Acura TSX / Honda Accord CL. Manual — part 259

Fig. 10: Brake System Inspection Chart
Courtesy of AMERICAN HONDA MOTOR CO., INC.

BRAKE HOSES & LINES

Inspect the brake hoses, for damage, deterioration, leaks, interference, and twisting. Check the brake lines for
damage, rusting, and leakage. Also check for bent brake lines. Check for leaks at hose and line joints or
connections, and retighten if necessary. Check the master cylinder and ABS modulator unit for damage and
leakage. See Fig. 11 .

NOTE:

Replace the brake hose clip whenever the brake hose is serviced.

2004 Acura TSX

2004 BRAKES Disc - TSX

Fig. 11: Identifying Brake Hoses & Lines Inspection Points
Courtesy of AMERICAN HONDA MOTOR CO., INC.

COMPONENT TESTING

BRAKE BOOSTER

Functional Test

1. With the engine stopped, press the brake pedal several times to deplete the vacuum reservoir, then press

the pedal hard, and hold it for 15 seconds. If the pedal sinks, either the master cylinder is bypassing
internally, or the brake system (master cylinder, lines, modulator, or calipers) is leaking.

2. Start the engine with the pedal pressed. If the pedal sinks slightly, the vacuum booster is operating

normally. If the pedal height does not vary, the booster or check valve is faulty.

3. With the engine running, press the brake pedal lightly, and shift transmission to "D" position. Apply just

enough pressure to hold back A/T creep. If the brake pedal sinks more than .4" (10 mm), in 3 minutes, the
master cylinder is faulty. A slight change in pedal height when the A/C compressor cycles on and off is
normal.

Leak Test

NOTE:

A/C compressor load changes the vacuum available to the booster.

2004 Acura TSX

2004 BRAKES Disc - TSX

1. Press the brake pedal with the engine running, then stop the engine. If the pedal height does not vary

while pressed for 30 seconds, the vacuum booster is okay. If the pedal rises, the booster is faulty.

2. Turn the engine off and wait 30 seconds. Press the brake pedal several times using normal pressure.

When the pedal is first pressed, it should be low. On consecutive applications, the pedal height should
gradually rise. If the pedal position does not vary, check the booster check valve. See BOOSTER
CHECK VALVE TEST .

Booster Check Valve Test

1. Disconnect the brake booster vacuum hose at the booster "A". See Fig. 12 . The check valve "B" is built

into the hose.

2. Start the engine, and let it idle. There should be vacuum available. If no vacuum is available, the check

valve is not working properly. Replace the brake booster vacuum hose and check valve, and retest.

3. Start the engine, and then pinch the brake booster vacuum hose between the check valve and the booster.

Turn the engine off, and wait 30 seconds. Press the brake pedal several times using normal pressure.
When the brake pedal is first pressed, it should be low. On consecutive applications, the brake pedal
height should gradually rise. If the pedal position does not vary, replace the brake booster. If the pedal
position varies, replace the brake booster vacuum hose/check valve assembly.

Fig. 12: Testing Booster Check Valve
Courtesy of AMERICAN HONDA MOTOR CO., INC.

2004 Acura TSX

2004 BRAKES Disc - TSX

BRAKE FLUID LEVEL SWITCH

1. Check for continuity between the terminals "A" with the float in the down position and the up position.

See Fig. 13 . Remove the brake fluid completely from the reservoir. With the float down, there should be
continuity. Fill the reservoir with brake fluid to MAX line "B". With the float up, there should be no
continuity.

Fig. 13: Identifying Brake Fluid Level Switch Terminals
Courtesy of AMERICAN HONDA MOTOR CO., INC.

PARKING BRAKE SWITCH

1. Remove center console. See CENTER CONSOLE under REMOVAL & INSTALLATION. Disconnect

the connector "A" from the switch "B". See Fig. 14 .

2. Check for continuity between the positive terminal "C" and body ground:

2004 Acura TSX

2004 BRAKES Disc - TSX