Parts for your 2016 Subaru Forester-Brake booster

2016 Subaru Forester brake booster — what it does and how to look after it

Yes, the 2016 Subaru Forester is fitted with a vacuum brake booster. This is documented in the Subaru Service Manual for the SJ-series (Brake > Power Assist System) and shown in the Subaru parts catalogue as the “Brake Booster Assembly” for 2016 Forester variants. Petrol models use intake manifold vacuum (turbo and diesel variants may use a vacuum pump), but all of them rely on a booster to reduce pedal effort.

What’s the point of the brake booster? It uses engine vacuum and a diaphragm to amplify the force from the driver’s foot, so stopping feels easy and predictable without having to stand on the pedal. A one-way check valve holds vacuum in the booster, so you still get assistance for a couple of presses even if the engine stalls. It’s one of those parts you don’t notice until it’s not doing its job.

It’s not a routine replacement item, but it does deserve attention at service time. A quick functional check is easy: with the engine off, pump the pedal a few times to deplete vacuum, hold light pressure, then start the engine — the pedal should drop slightly as vacuum assist kicks in. While the bonnet’s up, a tech should inspect the vacuum hose, check valve and grommets for cracks or loose fits, and listen for any hissing around the booster firewall area.

Signs it’s on the way out include a rock-hard pedal with higher effort, longer stopping distances, a constant hiss near the pedal, or a rough/high idle from a vacuum leak. If the pedal is hard and the car’s tough to pull up, it’s not safe to keep driving — organise a tow.

• When replacement’s needed:
  • Use quality OEM-equivalent boosters and a new check valve/gasket.
  • Set the pushrod length to spec from the Subaru workshop manual to avoid dragging brakes or excess free play.
  • If the master cylinder comes off, bench-bleed it and bleed the system afterwards, watch for ABS bleed procedures.
• Good workshop habits:
  • Torque the mounting nuts correctly and recheck pedal feel and booster hold vacuum after a road test.
  • In AU/NZ, a faulty booster can fail a roadworthy/WoF, so timely repair keeps the Forester legal and safe.

Technical sources referenced: Subaru Service Manual (2016 Forester SJ — Brake > Power Assist System) and Subaru genuine parts catalogue listings for “Brake Booster Assembly” applicable to 2016 Forester engines.

Popular questions about 2016 Subaru Forester brake boosters

Does a 2016 Subaru Forester have a brake booster?
Yes. The SJ-series 2016 Forester uses a vacuum-assisted brake booster across petrol, turbo and diesel variants. This is shown in Subaru’s service manual under the power assist section and in the Subaru parts catalogue.

What are common symptoms of a failing brake booster on a 2016 Forester?
A hard brake pedal, longer stopping distances, a constant hissing sound near the pedal/firewall, or a rough/high idle from a vacuum leak. The pedal should also drop slightly when starting the engine after being pumped with the engine off—if it doesn’t, assistance may be low.

How much does replacement usually cost and how long does it take?
A typical workshop allows about 1.5–3.0 hours. Parts vary widely: quality aftermarket or OEM boosters can range roughly AUD/NZD $400–$1,000+, depending on supplier and variant. Labour rates differ by region, so it’s smart to get a firm quote. Always include a new check valve and inspect the vacuum hose.