Replacement of accessible low-voltage EV coolant lines on a 2024 Model 3 Long Range AWD. This procedure covers non-HV coolant hoses only — any work involving the battery thermal loop, octovalve, or superbottle internals must be performed by a Tesla-certified technician.

Warnings

Tools required

Parts

• Replacement coolant line/hose (manufacturer-specified for affected circuit) × 1 — Tesla OEM coolant line — match by VIN at parts counter
• Hose clamps (if single-use crimp style) × 4 — OEM-spec replacement clamps
• O-rings / quick-connect seals (if equipped on affected fittings) × 1 — OEM-spec seal kit for the line being replaced

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 is typically lithium and located under the floor area or behind the right rear seat panel — verify location for your specific build before disconnecting.
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 sit at least 30 minutes after last drive so coolant temperature drops to ambient.
7. Place vehicle in Transport/Tow mode procedure is NOT required for this job, but ensure HV contactors have opened (confirmed by 2-minute wait after 12V disconnect).
8. Raise vehicle on a lift using Tesla-approved lift pad locations to avoid rocker panel damage.
9. Position a coolant catch pan under the work area before opening any fitting.
10. Identify the specific coolant line(s) to be replaced and confirm they are NOT part of the HV battery loop, octovalve, or heat pump assembly. If they are — STOP.

Procedure

1. 1

   Remove access panels
   Remove the front underbody aero shield and any relevant frunk liner or wheel-well liner needed to access the coolant line route. Use a plastic trim tool to release clips, and remove fasteners with the appropriate driver. Set fasteners aside in order — Model 3 uses a mix of plastic clips and metric bolts that are not interchangeable.
   Torque spec

   Cover Screws11 Nm (8 lb-ft)
2. 2

   Locate and confirm the affected coolant line
   Trace the coolant line to be replaced from end to end. Confirm both endpoints are on accessible, non-HV components (e.g., radiator, coolant pump housing, reservoir). If either endpoint connects to the octovalve, superbottle, heat pump, drive unit thermal port, or HV battery — STOP. That portion of the system is dealer-only.
   ⚠️If the line connects to an HV thermal component, abort the procedure.
3. 3

   Drain the coolant circuit
   Position the catch pan beneath the lowest point of the affected circuit. Open the coolant reservoir cap slowly to relieve pressure. Loosen the lowest hose clamp on the affected line to begin drainage. Allow the circuit to drain fully — expect up to ~10 qt depending on which loop is affected. Capture all fluid; Tesla coolant must be disposed of per local hazardous waste regulations.
   ⚠Coolant is hot if vehicle was recently driven. Wait for full cool-down.
   Torque spec

   Hose Clamps3 Nm (2 lb-ft)
4. 4

   Disconnect sensors and connectors near the line
   If the coolant line routes near or through any sensors (e.g., coolant temperature sensor) or has electrical connectors clipped to brackets along its length, disconnect them now. Photograph routing and clip locations for reassembly reference.
   Torque spec

   Connector Bolts7 Nm (5 lb-ft)

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

   Release line retaining brackets
   Remove any brackets or P-clamps securing the coolant line to the chassis or subframe. Keep hardware organized by location — bracket bolt sizes vary along the line route.
   Torque spec

   Bracket Bolts20 Nm (15 lb-ft)
6. 6

   Disconnect the coolant line fittings
   Depending on the line, fittings will be either spring-band/worm-gear hose clamps over barbed fittings, or quick-connect couplers with locking clips. For quick-connects, depress the locking tabs and pull straight off — do not pry sideways or you will damage the fitting. For clamped joints, loosen clamps and twist the hose gently to break the seal. Capture residual coolant in the catch pan.
   ⚠Quick-connect fittings are fragile. Replace any seal/O-ring that comes off with the old line.
   Torque spec

   Coolant Line Fittings15 Nm (11 lb-ft)

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

   Remove the old coolant line
   Carefully extract the old line from its routing path. Note any heat shielding, foam wrap, or routing clips so they can be transferred or replaced. Inspect the removed line for the failure mode (cracking, swelling, abrasion) and check the routing path for the cause (chafe point, heat source).
8. 8

   Install the new coolant line
   Route the new line exactly as the original. Transfer any heat shielding or foam wrap as needed. Seat the line fully into each fitting. For quick-connects, push until you hear/feel the locking tab engage and verify by gently pulling back — it should not separate. For clamped joints, position clamps in their original locations (away from the bend radius).
   ⚠A misrouted line will chafe against moving suspension or hot components and fail prematurely.
9. 9

   Tighten fittings and clamps to spec
   Torque coolant line fittings to 15.0 Nm (11.0 lb-ft). Torque hose clamps to 3.0 Nm (2.0 lb-ft) — these are low-torque; over-tightening will cut the hose. Reinstall any retaining brackets and torque to 20.0 Nm (15.0 lb-ft).
   Torque spec

   Coolant Line Fittings15 Nm (11 lb-ft)

   Hose Clamps3 Nm (2 lb-ft)

   Bracket Bolts20 Nm (15 lb-ft)
10. 10

    Reconnect sensors and connectors
    Reattach any electrical connectors disconnected in step 4. Torque sensor bolts to 11.0 Nm (8.0 lb-ft) and connector bolts to 7.0 Nm (5.0 lb-ft). Verify all clips are fully seated.
    Torque spec

    Sensor Bolts11 Nm (8 lb-ft)

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

    Vacuum-fill the coolant system
    Tesla cooling circuits MUST be vacuum-filled — gravity fill will leave air pockets that cause pump cavitation and overheating. Connect a vacuum fill tool to the reservoir, pull the system down to at least -25 inHg, hold for 5 minutes to verify no leaks (vacuum should not decay), then draw in fresh Tesla-spec G-48 coolant. Refill to the MAX line on the reservoir.
    ⚠Do not skip vacuum fill. Air in the loop will cause pump damage and thermal faults.
    ⚠️Use only Tesla-spec G-48 coolant. Other coolants will corrode the aluminum circuits.
12. 12

    Reinstall access panels
    Reinstall the underbody aero shield, wheel-well liners, and any other panels removed for access. Torque mounting bolts to 27.0 Nm (20.0 lb-ft) where applicable; torque cover screws to 11.0 Nm (8.0 lb-ft). Ensure all clips are seated — a loose aero shield will tear off at highway speed.
    Torque spec

    Mounting Bolts27 Nm (20 lb-ft)

    Cover Screws11 Nm (8 lb-ft)

Reassembly

1. Lower the vehicle to the ground.
2. Reconnect the 12V low-voltage battery.
3. Close the frunk and any opened access points.
4. Allow the vehicle to wake up fully (touchscreen on, systems initialized) before starting the verification drive.

Verification

• Power on the vehicle and check the touchscreen for any thermal or coolant-related alerts. Common alert codes will reference the cooling circuit if air remains.
• With the vehicle on, run the climate system on max heat, then max A/C for 5 minutes each — this cycles the coolant pumps and helps purge residual air.
• Visually inspect every fitting and clamp you touched for weeping or drips. Any moisture = redo that joint.
• Check coolant reservoir level after the system has cycled; top up to MAX if needed with Tesla-spec G-48.
• Take a 10-15 minute test drive including some sustained acceleration. Recheck reservoir level and inspect for leaks once cooled.
• Document the service date and mileage. Tesla recommends battery coolant inspection at 4 years / 50,000 miles — note this for the next interval.
• If any thermal warning appears on the touchscreen during or after the drive, stop driving and have the system diagnosed by a Tesla-certified technician — Toolbox software may be required to clear faults or rebalance the thermal system.

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