Mazda MX-5 Miata (1997+). Manual - part 11

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

  

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

  

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

  

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 height 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