Parts for your 2009 Subaru Forester-Cluth slave cylinder

2009 Subaru Forester cluth-slave-cylinder — what’s fitted and what to do about it

Based on the Subaru Factory Service Manual for the SH-series 2009 Forester (Clutch section), the Subaru Technical Information System (STIS), and the Subaru genuine parts catalogue, manual-transmission models use a hydraulic clutch with a master cylinder and a release cylinder (commonly called the clutch slave cylinder). Automatic models don’t use a cluth-slave-cylinder at all, as the torque converter handles drive engagement.

For 5-speed manual 2009 Foresters, the cluth-slave-cylinder (clutch slave cylinder) is a small hydraulic actuator that converts pressure from the clutch master cylinder into movement at the clutch fork. That movement disengages the clutch so gears can be selected smoothly. It’s a simple bit of kit but it cops heat, vibration and grime under the bonnet and on the bellhousing, so staying on top of it saves headaches down the track.

As part of routine servicing, the forecourt check should include a look at the clutch fluid level and condition in the reservoir, and a quick inspection around the slave cylinder for dampness, perishing of the rubber boot, or paint peeled by fluid. If the fluid’s dark or contaminated, a flush with the correct spec brake fluid (DOT 3 or DOT 4, as marked on the cap or FSM) keeps the seals happy. Many workshops in Australia and New Zealand aim for a clutch fluid change roughly every 2 years or 40,000 km, or sooner if the vehicle sees lots of stop–start city work or towing.

Telltale signs the cluth-slave-cylinder is on the way out include a soft or spongy pedal, a bite point that wanders, difficulty selecting gears, or visible leaks at the bellhousing. If any of that pops up, it’s worth booking the car in before it strands someone at the lights.

Replacing the cluth-slave-cylinder is a tidy job for a competent tech. After confirming the vehicle is the 5-speed manual, they’ll safely raise the car as needed, cap and protect paintwork, then crack the hydraulic line at the slave, remove the mounting bolts, and swap in a quality OEM or reputable aftermarket unit with a fresh boot and pushrod. Bleeding the system is critical: keep the reservoir topped, bleed until air-free fluid runs, and confirm a consistent pedal and clean engagement. Final checks include looking for leaks under pressure and ensuring the pedal free play matches the service manual. Where torque specs or procedures differ by market or VIN, the FSM for the exact SH model should be followed to the letter.

A quick visual at each service, clean fresh fluid, and prompt attention to leaks will see the cluth-slave-cylinder do long, drama-free kilometres.

• Symptoms to watch: spongy pedal, low fluid, clutch slip on disengage, damp slave cylinder or bellhousing.
• Service tips: use the correct fluid, don’t mix types, and avoid spilling on paint.
• Parts choice: OEM or known-brand aftermarket, and replace the rubber boot if it’s cracked.

Note: Automatic 2009 Foresters don’t have a cluth-slave-cylinder because they use a torque converter, not a manual clutch.

Popular questions about the 2009 Subaru Forester cluth-slave-cylinder

How can someone tell if their 2009 Forester actually has a cluth-slave-cylinder?
If it’s a 5-speed manual, it does. Under the bonnet there’ll be a clutch fluid reservoir, and down on the gearbox bellhousing there’s a small cylinder with a hydraulic line going into it and a pushrod into the clutch fork. If it’s an automatic, there’s no clutch pedal, no clutch reservoir, and no cluth-slave-cylinder.

What fluid should be used in the cluth-slave-cylinder system, and how often should it be changed?
Use the brake fluid grade specified on the cap or in the Subaru service manual—typically DOT 3 or DOT 4. In Aussie and Kiwi conditions, changing clutch fluid about every 2 years or 40,000 km is a safe bet, sooner if the fluid looks dirty or the vehicle tows or lives in heavy traffic.

Does the clutch need bleeding after replacing the cluth-slave-cylinder?
Yes. After fitting the new slave, the system must be bled to remove trapped air or the pedal will feel spongy and the clutch won’t disengage cleanly. Keep the reservoir topped, bleed until bubbles are gone and pedal feel is firm, then recheck for leaks and correct free play per the factory manual.