Hydraulic unit accumulator (ABS) - removal and refitting

Note: A new O-ring must be used between the accumulator and the hydraulic unit on refitting.

Caution: Refer to the
precautions in Section 1.

Removal
1 Disconnect the battery negative lead.

2 Depressurise the hydraulic system by pumping the brake pedal at least 20 times, or until it becomes hard.

3 Wrap a clean rag round the base of the accumulator to catch any spilt fluid.

4 Unscrew the accumulator using a hexagon key. Remove the accumulator, noting the sealing ring and being prepared for fluid spillage (see illustration). If fluid is accidentally spilt on the paintwork, wash off immediately with cold water.

17.4 Unscrew the accumulator and remove it, noting the O-ring (arrowed)
17.4 Unscrew the accumulator and remove it, noting the O-ring (arrowed)

Refitting
5 Fit a new O-ring to the base of the accumulator, fit the accumulator and tighten it.

6 Reconnect the battery. Switch on the ignition and check that the hydraulic unit pump stops within 60 seconds; if not, the accumulator is likely to be faulty.

7 On completion, bleed the complete hydraulic system and check for leaks around all disturbed components.

    See also:

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