🔧 Forester - CVT Transmission Fluid Drain & Fill

Your Forester uses a Subaru Lineartronic CVT (continuously variable transmission). A proper fluid service is a drain & fill with a temperature-based level check (there’s no dipstick), so the CVT fluid temperature matters to get the level right.

Difficulty Level: Advanced | Estimated Time: 1.5-3.0 hours

Assumption: TR690 Lineartronic CVT with drain/fill/overflow plugs (typical for your Forester).

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⚠️ Safety & Precautions

• ⚠️ Work on a level surface; CVT level is very sensitive to tilt.
• ⚠️ CVT fluid gets hot; wear gloves and safety glasses to avoid burns.
• ⚠️ Use jack stands; never rely on a floor jack alone.
• ⚠️ Keep the engine running only when instructed; stay clear of belts/fans.
• ⚠️ Use only Subaru-approved CVT fluid; the wrong fluid can damage the CVT.
• 🔌 Battery disconnect is not required for this service.

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🔧 Required Tools

You'll need the following tools for this repair:

• Floor jack (rated 3-ton minimum)
• Jack stands (2-ton minimum, pair)
• Wheel chocks
• Safety glasses
• Nitrile gloves
• Trim clip removal tool
• Socket set (8mm-14mm)
• Ratchet (3/8")
• Torque wrench (10-100 ft-lbs)
• Drain pan (10-quart minimum)
• Fluid transfer pump (specialty)
• OBD-II scan tool with CVT fluid temp data (specialty)
• Funnel with hose (long-neck)
• Shop rags
• Brake cleaner spray

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Subaru CVT fluid (Subaru CVTF-II) - Qty: 7 quarts
• Drain plug crush washer - Qty: 1
• Fill plug crush washer - Qty: 1
• CVT overflow/check plug crush washer - Qty: 1

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📋 Before You Begin

• Park on level ground, set the parking brake, and chock the rear wheels.
• Raise the front with a floor jack and support with jack stands; keep the vehicle as level as possible (front-to-rear).
• Set up your OBD-II scan tool to read CVT fluid temperature (this is the CVT’s internal fluid temp reading).
• Have a clean drain pan and measure container ready so you can compare drained vs filled.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Remove the lower splash shield

• Use a trim clip removal tool to pop the plastic clips.
• Use an 10mm socket and ratchet to remove any bolts, then remove the shield.

Step 2: Identify the CVT drain, fill, and overflow/check plugs

• Use a shop rag and brake cleaner spray to clean around the plugs first (keeps dirt out).
• The CVT typically has a drain plug on the bottom of the case, a fill plug on the side, and an overflow/check plug used to set final fluid level.

Step 3: Loosen the fill plug first (important)

• Place the drain pan underneath as a precaution.
• Use the appropriate socket and a ratchet to crack the fill plug loose first.
• If the fill plug won’t loosen, stop here.

Step 4: Drain the old CVT fluid

• Position the drain pan (10-quart minimum) under the drain plug.
• Use the appropriate socket and ratchet to remove the drain plug and let it drain fully.
• Measure how much drained out using your container (helps prevent under/overfilling).

Step 5: Reinstall the drain plug with a new crush washer

• Install a new drain plug crush washer on the drain plug.
• Thread the plug in by hand, then tighten with a torque wrench.
• Torque to 50 Nm (37 ft-lbs)

Step 6: Add new CVT fluid (initial fill)

• Remove the fill plug fully using the appropriate socket and ratchet.
• Use a fluid transfer pump (specialty) to pump in Subaru CVTF-II.
• Add roughly the same amount you drained out as your starting point.
• Install a new fill plug crush washer and reinstall the fill plug.
• Torque to 50 Nm (37 ft-lbs)

Step 7: Warm the CVT fluid and circulate it

• Start the engine and keep your foot on the brake.
• With the engine idling, move the shifter slowly through P-R-N-D, pausing 2-3 seconds in each position, then return to P.
• Use the OBD-II scan tool with CVT fluid temp data (specialty) to monitor CVT fluid temperature.
• Target the level-check temperature window: 35°C to 45°C (95°F to 113°F).

Step 8: Set the final fluid level using the overflow/check plug

• With the engine idling and CVT temp in the 35°C to 45°C range, place the drain pan under the overflow/check plug.
• Use the appropriate socket and ratchet to remove the overflow/check plug carefully.
• Correct level behavior:
  • If fluid dribbles out and then becomes a thin stream/drip, that’s normal.
  • If nothing comes out, add fluid through the fill port using the fluid transfer pump (specialty), then recheck.
  • If it pours out heavily, let it drain until it becomes a thin stream/drip.
• Install a new overflow/check plug crush washer and reinstall the overflow/check plug.
• Torque to 25 Nm (18 ft-lbs)

Step 9: Reinstall the splash shield

• Reinstall the shield using the 10mm socket and ratchet.
• Reinstall clips using the trim clip removal tool.

Step 10: Lower the vehicle

• Use the floor jack to lift slightly, remove the jack stands, then lower the vehicle.

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✅ After Repair

• Start the engine and check underneath for leaks with a flashlight (if available) and shop rags.
• Take a 10-15 minute test drive. Keep it gentle; no hard acceleration.
• Park on level ground and recheck for seepage around the drain/fill/overflow plugs.
• Dispose of old CVT fluid properly.

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💰 DIY vs Shop Cost

Shop Cost: $300-$600 (parts + labor)

DIY Cost: $90-$180 (parts only)

You Save: $210-$420 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 1.5-3.0 hours.

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🎯 Ready to get started?

HowToo makes it easy: same-day/2-day shipping on every part, plus all the tools and specialty tools you need! Check out the parts and tools sections below to add everything to your cart.