Parts for your 2009 Subaru Exiga-Brake booster

2009 Subaru Exiga Brake Booster

Yes, the 2009 Subaru Exiga is fitted with a brake booster. Subaru’s YA-series Exiga factory service manual (Brake section, Power Assist) specifies a vacuum-type power brake booster mounted on the firewall behind the master cylinder, and Subaru’s electronic parts catalogue lists a “Booster Assy – Brake” for 2008–2012 Exiga models. Subaru Technical Information System materials for YA models also describe booster inspection and the one-way check valve, confirming this part is standard equipment.

On the Exiga, the brake booster (often called a brake servo) uses engine vacuum and a diaphragm to multiply the driver’s pedal effort, giving strong, progressive braking without needing to stand on the pedal. If assistance is lost, the pedal goes hard and stopping distances blow out — the brakes still work, but they’re a workout. Petrol Exiga variants use manifold vacuum with a check valve, turbo models may also employ an auxiliary vacuum source so assist remains consistent even under boost.

As part of routine servicing, it’s worth giving the booster setup a quick once-over. Inspect the vacuum hose from the intake to the booster for cracks, softness, or oil swelling, and make sure the clamps are snug. Listen at the firewall for any hiss with the engine running and pedal applied — that can point to a leaking diaphragm or grommet. A simple test: with the engine off, pump the pedal until it firms up, hold pressure, then start the engine, the pedal should drop slightly as assist kicks in. Any brake fluid weep at the rear of the master cylinder should be fixed promptly, as fluid can damage the booster.

Replacement is straightforward for a trained tech and doable at home with patience: disconnect the battery, unclip the pedal clevis under the dash, remove the four booster nuts, and carefully unbolt the master cylinder so it can be moved aside without kinking the lines. Swap the check-valve grommet, refit with correct pedal free play, and torque fasteners. If lines were opened, bleed the system. Quality OEM or reputable aftermarket boosters both suit Kiwi and Aussie roads.

• Common symptoms: hard pedal, longer stops, hissing at the firewall, idle changes when braking.
• Service tips: check hose and one-way valve every service, replace aged hoses/valves around the 10–15 year mark.

Popular questions about 2009 Subaru Exiga brake boosters

How can someone tell if their Exiga’s brake booster is failing?
A failing booster usually shows up as a firm, high brake pedal that takes more leg effort, plus a longer stopping distance. With the engine running, a hiss near the firewall can hint at a diaphragm or grommet leak. Try the quick test: pump the pedal with the engine off, hold pressure, then start — if the pedal doesn’t sink slightly, assist is weak or absent.

Can the brake booster be replaced at home?
Yes, if they’re comfortable working under the dash and around brake hydraulics. Expect 2–3 hours, mainly to access the pedal clevis and the four mounting nuts. It’s often possible to move the master cylinder aside without opening lines. Take care not to bend pipes, set correct pedal free play, and road-test in a safe area.

Does the 2009 Exiga use a vacuum or electric booster?
It uses a vacuum brake booster. Naturally aspirated versions rely on manifold vacuum with a one-way check valve, turbo variants may use an additional vacuum source to keep assistance consistent under boost. There’s no electric brake booster on this model range.