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Pressure Adjustment

NOTE: For following procedure, vehicle must be empty, have full fuel tank and be resting on wheels. The 4000CS Quattro and 5000CS Quattro has a nonadjustable regulator.
  1. Disconnect parking brake cable at left rear caliper on 4000CS Quattro models. On all models except 4000CS Quattro and 5000CS connect pressure gauges at left front and right rear wheels. On 4000CS Quattro, connect gauges to left front and left rear. On 5000CS, connect gauges to rear wheels only. Bleed gauges and hoses through bleeders on gauges. Have assistant of about 165 lbs. sit in driver's seat. Bounce rear of car several times.
  2. On all models except 5000CS Quattro, depress brake pedal several times until gauge at front axle shows reading of 725 psi (50 bar). On 5000CS Quattro, go to step 6). On 4000CS Quattro models, gauge at rear axle should show reading of 508-566 psi (32-39 bar). On 5000CS Turbo, reading should show 507-653 psi (35-45 bar). On all other models, gauge at rear axle should show reading of 471-616 psi (32.5-42.5 bar).
  3. Increase pressure on brake pedal until gauge at front axle shows reading of 1450 psi (100 bar). On 4000CS Quattro models, gauge at rear axle should show reading of 841-899 psi (58-62 bar). On 5000CS Turbo, gauge should read 827-1059 psi (57-73 bar). On all other moedls, gauge at rear axle should show reading of 783-1037 psi (54.0-71.5 bar).
  4. If pressure at rear axle is higher than specification, spring tension on brake pressure regulator is too high. If pressure at rear axle is lower than specification, spring tension on brake pressure regulator is too low. On all models except 4000CS Quattro, adjust regulator by changing spring tension.
  5. Have assistant release pressure on brake pedal. Adjust tension on pressure regulator spring according to reading at rear axle. Repeat pressure test. If pressure cannot be correctly adjusted, replace brake pressure regulator. If pressure can be adjusted correctly, remove gauges. Bleed hydraulic brake system. Reconnect parking brake cable on 4000CS Quattro models.
  6. On 5000CS Quattro, depress brake pedal until gauge reading on left rear wheel is 580 psi (40 bar). Reading at right rear wheel should be 217-362 psi (15-25 bar). If not, replace pressure regulator.
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