Coolant Reservoir

This procedure covers removal and replacement of the coolant reservoir (expansion tank) on a 2014-2019 Toyota Corolla with the 1.8L I4 engine.

Warnings

Tools required

Parts

• Coolant reservoir × 1 — Use OEM specification
• Reservoir cap × 1 — Use OEM or existing if undamaged

Fluids

• Toyota Super Long Life Coolant (Pink) — 2 qt

Preparation

1. Ensure the engine is completely cold before starting work
2. Park the vehicle on level ground and engage the parking brake
3. Open the hood and locate the coolant reservoir on the driver's side of the engine bay
4. Place a drain pan beneath the work area to catch any coolant spills

Procedure

1. 1

   Relieve cooling system pressure
   Slowly turn the coolant reservoir cap counterclockwise to release any residual pressure in the cooling system. Remove the cap completely once all pressure has been released.
2. 2

   Disconnect coolant hose from reservoir
   Locate the coolant hose connected to the lower portion of the reservoir. Use pliers to compress and slide the hose clamp away from the reservoir connection point. Gently twist and pull the hose off the reservoir nipple. Allow coolant to drain into the drain pan.
   Torque spec

   Hose Clamps4 Nm (3 lb-ft)
3. 3

   Disconnect overflow hose
   Locate the small overflow hose connected to the side or top of the reservoir. This hose typically runs down toward the ground. Pull the hose off the reservoir nipple by hand or use a flathead screwdriver to carefully pry it free.
4. 4

   Remove reservoir mounting bolts
   Using a 10mm socket and ratchet, remove the two mounting bolts securing the coolant reservoir to the body. On most models, one bolt is at the top and one near the bottom of the reservoir bracket.
   Torque spec

   Reservoir Mounting Bolts8 Nm (6 lb-ft)
5. 5

   Remove coolant reservoir
   Lift the reservoir straight up and out of the engine bay. Tilt it as needed to prevent spilling remaining coolant. Empty any residual coolant from the reservoir into the drain pan.
6. 6

   Install new coolant reservoir
   Position the new coolant reservoir into the mounting bracket location. Align the mounting holes with the body mounting points. Ensure the reservoir sits flush and is properly oriented with the filler neck facing upward.
7. 7

   Install reservoir mounting bolts
   Install the two reservoir mounting bolts and hand-tighten them. Using a torque wrench, tighten both bolts to 8.0 Nm (6.0 lb-ft) in a cross pattern to ensure even seating.
   Torque spec

   Reservoir Mounting Bolts8 Nm (6 lb-ft)
8. 8

   Reconnect overflow hose
   Push the overflow hose firmly onto the reservoir nipple until it is fully seated. Ensure the hose is routed properly and does not contact any hot engine components.
9. 9

   Reconnect coolant hose
   Push the main coolant hose firmly onto the lower reservoir nipple until it bottoms out. Slide the hose clamp back into position over the hose and reservoir connection. Position the clamp approximately 10mm from the end of the hose and tighten to 4.0 Nm (3.0 lb-ft).
   Torque spec

   Hose Clamps4 Nm (3 lb-ft)
10. 10

    Refill cooling system
    Using a funnel, add Toyota Super Long Life Coolant (Pink) to the reservoir until the level reaches the FULL line. Do not overfill. Install the reservoir cap and turn it clockwise until it clicks into place.
11. 11

    Bleed air from cooling system
    Start the engine and allow it to idle with the heater set to maximum temperature. Monitor the coolant level in the reservoir. As the engine warms and the thermostat opens, the coolant level may drop. Add coolant as needed to maintain the proper level. Run the engine until the cooling fan cycles on, indicating the system has reached operating temperature.

Reassembly

1. Verify all hose connections are secure and clamps are properly positioned
2. Ensure the reservoir cap is installed correctly and fully seated
3. Clean up any spilled coolant from the engine bay and surrounding components

Verification

• Check the coolant level in the reservoir with the engine cold - it should be at the FULL line
• Inspect all hose connections for leaks with the engine running at operating temperature
• Verify the cooling fan operates normally when the engine reaches operating temperature
• Check for coolant leaks around the reservoir mounting area and hose connections after a test drive
• Confirm the heater produces hot air when set to maximum temperature

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