brake rotor MAZDA MIATA 1991 Factory Service Manual

ANTI-LOCK BRAKE SYSTEM
1988-91 BRAKES Mazda Anti-Lock Brake System
DESCRIPTION
The Anti-Lock Brake System (ABS) control unit senses reductions in front and rear wheel speed, and modulates
hydraulic pressure to the brakes to prevent wheel lock-up. The ABS consists of a hydraulic unit, 4 wheel speed
sensors and sensor rotors, valve relay, motor relay, pump motor, and ABS control unit. An ANTI-LOCK
warning light is located on the instrument panel. See Fig. 1
thru Fig. 3 .
Fig. 1: Locating Motor Relay & Valve Relay

Courtesy of MAZDA MOTORS CORP.

1991 Mazda MX-5 Miata
ANTI-LOCK BRAKE SYSTEM 1988-91 BRAKES Mazda Anti-Lock Brake System

1991 Mazda MX-5 Miata
ANTI-LOCK BRAKE SYSTEM 1988-91 BRAKES Mazda Anti-Lock Brake System
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WHEEL SPEED SENSOR ROTORS
Inspection
Perform a comprehensive visual inspection of sensor rotor. If any damage is noted, replace sensor rotor. Sensor
rotors are attached to wheel hubs.
REMOVAL & INSTALLATION
HYDRAULIC UNIT
Removal
Remove hydraulic lines from unit. Disconnect hydraulic unit connectors. Remove nuts securing unit. Remove
hydraulic unit.
Bleeding Hydraulic Unit
Before bleeding hydraulic unit, bleed brake system in appropriate sequence. See BRAKE LINE BLEEDING
SEQUENCE TABLE under BLEEDING BRAKE SYSTEM. Bleed hydraulic unit by opening bleeder screw on
unit. See Fig. 12
.
Installation
To install, reverse removal procedure. Tighten mounting bolts to specification. See TORQUE
ApplicationConnector Terminals (1)
Miata
Left Front"K" & "G"
Left Rear"O" & "Q"
Right Front"U" & "F"
Right Rear"L" & "P"
RX7
Left Front"D" & "F"
Left Rear"H" & "I"
Right Front"U" & "W"
Right Rear"X" & "Z"
929
Left Front"K" & "G"
Left Rear"O" & "Q"
Right Front"J" & "F"
Right Rear"L" & "P"
(1)See Fig. 4 or Fig. 5 to identify ABS control unit terminals.

1991 Mazda MX-5 Miata
ANTI-LOCK BRAKE SYSTEM 1988-91 BRAKES Mazda Anti-Lock Brake System
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SPECIFICATIONS TABLE at end of article.
Fig. 12: Locating Hydraulic Unit Bleeder Screw

Courtesy of MAZDA MOTORS CORP.
WHEEL SPEED SENSOR ROTOR
Removal (Miata)
Remove brake caliper. Remove wheel hub. On rear axle, carefully remove sensor rotor from axle using a chisel.
On front rotor, remove sensor rotor using Puller (49- 0839-425C).
Installation
Press sensor rotor onto axle using Installer (49- H026-101A). Install sensor rotor on front rotor with chamfered
edge toward hub using Press Adapter (49-F001-95). To complete installation, reverse removal procedure.
Tighten mounting bolts to specification. See TORQUE SPECIFICATIONS TABLE at end of article.
Removal & Installation (RX7)
Remove brake caliper and wheel hub. On rear hub, remove wheel hub from outer toe control hub using Puller
(49-F026-103) and Installer (49-F026-102). On front rotor, remove rotor-to-hub bolts using Allen wrench. On
rear rotor, remove rotor-to-hub screws. To install, reverse removal procedure. Tighten mounting bolts to
specification. See TORQUE SPECIFICATIONS TABLE at end of article.
Removal & Installation (929)

1991 Mazda MX-5 Miata
ANTI-LOCK BRAKE SYSTEM 1988-91 BRAKES Mazda Anti-Lock Brake System
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Remove brake caliper and wheel hub. On rear axle, carefully remove sensor rotor from axle using chisel. On
front rotor, remove sensor rotor using Puller (49-0839-425C). To install, press sensor rotors onto axle and front
rotor using Installer (49-H026-101A). On front rotor, install sensor rotor with chamfered edge toward hub. To
complete installation, reverse removal procedure. Tighten mounting bolts to specification. See TORQUE
SPECIFICATIONS TABLE at end of article.
WHEEL SPEED SENSOR
Removal & Installation
Unplug wheel sensor connector. Remove sensor bolt. Remove wheel sensor from vehicle. To install, reverse
removal procedure. On RX7, adjust wheel sensor so clearance between sensor and rotor is .016-.039" (.40-1.0
mm). Tighten mounting bolts to specification. See TORQUE SPECIFICATIONS TABLE at end of article.
DIAGNOSING ABS SYSTEM
ABS TESTER OPERATION
Fig. 13: Operating ABS Tester

Courtesy of MAZDA MOTORS CORP.
TESTING SEQUENCE

1991 Mazda MX-5 Miata
ANTI-LOCK BRAKE SYSTEM 1988-91 BRAKES Mazda Anti-Lock Brake System
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2. Release parking brake lever. Using a screwdriver, reach through parking brake handle hole in console and
rotate adjusting screw until stroke is 6-8 notches. Ensure rear wheels rotate freely. Ensure parking brake
warning light illuminates when brake lever is pulled one notch.
Miata, MX-6, MPV, Protege, RX7, 323, 626
1. On models with rear disc brakes, depress brake pedal several times. On models with rear drum brakes,
start engine and depress brake pedal several times while vehicle is moving in Reverse. Stop engine.
2. On all models, pull parking brake lever with a force of 22 lbs. (10 kg). If stroke is 5-7 notches, parking
brake is properly adjusted. If stroke is not 5-7 notches, raise and support rear of vehicle. Release parking
brake lever.
3. Rotate cable adjusting nut at lever end of cable (under console cover) until stroke is within specification.
On models equipped with rear disc brakes, ensure clearance between stopper and lever (at each caliper) is
not less than .08" (2 mm) on RX7, or zero on all other models. On all models, ensure parking brake
warning light illuminates when brake lever is pulled one notch.
PARKING BRAKE SHOES
929
Raise and support vehicle. Remove rear wheels. Remove service plug from rotor. Using a screwdriver, rotate
star wheel adjuster toward axle until rotor locks. Rotate adjuster in opposite direction 3-5 notches. Ensure rotors
turn freely and parking brake functions properly. Install service plug and rear wheels.
PEDAL FREE PLAY
Depress pedal a few times to eliminate vacuum. Pedal free play should be .16-.28" (4-7 mm). Adjust play by
loosening push rod lock nut. Turn push rod until correct free play is obtained. Tighten push rod lock nut.
PEDAL HEIGHT & STOPLIGHT SWITCH
1. Released pedal height is measured from carpet surface on vertical portion of firewall to pedal pad center.
Disconnect stoplight switch electrical connector. Loosen lock nut on stoplight switch. Move switch away
from pedal. Loosen push rod lock nut. Turn rod until correct pedal height is obtained. See BRAKE
PEDAL HEIGHT SPECIFICATIONS .
2. Adjust pedal free play. See PEDAL FREE PLAY
under ADJUSTMENTS. Tighten push rod lock nut.
Rotate stoplight switch until it contacts pedal and then rotate an additional 1/2 turn. Tighten stoplight
switch lock nut. Reconnect stoplight switch electrical connector.
3. Applied pedal height is measured from angled portion of firewall (without carpet) to pedal pad center.
Start engine. On B2200, B2600i and MPV, depress brake pedal with 33 lbs. (15 kg) pressure. On all other
models, depress brake pedal with 132 lbs. (60 k
g) pressure. tension should be checked and adjusted.
NOTE: Pedal height and stoplight switch information is not available for Navajo.

1991 Mazda MX-5 Miata
BRAKE SYSTEM 1991 BRAKES Mazda Brake System
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touch spindle face.
4. Insert screwdriver into slot provided behind pin tabs on inboard side of pin. Using pliers, compress end of
pin while using screwdriver to pry until tabs slip into spindle groove.
5. Place a 7/16" diameter punch on end of pin, and drive caliper pin out of caliper slide groove. Repeat
procedure for lower pin. Remove caliper from rotor. Remove outer brake pad. Compress anti-rattle spring
clip, and remove inner brake pad. Support caliper aside. Replace pad if lining thickness is less than
specified. See MINIMUM PAD LINING SPECIFICATIONS (FRONT) TABLE.
Installation
Use "C" clamp to push caliper piston into piston bore until it bottoms out. To install, reverse removal procedure.
Bleed air from brake system.
Removal & Installation (RX7 With 4-Piston Caliper)
Raise and support front of vehicle. Remove wheels. Remove pad pins and pad springs. See Fig. 6 . Remove
brake pads and shims. Replace pad if lining thickness is less than specified. See MINIMUM PAD LINING
SPECIFICATIONS (FRONT) . To install, reverse removal procedure. CAUTION: During installation, DO NOT tap caliper pin too far into spindle groove. If
this happens, tap pin in other direction until tabs snap back into place.
Tabs on each end of caliper pin must be free to catch on spindle flanks.

1991 Mazda MX-5 Miata
BRAKE SYSTEM 1991 BRAKES Mazda Brake System
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Fig. 12: View of Front Disc Brake Assembly 929
FRONT DISC BRAKE CALIPER
Removal & Installation
Raise and support front of vehicle. Remove wheel and disconnect brake hose. Plug all openings. Remove brake
disc pads. Remove remaining bolt(s). Remove caliper body from vehicle. To install, reverse removal procedure.
Bleed hydraulic system.
FRONT BRAKE ROTOR
NOTE: For removal and installation of front disc brake caliper for Navajo, see FRONT
DISC BRAKE PADS under REMOVAL & INSTALLATION.

1991 Mazda MX-5 Miata
BRAKE SYSTEM 1991 BRAKES Mazda Brake System
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Removal & Installation (B2200 & B2600i 2WD)
1. With caliper assembly removed, remove wheel hub grease cap, cotter pin, lock plate and ring adjusting
lock nut. Remove thrust washer and outer bearing from hub. Slide hub and rotor assembly from spindle.
2. Mark rotor-to-hub position. Separate rotor from hub. Machine rotor if lateral runout exceeds
specification. Replace rotor if measured thickness is less than specified minimum thickness. See DISC
BRAKE SPECIFICATIONS at end of article.
3. To install, reverse removal procedure and evenly tighten rotor-to-hub bolts. Adjust wheel bearings.
Removal & Installation (B2600i 4WD) 1) Remove front caliper. Set hub to FREE position. Remove hub
bolts. Remove hub as an assembly. Install 2 bolts and nuts to retain hub assembly together. Remove snap
ring and spacer.
4. Remove set bolt and plate. Remove nut. Remove rotor and hub assembly. Mark rotor-to-hub position.
Remove rotor from hub. Machine rotor if lateral runout exceeds specification. Replace rotor if measured
thickness is less than specified minimum thickness. See DISC BRAKE SPECIFICATIONS
at end of
article. To install, reverse removal procedure.
Removal & Installation (Miata, MPV, MX-6, Protege, RX7, 323 & 626)
1. Raise and support front of vehicle. Remove wheel. Remove caliper with brake hose connected. Support
caliper using rope. Remove 2 rotor-to-hub screws. Remove rotor.
2. Machine rotor if lateral runout exceeds specification. Replace rotor if measured thickness is less than
specified minimum thickness. See DISC BRAKE SPECIFICATIONS
at end of article. To install,
reverse removal procedure.
Removal & Installation (Navajo 2WD)
1. Raise vehicle, and support using safety stands. Remove wheel and caliper assemblies. Remove dust cap,
cotter pin, nut, washer and outer bearing. Carefully remove hub and rotor assembly. Remove inner
bearing and seal.
2. To install, reverse removal procedure. Adjust front wheel bearings. While rotating rotor, tighten adjusting
nut to 17-25 ft. lbs. (23-34 N.m). Back off adjusting nut 120-180 degrees. Install bearing retainer and new
cotter pin.
Removal (Navajo 4WD With Automatic Locking Hubs)
1. Raise vehicle, and support using safety stands. Remove wheel assembly and caliper. See FRONT DISC
BRAKE PADS under REMOVAL & INSTALLATION. Remove retainer washers from lug nut studs.
Remove automatic locking hub housing from spindle.
2. Remove snap ring from end of spindle shaft. Remove axle spacer. See Fig. 13
. Carefully pull plastic
moving cam off wheel bearing adjusting nut. Remove 2 plastic thrust spacers from adjusting nut. Using a
magnet, remove locking key.
CAUTION: DO NOT pry on plastic cam or spacers during removal as damage
may result. To prevent damaging spindle threads, remove locking
key before removing adjusting nut.

1991 Mazda MX-5 Miata
BRAKE SYSTEM 1991 BRAKES Mazda Brake System
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Fig. 13: Removing Front Rotor (Navajo with Automatic Locking Hubs)
Courtesy of FORD MOTOR CO.
3. If necessar
y, rotate adjusting nut slightly to relieve pressure on locking key. Using Hex Lock Nut Wrench

1991 Mazda MX-5 Miata
BRAKE SYSTEM 1991 BRAKES Mazda Brake System
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(T70T-4252-B), remove wheel bearing adjusting nut. Remove outer wheel bearing, and then remove
rotor.
Installation
When installing rotor, outer bearing and adjusting nut, tighten adjusting nut to 35 ft. lbs (47 N.m) to seat
bearings. Spin rotor, and back off adjusting nut 1/4 turn. Tighten adjusting nut to 16 INCH lbs. (1.8 N.m). To
install remaining components, reverse removal procedure. See Fig. 13
. After assembly is complete, wheel to
spindle end play should be .001-.003" (.02-.08 mm).
Removal (Navajo 4WD With Manual Locking Hubs)
1. Raise and support vehicle. Remove wheel assembly and caliper. See FRONT DISC BRAKE PADS
under REMOVAL & INSTALLATION. Remove retainer washers from lug nut studs. Remove manual
locking hub housing from spindle.
2. Remove snap ring from end of spindle shaft. Remove axle spacer. See Fig. 14
. Using Lock Nut Wrench
(T86T-1197-A), remove outer wheel bearing lock-nut. Remove lock washer. Using Lock Nut Wrench
(T86T-1197-A), remove inner wheel bearing lock nut, outer wheel bearing and rotor. CAUTION: Extreme caution must be used when aligning adjusting nut lug with
spindle locking key slot to prevent damage to locking key. Extreme
caution must be used when aligning fixed cam key with spindle key slot to
prevent damage to fixed cam.

1991 Mazda MX-5 Miata
BRAKE SYSTEM 1991 BRAKES Mazda Brake System
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