Replacement of accessible low-voltage coolant lines (powertrain/radiator side) on a 2024 Model 3 Performance AWD. This procedure covers non-HV coolant plumbing only — any line connecting to the HV battery pack, octovalve, or drive unit internals is out of scope.

Warnings

Tools required

Parts

• Replacement coolant line(s) — manufacturer-specified for 2024 Model 3 Performance × 1 — Refer to Tesla EPC for the specific line being replaced
• Quick-disconnect O-rings / seals (replace any disturbed) × 1 — OEM coolant line seal kit
• Worm-gear or constant-tension hose clamps (if disturbed) × 2 — OEM-spec replacement clamps

Fluids

• Tesla Battery/Motor Coolant (G-48 spec) — 10 qt

Preparation

1. Park on level ground, place in P, engage parking brake.
2. Exit ALL doors with the key fob away from the vehicle. Wait at least 2 minutes for HV systems to fully de-energize, even on this non-HV job.
3. Disconnect the 12V low-voltage battery. On 2024 Model 3, the 12V (lithium on most build configurations) is located under the rear seat or rear floor area — verify location before access and disconnect negative first.
4. DO NOT touch, cut, or pierce ANY orange cable — these are high-voltage and lethal.
5. If at any point you encounter an orange cable, an HV component, or are unsure if a system is de-energized: STOP and consult a Tesla-certified technician.
6. Allow the vehicle to cool fully — coolant system can be warm even hours after driving due to thermal management cycles.
7. Identify the exact coolant line to be replaced and confirm it is on the powertrain/radiator low-voltage side, not the HV battery loop.
8. Raise the vehicle on a lift or stands using Tesla-specified jack pad locations only — lifting on the battery pack or pinch welds will damage the floor structure.
9. Remove the front underbody aero shield and any wheel-well liners required to access the target coolant line.

Procedure

1. 1

   Identify and verify the target coolant line
   Trace the coolant line from end to end. Confirm both ends terminate at non-HV components (e.g. front radiator, expansion tank, coolant pump on the powertrain side, condenser sub-circuit). If either end disappears into the HV battery pack, the octovalve, or the drive unit, abort this procedure.
   ⚠️If the line is part of the HV thermal loop or octovalve circuit, this job is dealer-only.
2. 2

   Drain coolant from the affected circuit
   Position a clean catch pan beneath the lowest point of the circuit. Open the expansion tank cap slowly to relieve any residual pressure. Loosen the lowest accessible fitting on the target line to drain. Capture all coolant — do not allow it to contact HV connectors or the battery pack seam.
3. 3

   Remove obstructing covers and brackets
   Remove plastic covers, air ducting, or splash shields covering the line routing. Set fasteners aside in labeled order. If a structural bracket retains the line, remove it now.
   Torque spec

   Cover Screws11 Nm (8 lb-ft)

   Bracket Bolts20 Nm (15 lb-ft)
4. 4

   Disconnect any sensors on the line
   If the line carries an inline coolant temperature sensor or flow sensor, unclip the connector and remove the sensor (or leave it attached to the harness if the line slides free of it). Cap the sensor port to prevent contamination.
   Torque spec

   Sensor Bolts11 Nm (8 lb-ft)
5. 5

   Release quick-disconnect fittings
   Tesla coolant lines commonly use squeeze-tab or collar-style quick-disconnects. Use the correct release tool — do not pry with screwdrivers, which crack the plastic body. Pull the line straight off without side-loading. Inspect each fitting for cracks; replace any that are damaged.
   Torque spec

   Coolant Line Fittings15 Nm (11 lb-ft)
6. 6

   Loosen and remove hose clamps (if applicable)
   For sections retained by worm-gear or constant-tension clamps, slide the clamp back along the hose and work the hose off the barb with a gentle twisting motion. Replace any clamp that is corroded or distorted.
   Torque spec

   Hose Clamps3 Nm (2 lb-ft)
7. 7

   Remove the coolant line from the vehicle
   Free the line from any retainer clips along its routing path. Note the orientation, clip locations, and any heat-shield routing — photograph if needed. Remove the line.
8. 8

   Inspect mating surfaces and seals
   Wipe each fitting port clean with a lint-free cloth. Inspect O-ring grooves for nicks or debris. Replace all O-rings on disturbed quick-disconnects — do not reuse.
9. 9

   Install the new coolant line
   Lubricate new O-rings with a small amount of fresh coolant only (no petroleum grease — it degrades EPDM seals). Route the new line exactly as the original, seating it into all retainer clips. Engage each quick-disconnect until you hear/feel a positive click, then tug-test to confirm lock.
   Torque spec

   Coolant Line Fittings15 Nm (11 lb-ft)
10. 10

    Reinstall clamps, sensors, and brackets
    Reinstall any hose clamps, inline sensors, and support brackets removed earlier. Torque each fastener to the verified specification.
    Torque spec

    Hose Clamps3 Nm (2 lb-ft)

    Sensor Bolts11 Nm (8 lb-ft)

    Bracket Bolts20 Nm (15 lb-ft)

    Connector Bolts7 Nm (5 lb-ft)
11. 11

    Reinstall covers and shields
    Reinstall any plastic covers, air ducting, or splash shields removed for access. Ensure all clip-in tabs seat fully before tightening screws.
    Torque spec

    Cover Screws11 Nm (8 lb-ft)
12. 12

    Vacuum-fill the cooling circuit
    Connect a vacuum fill tool to the expansion tank. Pull a vacuum to the tool manufacturer's specification and verify it holds (a pressure rise indicates a leak — locate and correct before filling). Draw in fresh Tesla-spec G-48 coolant until the system is full and the tank is at the correct cold-fill level.

Reassembly

1. Confirm the expansion tank cap is properly seated and locked.
2. Reinstall the front underbody aero shield with all original fasteners — missing fasteners cause range loss and shield flap at highway speed.
3. Lower the vehicle to the ground.
4. Reconnect the 12V low-voltage battery (positive first, then negative), and ensure the battery hold-down is reinstalled.
5. Allow the vehicle to wake fully and clear any transient alerts on the center display.

Verification

• Power the vehicle on and let the thermal management system run. The 2024 Model 3 will cycle coolant through the affected circuit automatically — listen for pump operation and feel for warming/cooling at the lines.
• Check the center display for any thermal system, coolant level, or coolant temperature alerts. Any persistent alert indicates incomplete bleed or an installation issue.
• Inspect every disturbed fitting for leaks after 10 minutes of system operation, then again after a short test drive.
• Recheck the expansion tank level cold the next day and top up to the cold-fill mark with Tesla-spec G-48 coolant if needed.
• Document the service in the owner's records. Tesla now recommends coolant inspection at 4 years / 50,000 mi — set the next inspection reminder accordingly.
• If the vehicle logs any battery thermal fault after this service, do NOT continue driving — return to a Tesla-certified facility, as the HV thermal loop may have been affected.

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