WrxBuild.com Service & Build Log

SEC 04 · Procedure

Brake Fluid Flush and Bleed (With ABS)

Two-year-old brake fluid is brown and boils early. A full flush with correct bleed order, by hand or with a cheap pressure bleeder.

Procedure

  1. Baster out the old reservoir fluid down to the strainer and refill with fresh - no point pushing brown fluid through the whole system.
  2. Bleed order for most Subarus is furthest-to-nearest from the master: RR, LR, RF, LF? No - check your FSM; many Subarus specify FL-FR-RL-RR or a diagonal pattern. When in doubt, furthest line first never hurts.
  3. Crack each bleeder with tubing into a bottle; helper presses slowly and holds while you close, or the pressure bleeder does it alone. Never let the reservoir run dry - that puts air in the ABS unit.
  4. Watch the tube, not the clock: bleed each corner until the fluid runs clear and bubble-free, topping the reservoir every few strokes.
  5. Do not crush the bleeder screws - snug plus a touch. Cap each nipple after; open nipples rust solid.
  6. Pedal should be high and hard before the car moves. Spongy after a clean bleed means air remains - repeat the corner nearest the master.
  7. This is maintenance bleeding only. If the ABS unit itself was opened or ran dry, some cars need an ABS-cycled bleed with a scan tool - know which job you're doing.

Work at your own risk. Torque values and procedures vary by vehicle — always confirm against the factory service manual for your exact model.

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