Volkswagen Workshop Service and Repair Manuals

Note:

For easier dismantling and assembling, it is more practical to remove the hydraulic unit complete with brake servo and brake master cylinder.

Removing

• ‒ Disconnect battery earth strap.
• ‒ Separate all electrical connections on ABS unit.
• ‒ Draw off as much brake fluid as possible from brake fluid reservoir using a suction bottle.
• ‒ Disconnect brake pipes from ABS unit and seal threaded holes with plugs from repair kit Part No. 1H0 698 311.
• ‒ Remove left-hand trim under dash panel.
• ‒ Disconnect brake pedal from brake servo unit
  =>Page 47-11.

• ‒ Remove hexagon nuts from brake servo/bulkhead.
• ‒ Carefully remove hydraulic unit and brake servo with brake master cylinder from engine compartment.

Installing

Notes:

• ◆ Hydraulic units supplied as replacement parts are already filled with hydraulic fluid and bled.
• ◆ Only remove sealing plugs on hydraulic unit when the relevant brake pipe is going to be fitted.
• ◆ If the sealing plugs are removed too early, brake fluid can escape, it is then no longer guaranteed that the unit is sufficiently filled or adequately bled.

• ‒ Preassemble hydraulic unit and brake servo with tandem master cylinder away from vehicle.

• ‒ Secure hydraulic unit, brake servo with tandem master cylinder to bulkhead.
• ‒ Fit brake pipes.
• ‒ Reconnect all electrical connections on ABS unit (ensure correctly connected).
• ‒ Bleed brake system =>Page 47-32.
• ‒ Install left-hand trim under dash panel.