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Mazda RX7. Manual - part 84

BRAKE CALIPER BOLT CORROSION - CLEAN & SEAL MT 0995-11

Article Text

1983 Mazda RX7

For www.iluvmyrx7.com

Monday, September 03, 2001 03:36PM

ARTICLE BEGINNING

TECHNICAL SERVICE BULLETIN

BRAKE CALIPER BOLTS

Model(s): All Mazda Models
Category: Mazda Tips
Bulletin No.: MT 0995-11
Date: 1995

DESCRIPTION

When reinstalling disk brake calipers, use the following procedure
to secure the caliper bolts and seal against road corrosion. When
installing caliper mounting bolts, first clean the bolt threads of
any old residue. Be sure to clean out the female portion as well,
using a wire brush, brake cleaner and an air hose. When parts are dry
apply 3-4 drops of Loctite Threadlocking Adhesive/Sealant 272 (Loctite
part number 27200) on the male threads, one full thread back from the
lead thread. Assemble and torque to specification in less than 5-8
minutes.

END OF ARTICLE

BRAKE JUDDER REPAIR (CANADIAN) CAT. P, NO. 94-06

Article Text

1983 Mazda RX7

For www.iluvmyrx7.com

Monday, September 03, 2001 03:36PM

ARTICLE BEGINNING

TECHNICAL SERVICE BULLETIN

BRAKE JUDDER REPAIR

Model(s): 1983-95 Mazda Vehicles (Canadian)
Category: P - Brakes
Bulletin No.: 95-02
Date: May, 1995

NOTE: This bulletin supersedes Service Bulletin Cat. P, No. 94-06.

DESCRIPTION

Customers who complain of vibration or pulsation in the steering
wheel, brake pedal, floor or seat while applying the brakes may be
experiencing symptoms of brake judder. Judder is caused by:

  * Disk Thickness Variation (DTV)
  * rotor run-out and/or
  * rotor surface rust (which leads to DTV)

This bulletin describes the causes and corrections for each
condition.

CAUSES OF JUDDER

1. Disc Thickness Variation (DTV) - DTV creates a vibration/pulsation
during application of the brakes. DTV will increase with distance
travelled if the run-out of the disc is excessive.

2. Disc Rotor Run-Out - Run-out, or rotor "wobble", leads to DTV. It
is corrected by precision machining to bring the run-out within
specification.

3. Rotor Surface Rust - Under certain conditions (storage or use in
extreme environments), the surface of the brake rotors may become
rusted in the pad non-contact area. If this corrosion penetrates
the rotor surface deeply enough, it will not wear or rub off
during normal use. This will cause DTV.

CORRECTION

In order to effectively correct brake judder, rotor surfaces must be
precisely machined. Mazda Canada Inc., has evaluated both on and off-
car brake lathes and has determined that on-car lathes are more
precise and greatly reduces comeback repairs.

The steps necessary for correction of brake judder are as follows:

BRAKE JUDDER REPAIR (CANADIAN) CAT. P, NO. 94-06

Article Text (p. 2)

1983 Mazda RX7

For www.iluvmyrx7.com

Monday, September 03, 2001 03:36PM

1. If the vehicle is in dealer inventory and the condition is rotor
rust:

A. Clean the rotor surface by driving the vehicle several miles
while frequently applying the brakes.

B. If vibration/pulsation is still felt, processed to step "C".

C. Machine the rotor surface enough to remove all rust or surface
staining (generally 0.1 mm per side).

NOTE: If machining is performed, the Service Manager's signature must
appear on the repair order.

2. If the vehicle has been in service:

A. Verify customer's complaint with a test drive.

B. If brake judder is felt, proceed to step "C". If brake judder is
not felt, refer to the work shop manual or the NVH manual for
additional troubleshooting information.

C. Mark the front wheel(s) and the lug nut stud with chalk. This
will determine the original position of the wheel to the
rotor. Remove the front wheel(s).

NOTE: A high majority of brake judder is due to DTV of the front
rotors. Customer complaints of brake judder are most often
corrected by machining the front rotors only.

D. Measure the remaining front rotor thickness and run-out.
Determine if sufficient rotor material remains to allow
machining.
Limit: Stated minimum thickness for the model plus 0.8 mm.

E. If machining can be achieved, an on-car brake lathe is
recommended to ensure a precise rotor surface.

NOTE: After machining rotor(s) with an on-car brake lathe, you must
remove all metal cuttings (particles) from the ABS "toothed
ring" (the reluctor) and the ABS sensor. Failure to remove
these particles will prevent proper function of the ABS system.

F. If machining can not be achieved due to rotor thickness
limitations, the dealer should replace the rotor. To ensure a
successful repair, run-out and/or DTV must be removed by
on-car machining, even on new rotor(s).

G. Install the wheel in the same location relative to the hub as
it was originally positioned.

BRAKE JUDDER REPAIR (CANADIAN) CAT. P, NO. 94-06

Article Text (p. 3)

1983 Mazda RX7

For www.iluvmyrx7.com

Monday, September 03, 2001 03:36PM

H. Torque wheel lug nuts to the specifications in the service
manual.

I. Test drive the vehicle to confirm repair.

J. If the brake judder is still felt, correct the rear rotor(s)
using steps "C" through "I".

SERVICE TOOLS

The Accu-Turn (model 8750) On-Car Brake Lathe is recommended by
Mazda. The brake lathe is available through Mazda Canada's Equipment
Program at 1-800-33-6687.

WARRANTY INFORMATION

(Applies To Vehicles Covered Under Normal Warranty.)

Warranty Type: O
Symptom Code: 83
Damage Code: 9B
Part Number Main Cause: **** 33 25 *
**** 26 25 * (Rear of Vehicle - Rear Wheel
Drive Only)

Operation Number: P0113AMX/0.7 hrs. (Front/One Side)
P0113BMX/1.2 hrs. (Front/Both Sides)
P0214AMX/0.7 hrs. (Rear/One Side)
P0214BMX/1.2 hrs. (Rear/Both Sides)

NOTE: 1. Unnecessary replacement of rotors will result in warranty
claim denial.

2. Brake pad replacement costs will not be warrantable for
brake judder repair.

3. The 1995 SRT Microfiche (for the MX-3, RX-7, 929, MPV,
Miata, etc.) shows labor times for on-car rotor machining
are 0.7 hrs. Max for one side, and 1.2 hrs. Max for both
sides.

4. If an Accu-Turn on-car lathe is used, apply the labor time
from the table above. If an off-car lathe is used, refer to
the labor times from the 1994 SRT. The next issue of the SRT
microfiche will be revised to show the new labor times.

5. Please refer to the attached sheet for all valid off-car
brake and on-car brake machining operation codes for all
models and model years.

END OF ARTICLE

Content .. 82 83 84 85 ..