This procedure covers the removal and replacement of the transmission oil cooler on a 2019-2024 Toyota RAV4 with the 2.5L I4 gasoline engine and FWD configuration.

Warnings

Tools required

Parts

• Transmission oil cooler × 1 — Use OEM specification
• Transmission cooler line O-rings × 2 — Use OEM specification
• Transmission drain plug crush washer × 1 — Use OEM specification
• Engine coolant (if draining radiator) × 1 — Toyota Super Long Life Coolant (Pink)

Fluids

• Toyota WS ATF — 4 qt

Preparation

1. Park vehicle on level ground and engage parking brake
2. Allow engine and transmission to cool completely (minimum 2 hours after operation)
3. Raise vehicle using floor jack and support securely on jack stands at manufacturer lift points
4. Remove engine splash shield and lower covers to access transmission and radiator area
5. Place large drain pan under transmission drain plug
6. Disconnect negative battery terminal

Procedure

1. 1

   Drain transmission fluid
   Locate the transmission drain plug on the bottom of the transmission pan. Remove the drain plug using a 14mm socket and allow all fluid to drain into the catch pan. This will take several minutes. Once drained, install a new crush washer on the drain plug and reinstall, torquing to specification.
   Torque spec

   Transmission Drain Plug30 Nm (22 lb-ft)
2. 2

   Access transmission cooler lines
   From underneath the vehicle, locate the transmission cooler lines running from the transmission to the radiator on the passenger side. The lines connect to the lower portion of the radiator assembly. Clean the area around the connection points to prevent contamination.
3. 3

   Disconnect lower transmission cooler line
   Using a line wrench, carefully loosen the lower transmission cooler line fitting at the radiator. Be prepared for residual fluid to drain. Once loosened, remove the line completely and cap or plug the transmission-side connection to prevent contamination. Inspect the O-ring on the line and set aside for replacement.
   ⚠Use line wrenches (flare nut wrenches) to prevent rounding off the cooler line fittings. Standard open-end wrenches can damage the soft aluminum fittings.
4. 4

   Disconnect upper transmission cooler line
   Repeat the disconnection process for the upper transmission cooler line. Use a line wrench to loosen the fitting at the radiator, allow residual fluid to drain, and remove the line. Cap or plug both the line and radiator port. Remove and discard the O-ring from this line as well.
5. 5

   Remove transmission oil cooler from radiator
   The transmission oil cooler is integrated into the side tank of the radiator. Remove the mounting bolts securing the cooler assembly to the radiator using a 10mm socket. On this model, there are typically 2-3 mounting bolts. Carefully pull the cooler assembly away from the radiator, being mindful of any remaining fluid. Note the orientation and position of any gaskets or seals.
   ℹ️If cooler is severely damaged or corroded into the radiator, radiator replacement may be necessary. Inspect radiator mounting area carefully.
6. 6

   Clean mounting surfaces
   Thoroughly clean the mounting surface on the radiator where the new cooler will be installed. Remove any old gasket material, debris, or corrosion using a plastic scraper. Wipe clean with shop towels. Inspect the radiator mounting area for any cracks or damage.
7. 7

   Install new transmission oil cooler
   Position the new transmission oil cooler onto the radiator mounting surface, ensuring proper alignment with the coolant passages and mounting holes. Install new gaskets or O-rings as specified by the replacement cooler. Install mounting bolts finger-tight initially, then torque to specification in a cross-pattern.
   Torque spec

   Mounting Bolts27 Nm (20 lb-ft)
8. 8

   Reconnect transmission cooler lines
   Install new O-rings on both transmission cooler line fittings, lubricating them lightly with clean ATF. Connect the upper cooler line first, threading by hand to ensure proper engagement. Tighten with a line wrench until snug. Repeat for the lower cooler line. Do not overtighten as this can damage the aluminum fittings.
   ⚠Always use new O-rings on cooler line connections. Old O-rings will leak. Lubricate O-rings with clean ATF before installation.
9. 9

   Reinstall underbody covers
   Reinstall the engine splash shield and any lower covers that were removed for access. Ensure all fasteners are properly secured.
10. 10

    Refill transmission fluid
    Lower the vehicle to the ground. Locate the transmission fill plug (typically on the side of the transmission housing, accessed from above or below). Using a fluid pump or funnel with hose, add approximately 4 quarts of Toyota WS ATF initially. Start the engine and allow it to reach operating temperature while cycling through all gear positions (P-R-N-D and back to P), pausing 2-3 seconds in each gear.
    ⚠Only use Toyota WS ATF. Other fluids are not compatible and will cause transmission damage. Do not overfill.
11. 11

    Check and adjust fluid level
    With the engine running and transmission in Park, check the fluid level according to Toyota's procedure for this model (typically requires a specific temperature range of 104-122°F). Add fluid as needed to reach the proper level. The total capacity is approximately 10 quarts, but you may only need 3-4 quarts depending on how much remained in the system.
    ℹ️This transmission uses a fill-to-overflow method. Follow Toyota's specific procedure for proper fluid level checking, which requires the transmission to be at operating temperature.

Reassembly

1. Reconnect negative battery terminal
2. Verify all cooler line connections are tight and properly secured
3. Ensure all underbody covers and splash shields are reinstalled
4. Double-check transmission fluid level after test drive

Verification

• Start the engine and inspect all cooler line connections for leaks while engine is running
• Check transmission drain plug for leaks
• Test drive the vehicle for 10-15 minutes, allowing transmission to reach full operating temperature and shift through all gears normally
• After test drive, recheck transmission fluid level and top off if necessary
• Inspect underneath vehicle one final time for any signs of ATF leakage around cooler connections
• Verify transmission shifts smoothly and no warning lights are present on dashboard

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