This procedure covers the removal and replacement of transmission cooler lines on the 2018-2024 Toyota Camry with 2.5L I4 engine, including proper fluid refilling and leak verification.

Warnings

Tools required

Parts

• Transmission cooler line set × 1 — Use OEM Toyota part or equivalent
• Transmission cooler line O-rings × 4 — Usually included with cooler lines
• Transmission drain plug crush washer × 1 — 90430-12031 or equivalent

Fluids

• Toyota WS ATF — 2 qt

Preparation

1. Park vehicle on level surface and engage parking brake
2. If engine is warm, allow minimum 30 minutes cooling time
3. Raise front of vehicle with floor jack and support securely on jack stands at manufacturer-specified lift points
4. Remove plastic engine undercover (10mm bolts) to access transmission and cooler lines
5. Place large drain pan beneath transmission cooler line connections

Procedure

1. 1

   Locate and inspect transmission cooler lines
   Identify the two transmission cooler lines running from the left side of the transmission to the radiator. The lines connect to the transmission via quick-connect fittings. Inspect the routing and note any clips or brackets securing the lines along their path. On the 2018-2024 Camry, the lines typically route along the front of the transmission and up toward the radiator.
2. 2

   Disconnect cooler lines at radiator
   Position drain pan beneath radiator cooler line connections. The radiator end uses threaded fittings with O-rings. Use a 14mm wrench to carefully loosen and disconnect both cooler lines from the radiator-mounted transmission cooler. Allow fluid to drain completely. Cap or plug radiator ports to prevent contamination.
   ⚠Expect approximately 1-2 quarts of ATF to drain from the lines. Ensure drain pan is properly positioned.
3. 3

   Remove line mounting brackets and clips
   Working from radiator toward transmission, remove all mounting clips and brackets securing the cooler lines. Most clips are push-type plastic fasteners that can be removed by prying the center pin up, then extracting the clip body. Note the exact position of each clip for reinstallation. Some metal brackets may use 10mm bolts.
4. 4

   Disconnect cooler lines at transmission
   Position drain pan directly beneath transmission cooler line connections on the left side of the transmission case. Insert the appropriate size transmission line disconnect tool into the quick-connect fitting. Push the tool in while simultaneously pulling the cooler line straight out. Repeat for the second line. Additional fluid will drain from the transmission and lines.
   ⚠Do not twist or bend lines during removal. Pull straight out to avoid damaging transmission case ports.
5. 5

   Remove old cooler lines
   Carefully maneuver the old cooler lines out from the engine bay, noting their exact routing path. Take photos if necessary for reference during installation. Inspect the removed lines for signs of chafing, cracking, or damage that may have caused the failure.
6. 6

   Clean connection points
   Use a clean shop towel to wipe the transmission case cooler line ports clean. Inspect O-ring sealing surfaces for damage or debris. Clean the radiator cooler ports with brake cleaner and allow to dry. Check that no metal shavings or contamination entered the transmission or radiator during line removal.
7. 7

   Prepare new cooler lines
   Unpack new cooler lines and verify correct part numbers for your vehicle. Install new O-rings on the radiator end fittings if not pre-installed. Lightly lubricate O-rings with clean ATF. Install new O-rings on the quick-connect ends that mate to the transmission if provided separately.
8. 8

   Route and install new cooler lines
   Route the new cooler lines along the exact path of the original lines, ensuring they do not contact sharp edges or hot exhaust components. Connect the quick-connect fittings to the transmission first by pushing them straight in until you hear or feel a distinct click. Verify connection by pulling back on each line - it should not separate.
9. 9

   Connect cooler lines to radiator
   Thread the cooler line fittings into the radiator-mounted transmission cooler ports by hand to avoid cross-threading. Use a 14mm wrench to snug the connections, then torque appropriately. Do not overtighten as this may damage O-rings. The connection should be snug but requires moderate effort only.
   ℹ️No specific torque value provided for radiator cooler line fittings. Tighten to snug plus 1/4 turn after O-ring contact.
10. 10

    Reinstall mounting brackets and clips
    Reinstall all mounting clips and brackets in their original positions to secure the cooler lines. Ensure lines are properly supported and cannot vibrate against other components. Push-type clips should be fully seated and center pins pressed down to lock. Any metal brackets should be torqued to 11 Nm if using cover screw specification.
    Torque spec

    Cover Screws11 Nm (8 lb-ft)
11. 11

    Refill transmission fluid
    Remove transmission fill plug located on the transmission case and insert a long-spout funnel. Add approximately 2 quarts of Toyota WS ATF to replace fluid lost during line replacement. Start with less than the estimated amount as you will verify level with engine running. Reinstall fill plug with proper torque.
    Torque spec

    Fill Plug34 Nm (25 lb-ft)
12. 12

    Check for leaks - initial inspection
    With vehicle still raised and supported, start the engine and allow it to idle. Shift through all gear positions (P-R-N-D-L) pausing 3 seconds in each, then return to Park. Inspect all cooler line connections at both transmission and radiator for any signs of leakage. Tighten connections if seepage is observed.
13. 13

    Verify and adjust fluid level
    With engine at operating temperature and idling in Park on level ground, check transmission fluid level per Toyota procedure. Remove fill plug - fluid should be at bottom edge of fill hole. Add fluid as needed in small increments. Reinstall fill plug with proper torque when level is correct.
    ℹ️Transmission fluid level must be checked with engine running and transmission at operating temperature (160-180°F).
    Torque spec

    Fill Plug34 Nm (25 lb-ft)

Reassembly

1. Reinstall plastic engine undercover using 10mm bolts
2. Lower vehicle from jack stands and remove jack
3. Wipe up any spilled transmission fluid from under vehicle and engine bay
4. Double-check that all tools and materials are removed from engine compartment

Verification

• Test drive vehicle for at least 10 miles including highway speeds to fully circulate transmission fluid through cooler system
• After test drive, re-inspect all cooler line connections for any signs of leakage with vehicle raised
• Verify transmission shifts smoothly through all gears with no slipping or delayed engagement
• Recheck transmission fluid level after test drive and top off if necessary
• Monitor for leaks over the next few days of normal driving

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