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Brake System Bleeding Ford Bronco II I

Mechanical - Hydraulic ~545 words

DESCRIPTION

Brake system bleeding is necessary any time air has been introduced into brake system. Bleed brakes at all four wheels if master cylinder lines have been disconnected or master cylinder has run dry.

Bleeding may be done either by using pressure bleeding equipment or by manually pumping brake pedal and using bleeder tubes. After bleeding, ensure brake pedal is firm.

MASTER CYLINDER BLEEDING

Note. Master cylinder can be bled on vehicle or by using bench bleeding method.

ON VEHICLE BLEEDING

  1. Loosen one line nut on master cylinder. Wrap shop cloth around tubing below bitting to absorb escaping brake fluid. Depress brake pedal to floor by hand and hold. Tighten fitting.
  2. Release brake pedal. Do not release pedal until fitting is tightened or air will re-enter master cylinder. Repeat procedure until air no longer escapes from master cylinder. Repeat process for other line and ensure that brake pedal is firm.

BENCH BLEEDING

  1. Clamp master cylinder in vise by mounting flange. Install plugs in outlet ports. Fill reservoir with clean brake fluid. Loosen plug in rear port. Slowly depress piston slowly to force air from cylinder. Without releasing piston, tighten plug in outlet port.
  2. Repeat process until no air is released from port. Bleed front outlet port(s) using same method until all air is removed from cylinder.

MANUAL BLEEDING

Note. DO NOT allow master cylinder to run dry during bleeding. NEVER reuse brake fluid that has drained from brake system. When bleeding disc brakes, air may tend to cling to caliper walls. Lightly tap caliper while bleeding to aid in removal of air.

  1. Attach bleeder hose to right rear wheel cylinder and submerge end of hose in container partially filled with clean brake fluid. Loosen fitting about 3/4 turn and slowly depress brake pedal fully. Close bleeder and release brake pedal. Repeat until fluid is free of air bubbles.
  2. Repeat process for left rear wheel cylinder, right front caliper and left front caliper in that order. After completing bleeding procedure, ensure brake pedal is firm.

PRESSURE BLEEDING

Note. NEVER reuse brake fluid that has drained from brake system. Ensure bleeder tank has sufficient fluid to complete bleeding procedure. DO NOT exceed 50 psi of pressure in tank.

  1. On power brake equipped vehicles, release vacuum from booster by depressing brake pedal several times. Clean master cylinder cap and surrounding area. Remove cap. With pressure tank at least 1/2 full, connect to master cylinder with adapters. Attach bleeder hose to right rear wheel cylinder.
  2. Place other end of hose in clean container partially filled with clean brake fluid so end of hose is submerged in fluid. See «PRESSURE BLEEDER SETTINGS»(/ford/bronco-ii/i-1984-1990/remont/mechanical-hydraulic/#brake-system-bleeding) . Open release valve on pressure bleeder. PRESSURE BLEEDER SETTINGS Application Psi (kg/cm 2 ) All Models (1) 10-30 (.7-2.0) (1) NEVER exceed 50 psi.
  3. Unscrew bleeder valve 3/4-1 turn noting fluid flow. When fluid flowing from cylinder to jar is free of bubbles, close bleeder valve securely. Repeat process following proper bleeding sequence. See «BLEEDING SEQUENCE»(/ford/bronco-ii/i-1984-1990/remont/mechanical-hydraulic/#brake-system-bleeding) . BLEEDING SEQUENCE Application Sequence E Series Van RR, LR, RF, LF All Others (1) RR, LR, RABS Valve, RF, LF (1) RABS valve is located on frame rail ahead of rear axle. Valve is bled in same manner as wheel cylinders.

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