air bleeding MAZDA MX-5 1994 User Guide

Before beginning any service procedure. refer to section T of this manual for air bag system service warnings and audio antitheft system alarm conditions . BRAKING SYSTEM INDEX ....................................... P- 2 OUTLINE ..................................... P- 4 SPEClFlCATlONS ........................... P- 4 BRAKE SYSTEM ............................. P- 5 PREPARATION ............................. P- 5 TROUBLESHOOTING GUIDE ................ P- 6 AIR BLEEDING ............................. P- 7 BRAKE HYDRAULIC LINE ................... P- 7 BRAKE FLUID .............................. P- 8 ............................. BRAKE PEDAL P- 9 MASTER CYLINDER (STANDARD) ............ P-11 MASTER CYLINDER (ABS) .................. P-14 POWER BRAKE UNIT ....................... P-20 PROPORTIONING BYPASS VALVE ........... P-23 FRONT BRAKE (DISC) ...................... P-25 CALIPER ................................... P-28 REAR BRAKE (DISC) ........................ P-29 CALIPER ................................... P-32 PARKING BRAKE SYSTEM .................... P-34 TROUBLESHOOTING GUIDE ................ P-34 PARKING BRAKE LEVER .................... P-34 PARKING BRAKE CABLE .................... P-36 ANTILOCK BRAKE SYSTEM (ABS) ............ P-37 DESCRIPTION .............................. P-37 PREPARATION ............................. P-37 TROUBLESHOOTING GUIDE ................ P-38 CIRCUIT DIAGRAM ......................... P-52 HYDRAULIC UNIT ........................... P-53 ........................ ABS CONTROL UNIT P-55 RELAYS .................................... P-56 ABS WHEEL SPEED SENSOR (FRONT) ....... P-58 ABS SENSOR ROTOR (FRONT) .............. P-59 ABS WHEEL SPEED SENSOR (REAR) ........ P-60 ABS SENSOR ROTOR (REAR) ............... P-61 25UOPX-001 Gartner Banana

BRAKE SYSTEM P MIRROR AIR BLEEDING The brakes should be bleed whenever a brake line is dis- connected. If a hydraulic line is disconnected at the mas- ter cylinder, start at the slave cylinder farthest from the brake master cylinder, and move to the next closest slave cylinder until all four cylinders have been bled. If the disconnection point is anywhere except the master cylinder, start at the point closest to the disconnection, and move to the next farthest slave cylinder until all four cylinders have been bled. 1. On level ground jack up the vehicle and support it evenly on safety stands. 2. Remove the bleeder cap and attach a vinyl tube to the bleeder screw. 3. Place the other end of the vinyl tube in a clear container. 4. One person should depress the brake pedal a few times, and then hold it in the depressed position. 5. A second person should loosen the bleeder screw, drain out the fluid, and close the screw by using the SST. 6. Repeat steps 4 and 5 until only clean fluid is seen. The reservoir should be kept about 3/4 full during bleeding to prevent air from reentering the lines. 7. Modify the brake pipe tightening torque to allow for a torque wrench-SST combination. (Refer to section GI) "Torque Formulas". 8. Tighten the brake pipe by using SST. 9. Check for correct brake operation. 10. Verify that there is no fluid leakage. Clean away any spilled fluid with rags. 11. After bleeding the air, add brake fluid to the reservoir up to the specified level. BRAKE HYDRAULIC LINE On-vehicle Inspection Check the following and replace parts as necessary. 1. Cracks, damage, and corrosion of the brake hose 2. Damage to the brake hose threads 3. Scars, cracks, and swelling of the flexible hose 4. All lines for fluid leakage Gartner Banana

P BRAKE SYSTEM Removal / Installation 1. When disconnecting the flexible hose and brake line, remove the clip after loosening the flare nut by using the SST. > 2. When connecting the flexible hose, do not over tighten or twist it. 3. Verify that the hose does not contact other parts when the vehicle bounces or when the steering wheel is turned all the way to the left or right. 4. Modify the brake pipe tightening torque to allow for a torque wrench-SST combination. (Refer to section GI) "Torque Formulas". 5. Tighten the flare nut by using the SST. Tightening torque: 13-22 N.m (1 3-2.2 kgf-m, %&-I 6 ft-lbf} 6. Bleed the air from the brake system. BRAKE FLUID Inspection Check the fluid level in the reservoir. It should be between MAX and MIN. If the fluid level is extremely low, check the brake system for leaks. J Fluid specification: FMVSS 11 6: DOT-3 Replacement 1. Follow the procedure outlined in Air Bleeding. (Refer to page P-7.) 2. Continuity air bleeding and replacing the brake fluid until only clean fluid is seen. 3. Fill the reservoir to MAX. Gartner Banana

P BRAKE SYSTEM k FIRST PEDAL VACUUM GAUG DEPRESSION FORCE GAUGE POWER BRAKE UNIT Quick Inspection, On-vehicle Power brake unit function check (Simple method) ii Step 1 1. With the engine stopped, depress the pedal a few times. 2. With the pedal depressed, start the engine. 3. If immediately after the engine starts the pedal moves down slightly, the unit is operating. Step 2 1. Start the engine and let it run 1 or 2 minutes. 2. Stop the engine. 3. Depress the pedal with the usual force. 4. If the first pedal stroke is long and becomes shorter with subsequent strokes, the unit is operating. 5. If a problem is found, inspect for damage or improper connection of the check valve or vacuum hose. Repair if necessary, and inspect it once again. Step 3 1. Start the engine. 2. Depress the pedal with the usual force. 3. Stop the engine with the pedal depressed. 4. Hold the pedal down for about 30 seconds. 5. If the pedal height does not change, the unit is operating. ,, 6. If there is a problem, check for damage or improper con- nection of the check valve or vacuum hose. Repair if necessary, and check once again. If the nature of the problem is still not clear after following the 3 steps above, follow the more detailed check described in "Method using tester," below. (Method using tester) Connect the SST, vacuum gauge, and pedal depression force gauge as shown in the figure. After bleeding the air from the SST, conduct the test as described in the 3 steps below. Inspection using gauges Connect the SST gauges, a vacuum gauge (A), and a pedal depression gauge (B) as shown. Bleed the air from the SST gauges before performing the following tests. a) Checking for vacuum loss Unloaded condition 1. Start the engine. 2. Stop the engine when the vacuum gauge indicates 66.7 kPa (500 mmHg, 19.7 inHg). 3. Observe the vacuum gauge for 15 seconds. If the gauge indicates 63.4-66.6 kPa (475-500 mmHg, ,, 18.7-19.7 inHg), the unit is operating. Gartner Banana