:

    NOTE:REMOVE CALIPER AND ANCHOR.

    1. Clean the knuckle assembly free of rust or debris before mounting the Rotunda Dedicated Adapter (168-00030). Mount the lathe adapter to the knuckle (Figures 2 and 3) using the two (2) standard M16x50mm bolts provided. Torque the bolts to 54 N-m (40 lb-ft).


      Figure 2 – Article 98-5A-32




      Figure 3 – Article 98-5A-32

      NOTE:DO NOT USE THE BOLTS FROM THE VEHICLE THAT HOLDS THE ANCHOR TO THE KNUCKLE. THEY ARE SPECIAL BOLTS WITH AN INTERFERENCE THREAD FIT AND WILL DESTROY THE ADAPTER’S THREADS. USE THE TWO (2) STANDARD M16x50mm BOLTS PROVIDED.

    2. Install the silencer band onto the rotor.
    3. Install the lathe to the adapter by mounting the bottom bolt first, M10x25mm provided. Move the lathe up and install the second bolt. Torque both bolts to 54 N-m (40 lb-ft).
    4. Secure the lathe drive yoke-to-rotor stud using one (1) concave washer provided in the Lathe Kit (168-00033) and one (1) vehicle Lug Nut (F4UZ-1012-A). Refer to Figure 4. 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 (Pages 14 and 15) for further instructions.


      Figure 4 – Article 98-5A-32

      NOTE:FOR E/F-SERIES DUAL WHEEL VEHICLES, DO NOT USE THE VEHICLE’S LUG NUT. USE LUG NUT F4UZ-1012-A.

    5. Refer to Pages 16-17 of the lathe operating manual for lathe operation and begin machining.

      NOTE:THE MAXIMUM CUT DEPTH MUST NOT EXCEED 0.15mm (0.006″) PER SIDE.

  8. Use Steps 8-a through 8-e for Rotunda/Ammco Lathe Machines:

    NOTE:THE ANCHOR IS NOT TO BE REMOVED.

    1. Clean caliper mounting locations on the knuckle free from rust and debris before mounting lathe arms.
    2. Measure caliper bolt center distance with centering tool provided. Set caliper lathe tabs to the measured distance (Figure 5). Refer to the lathe operating manual for further instructions.


      Figure 5 – Article 98-5A-32

    3. Attach the Rotunda Lower Lathe Caliper Green Bolt (104-00137, provided in the Rotunda/Ammco upgrade kit) to the knuckle. Refer to Figure 6. Rotate lathe up and install the upper lathe caliper green bolt. Tighten both bolts to 20 N-m (15 lb-ft) maximum.


      Figure 6 – Article 98-5A-32

      CAUTION:BOLTS TORQUED BEYOND 20 N-m (15 LB-FT) MAY CAUSE DAMAGE TO THE BOLT THREADS AND/OR LATHE MOUNTING HARDWARE.

    4. Select and install the appropriate silencer band onto the rotor.
    5. Secure the lathe lug adapter-to-rotor studs using four (4) vehicle lug nuts. Connect the rotor driving unit per the lathe operating manual and begin machining. The maximum cut depth must not exceed 0.15mm (0.006″) per side.

      NOTE:FOR E/F-SERIES DUAL WHEEL VEHICLES, DO NOT USE THE VEHICLE’S LUG NUT. USE LUG NUT F4UZ-1012-A.

  9. 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 28mm (1.102″) minimum allowable thickness.
  10. Remove lathe and reassemble the vehicle.
  11. Pump the brake pedal five (5) times using strokes not greater than 76.2mm (3″) before moving the vehicle. Using medium braking force, a minimum of five (5) stops must be made by the technician from 64 km/h (40 mph) to zero. This assures proper brake performance before releasing vehicle to the customer.

    NOTE:THE FOLLOWING PARTS MUST BE USED WITH THE ACCU-TURN ON-VEHICLE LATHE TO PROPERLY SERVICE THE VEHICLE.


    ROTUNDA PART NUMBERS FOR ACCU-TURN LATHE
    Part NumberPart Name
    168-00030E/F-250-350 Adapter
    168-00033Concave Washer
    104-00137Bolts (Green Head)



PART NUMBERPART NAME
F4UZ-1012-ALug Nut

OTHER APPLICABLE ARTICLES:

94-25-2

SUPERSEDES:

96-7-18

WARRANTY STATUS:

Information Only

OASIS CODES:

301000, 302000, 703000


Copyright © 1998 Ford Motor Company