Nissan 240sx Brake System (s13)

1989-1994 Nissan 240sx S13

Nissan's 240SX brake system is operated hydraulically using a tandem master cylinder and vacuum power unit. All models have front and rear disc brakes.

BRAKE BLEEDING PROCEDURES

Check fluid level in master cylinder frequently during bleeding procedure. Bleed brake system in proper sequence.

• Nissan 240sx S13 1989-1994
  • Sequence: LR, RR, LF, RF

ADJUSTMENTS

POWER BRAKE UNIT OUTPUT ROD
1. Attach a hand-held vacuum pump to power brake unit supply port.

Apply 20 in. Hg vacuum to power brake unit. Measure length of output rod extending from power brake unit housing.
2. Adjust output rod length if necessary. If output rod length cannot be adjusted properly, replace power brake unit.

BRAKE PEDAL HEIGHT AND FREE PLAY
1. Measure pedal height from pressure face of pedal pad to floor pan insulator, without carpet.

• AT: 7.3-7.7 Inches (186-196 mm)
• MT: 7.0-7.4 Inches (177-187 mm)

2. To adjust pedal height, loosen brake booster input rod lock nut, and rotate input rod to attain proper height. Tighten lock nut, and adjust stoplight switch. Ensure pedal free play is .04-.12" (1.0-3.0 mm).

PARKING BRAKE
1. Remove parking brake lever cover. Raise and support rear of vehicle. Pull up on parking brake lever using force of 44 lbs. (20 kg). Rear wheels should lock at appropriate lever stroke.

• 240SX: 6-8 notches

2. Adjust parking brake using adjusting nut located beside or below parking brake lever. After releasing lever, ensure rear wheels rotate freely and slack is not present at rear cables.

STOPLIGHT SWITCH AND AUTOMATIC SPEED CONTROL DEVICE SWITCH
1. Both switches are located below dash panel, at brake pedal bracket. Adjust brake pedal height.

• AT: 7.3-7.7 Inches (186-196 mm)
• MT: 7.0-7.4 Inches (177-187 mm)

2. Check clearance and position of switches. Clearance between brake pedal stopper rubber and threaded end of switch should be.01-.04" (0.3-1.0 mm). To adjust, loosen lock nut and turn switch body. After adjustment, tighten lock nut.

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POWER BRAKE UNIT TESTING

Determine whether source of problem is in power brake unit or check valve. Always inspect check valve. DO NOT disassemble power brake unit. After air-tight and operational tests, replace complete assembly if problem is determined to be in power brake unit.

Air-Tight Check
1. Start engine, and operate it for 2 minutes. Turn engine off. Depress brake pedal several times. If brake pedal height rises gradually on successive pedal depressions, go to next step. If pedal does not rise on successive pumps, check for air leak.
2. Start engine. Depress brake pedal and turn engine off. Hold brake pedal down for 30 seconds. If brake pedal height does not change, power brake unit is air tight. If pedal height changes, check for air leak.

Operational Check
With engine off, depress brake pedal several times until pedal height no longer changes. Press and hold brake pedal down. Start engine. If pedal goes down slightly, power brake unit is okay. If pedal does not move, check for air leak.





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1989-1994 Nissan 240sx S13

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