1997 MAZDA MX-5 brake

Fig. 10: Identifying Instrument Cluster Connector Terminals
Courtesy of MAZDA MOTORS CORP.
STOPLIGHT SWITCH
Disconnect stoplight switch connector. Using ohmmeter, check continuity between stoplight switch terminals.
With brake pedal depressed, continuity should exist. With brake pedal released, continuity should not exist. If
continuity is not as specified, replace stoplight switch.
MOTOR RELAY
1. Turn ignition off. Disconnect ABS Control Module (ABS CM) connector. See COMPONENT
LOCATIONS . Connect Adapter Harness (49-F066-002) to ABS CM connector. Turn ignition on. Using
voltmeter, measure voltage between terminals "X" and AB of ABS CM connector. See Fig. 3
. Voltage
should be zero volts. Apply 12 volts to terminal "B" an d ground terminal "G" of ABS CM connector.
Using voltmeter, measure voltage between terminals "X" and AB of ABS CM connector. Voltage should
be 12 volts. If voltage is not as specified, check wiring harness. If wiring harness is okay, go to next step.
2. Remove motor relay from hydraulic unit. See Fig. 14
. Using ohmmeter, check continuity between
terminals "B" and "C" of motor relay. See Fig. 11
. Continuity should exist. Apply 12 volts to terminal
"C" and ground terminal "B". Using ohmmeter, check continuity between terminals "A" and "D" of motor
rela
y. Continuity should exist. If continuity is not as specified, replace motor relay.

1997 Mazda MX-5 Miata
ANTI-LOCK BRAKE SYSTEM 1997 BRAKES Mazda - Anti-Lock
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Fig. 11: Identifying Motor Relay Terminals
Courtesy of MAZDA MOTORS CORP.
VALVE RELAY
1. Turn ignition off. Disconnect ABS Control Module (ABS CM) connector. See COMPONENT
LOCATIONS . Connect Adapter Harness (49-F066-002) to ABS CM connector. Turn ignition on. Using
voltmeter, measure voltage between terminal AB and terminals "E", "Z", "Y", AG, BA and BB of ABS
CM connector. See Fig. 3
. Voltage on all terminals should be zero volts. If voltage is as specified, go to
next step. If voltage is not as specified, check wiring harness and repair as necessary. If wiring harness is
okay, go to step 3).
2. Apply 12 volts to terminal "B" and ground terminal AK of ABS CM connector. Using voltmeter, measure
voltage between terminal AB and terminals "E", "Z", "Y", AG, BA and BB of ABS CM connector. See
Fig. 3
. Voltage on all terminals should be 12 volts. If voltage is not as specified, check wiring harness. If
wiring harness is okay, go to next step.
3. Remove valve relay from hydraulic unit. See Fig. 14
. Using ohmmeter, check continuity between
terminals "B" and "C" of valve relay. See Fig. 12
. Continuity should exist. Apply 12 volts to terminal
"B" and ground terminal "C". Using ohmmeter, check continuity between terminals "A" and "D" of valve
rela
y. Continuity should exist. If continuity is not as specified, replace valve relay.

1997 Mazda MX-5 Miata
ANTI-LOCK BRAKE SYSTEM 1997 BRAKES Mazda - Anti-Lock
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Sunday, July 05, 2009 1:48:49 PMPage 18 © 2005 Mitchell Repair Information Company, LLC.

Fig. 12: Identifying Valve Relay Terminals
Courtesy of MAZDA MOTORS CORP.
WHEEL SPEED SENSORS
On-Vehicle Inspection
Remove wheel. Inspect wheel speed sensor for looseness and damage. Replace as necessary. Measure clearance
between wheel speed sensor and sensor rotor. See Fig. 13
. Clearance should be .012-.043" (.3-1.1 mm). If
clearance is not as specified, replace wheel speed sensor or sensor rotor.
Resistance Test
Disconnect wheel speed sensor connector. Using ohmmeter, measure resistance between wheel speed sensor
terminals. Resistance should be 800-1200 ohms. If resistance is not as specified, replace wheel speed sensor.
Voltage Test
Ensure vehicle is on level surface. Raise and support vehicle on safety stands. Disconnect wheel speed sensor
connector. Using voltmeter, while rotating wheel one revolution per second, measure voltage between wheel
speed sensor terminals. Voltage should be .25-1.2 volts (AC). If voltage is not as specified, replace wheel speed

1997 Mazda MX-5 Miata
ANTI-LOCK BRAKE SYSTEM 1997 BRAKES Mazda - Anti-Lock
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Sunday, July 05, 2009 1:48:49 PMPage 19 © 2005 Mitchell Repair Information Company, LLC.

sensor or sensor rotor.
Fig. 13: Measuring Wheel Speed Sensor Clearance

Courtesy of MAZDA MOTORS CORP.
WHEEL SPEED SENSOR ROTORS
Inspection
Perform a comprehensive visual inspection of wheel speed sensor rotor. If any teeth are damaged or missing, or
any other damage is noted, replace wheel speed sensor rotor.
REMOVAL & INSTALLATION
ABS CONTROL MODULE
Removal & Installation
1. Disconnect negative battery cable. Roll back carpet from passenger-side footwell. Remove ABS control
module protector panel (if equipped).

1997 Mazda MX-5 Miata
ANTI-LOCK BRAKE SYSTEM 1997 BRAKES Mazda - Anti-Lock
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2. Disconnect ABS control module electrical connector. Remove ABS control module mounting bolts/nuts.
Remove ABS control module. To install, reverse removal procedure. Tighten ABS control module
mounting bolts/nuts to 61-87 INCH lbs. (6.9-9.8 N.m).
HYDRAULIC UNIT
Removal & Installation
1. Disconnect negative battery cable. Disconnect hydraulic unit electrical connector. Using Flare Nut
Wrench (49-0259-770B), disconnect brakelines from hydraulic unit. Note location of brakelines for
installation reference. Disconnect electrical connectors. Remove hydraulic unit mounting bolts and nuts.
2. Remove hydraulic unit. To install, reverse removal procedure. Tighten mounting bolts and nuts to
specification. See TORQUE SPECIFICATIONS
. Add fluid and bleed air from system. See
BLEEDING BRAKE SYSTEM
.
FRONT WHEEL SPEED SENSOR ROTOR
Removal
Raise and support vehicle. Remove front wheel assemblies. Remove brake caliper and wire aside. Remove
rotor. Remove grease cap and wheel bearing lock nut. Remove wheel hub. Using Puller (49-0839-425C) and
Attachment (49-F027-007), remove wheel speed sensor rotor from hub.
Installation
To install, reverse removal procedure. Tighten bolts and nuts to specification. See TORQUE
SPECIFICATIONS .
REAR WHEEL SPEED SENSOR ROTOR
Removal
Raise and support vehicle. Remove rear wheel assemblies. Remove brake caliper and wire aside. Remove wheel
bearing lock nut. Remove lower control arm-to-rear steering knuckle bolt and nut. Remove drive axle. DO NOT
disassemble drive axle assembly to remove sensor rotor. Replace drive axle assembly.
Installation
To install, reverse removal procedure. Tighten bolts and nuts to specification. See TORQUE
SPECIFICATIONS .
WHEEL SPEED SENSOR
Removal & Installation
Raise and support vehicle. Remove wheel assemblies. Disconnect wheel speed sensor electrical connector.
Remove wheel speed sensor mounting bolt. Remove wheel speed sensor from vehicle. To install, reverse

1997 Mazda MX-5 Miata
ANTI-LOCK BRAKE SYSTEM 1997 BRAKES Mazda - Anti-Lock
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removal procedure. Tighten mounting bolt to specification. See TORQUE SPECIFICATIONS.
VALVE & MOTOR RELAYS
Removal & Installation
Disconnect negative battery cable. Remove relay cover from hydraulic unit. Remove valve and motor relays.
See Fig. 14
. To install, reverse removal procedure.
Fig. 14: Locating Valve Relay & Motor Relay

Courtesy of MAZDA MOTORS CORP.
ADJUSTMENTS
MASTER CYLINDER PUSH ROD
1. Before installing master cylinder, measure clearance between master cylinder piston and power brake unit
push rod. Turn adjusting nut on Adjustment Gauge (49-B043-001) clockwise to fully retract gauge rod.
Place adjustment gauge onto power brake unit and tighten mounting nuts to 88-138 INCH lbs. (9.9-15.6
N.m).
2. Using a hand-held vacuum pump, apply 19.7 in. Hg to power brake unit. Turn adjusting gauge nut
counterclockwise until
gauge rod just contacts push rod end of power brake unit. Perform STEP 1. See

1997 Mazda MX-5 Miata
ANTI-LOCK BRAKE SYSTEM 1997 BRAKES Mazda - Anti-Lock
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Fig. 15 .
3. Lightly push on end of adjusting gauge rod to ensure it is properly seated. Verify no gap exists between
adjusting nut and adjusting gauge body. Remove adjusting gauge from power brake unit without
disturbing adjusting nut. Place adjusting gauge on master cylinder.
4. Lightly push on end of adjusting gauge rod to ensure gauge rod is bottomed in master cylinder piston.
Ensure no clearance exists between adjusting gauge body and adjusting nut (clearance "B") or between
body and master cylinder (clearance "C"). Perform STEP 2. See Fig. 15
.
5. If clearance "B" exists, push rod is too short. If clearance "C" exists, push rod is too long. To adjust
clearance "B", go to next step. To adjust clearance "C", go to step 8).
6. To adjust clearance "B", lightly push on end of adjusting gauge rod. Using a feeler gauge, measure
clearance between adjusting nut and adjusting gauge. Perform STEP 3. See Fig. 15
.
7. Using Push Rod Adjuster (49-B043-004) and Adapter (49-B043-003), turn push rod nut to lengthen
power brake booster push rod an amount equal to amount measured at clearance "B" in step 6). Perform
STEP 4. See Fig. 15
.
8. To adjust clearance "C", measure and record adjusting gauge rod height D1. Perfrom STEP 5. See Fig.
15 . Turn adjusting nut until adjusting gauge body sits squarely on master cylinder.
9. Turn adjusting nut only enough for body to touch adjusting gauge. Measure and record adjusting gauge
height D2 of adjusting gauge rod. Perform STEP 6. See Fig. 15
. Subtract D1 from D2 measurement.
10. Using push rod adjuster and adapter, turn push rod nut to shorten power brake booster push rod an
amount equal to difference between hei
ght D1 and D2. Perform STEP 4. See Fig. 15 . NOTE: When lightly pushing on end of adjusting gauge rod in step 4), only use
enough pressure to bottom rod in piston. Too much pressure may cause a
false reading.
NOTE: Push rod threads are specially designed so bolt becomes harder to turn
past a certain point to prevent loosening of bolt. Turn bolt only within this
range.

1997 Mazda MX-5 Miata
ANTI-LOCK BRAKE SYSTEM 1997 BRAKES Mazda - Anti-Lock
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Fig. 15: Adjusting Master Cylinder Push Rod
Courtesy of MAZDA MOTORS CORP.
BRAKE 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. Rotate switch away
from pedal. Loosen push rod lock nut. Rotate push rod until correct pedal height is as specified. See
BRAKE PEDAL HEIGHT SPECIFICATIONS
table.
2. Adjust pedal free play. See BRAKE PEDAL FREE PLAY
under ADJUSTMENTS. Tighten push rod
lock nut. Tighten push rod lock nut to 18-25 ft. lbs. (24-34 N.m).
3. Rotate stoplight switch until it contacts pedal, then rotate an additional 1/2 turn. Tighten stoplight switch
lock nut to 10-13 ft. lbs. (14-18 N.m). Reconnect stoplight switch electrical connector.
4. Applied pedal height is measured from angled portion of firewall (without carpet) to pedal pad center.
Start engine. Depress brake pedal with a pressure of 132 lbs. (60 kg).
5. Measure applied pedal height. See BRAKE PEDAL HEIGHT SPECIFICATIONS
table. If distance is
not as specified, check for air in system or worn pads. Repair as necessary.
BRAKE PEDAL HEIGHT SPECIFICATIONS
BRAKE PEDAL FREE PLAY
ApplicationIn. (mm)
Pedal Released6.8-7.1 (171-181)
Pedal Applied (1) 3.7 (95)
(1)Minimum height.

1997 Mazda MX-5 Miata
ANTI-LOCK BRAKE SYSTEM 1997 BRAKES Mazda - Anti-Lock
Microsoft
Sunday, July 05, 2009 1:48:49 PMPage 24 © 2005 Mitchell Repair Information Company, LLC.