Battery cooling system service on a 2024 Model S Plaid involves draining and refilling the low-voltage/coolant loops accessible without breaching the HV battery thermal system. This procedure covers coolant replacement and inspection of accessible cooling components only — the HV pack thermal loop, octovalve, superbottle, and heat pump are off-limits without Tesla Toolbox.

Warnings

Tools required

Parts

• Tesla-spec coolant (G-48 / Pentosin G13 equivalent) × 1 — Tesla-approved battery/motor coolant — do not substitute
• Coolant hose clamps (as needed if disturbed) × 4 — OEM replacement clamps if single-use type encountered
• Underbody fastener clips (commonly damaged on removal) × 10 — OEM aero panel clips

Fluids

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

Preparation

1. Park on level ground, place in P, engage parking brake.
2. Exit ALL doors with 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 low-voltage battery. On 2024 Model S Plaid this is typically a 16V lithium unit under the rear seat; some configurations retain a 12V in the frunk under the nose cowl panel. Verify by VIN before service.
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 completely — coolant system can remain pressurized and hot for hours after driving or charging.
7. Place the vehicle in Transport / Jack Mode via the touchscreen BEFORE disconnecting the LV battery, to prevent air suspension from leveling during lift.
8. Raise vehicle on a lift using only Tesla-designated lift points with proper pad adapters — do NOT lift on the battery pack edges or underbody panels.
9. Identify the accessible coolant reservoir(s) in the frunk area. Confirm the service scope is limited to the powertrain/PCS coolant loop, not the HV pack loop.

Procedure

1. 1

   Remove frunk liner and access nose cowl
   Open the frunk and remove the liner and any access panels covering the coolant reservoir and front cooling components. Use plastic trim tools — clips are fragile and commonly break.
2. 2

   Identify accessible coolant loop
   Visually identify the coolant reservoir cap and accessible hoses for the powertrain coolant loop. Trace lines carefully. If any line leads directly into an HV-orange-marked component or into the battery pack thermal interface, STOP — that loop is out of scope for this procedure.
   ⚠️If you cannot positively identify the loop as non-HV, do not proceed. The Plaid's thermal architecture shares plumbing between motor, PCS, and pack circuits via the octovalve.
3. 3

   Remove front underbody aero panels
   Lift the vehicle and remove the front underbody aero shield fasteners to access the lower coolant lines and any drain points. Replace damaged clips on reinstall.
   Torque spec

   Cover Screws11 Nm (8 lb-ft)
4. 4

   Relieve coolant system pressure
   With the system fully cooled, slowly open the coolant reservoir cap to release residual pressure. Cover with a shop towel during release.
   ⚠Hot coolant under pressure can cause severe burns. System must be at ambient temperature before opening.
5. 5

   Drain accessible coolant
   Position the drain pan beneath the lowest accessible point of the powertrain coolant loop. Loosen the lowest hose clamp at a non-HV junction and direct flow into the pan. Capture all drained fluid for proper disposal — Tesla coolant is not standard automotive antifreeze.
   ⚠Do not drain by disconnecting any line that interfaces with the octovalve, superbottle, heat pump, or pack manifold.
   Torque spec

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

   Inspect coolant condition and components
   Examine drained fluid for discoloration, debris, or oil contamination — any of these indicate a deeper failure (e.g., chiller breach) requiring Tesla diagnostic intervention. Inspect accessible hoses for swelling, chafing, or seepage. Inspect reservoir for sediment.
   ℹ️Milky or oily coolant on a Plaid often indicates internal failure of a thermal component — refer to a Tesla service center; do not simply refill.
7. 7

   Reconnect drain point and prepare for fill
   Reattach the drained hose with a new clamp if the original is single-use. Ensure all connections in the disturbed area are clean and properly seated.
   Torque spec

   Coolant Line Fittings15 Nm (11 lb-ft)
8. 8

   Vacuum fill the coolant system
   Attach a vacuum fill tool to the reservoir. Pull and hold a vacuum per the tool manufacturer's specification to verify system integrity — pressure loss indicates a leak. Then draw in fresh Tesla-spec coolant until the system is filled.
   ⚠Do not fill with non-Tesla-approved coolant. Pentosin G13 / G-48 chemistry only.
9. 9

   Top off reservoir and verify level
   Top the reservoir to the manufacturer's MAX line. Install the cap finger-tight, then to the cap's indexed lock position.
10. 10

    Reinstall aero panels and frunk liner
    Reinstall front underbody aero panels with new clips as needed. Reinstall frunk liner and access panels.
    Torque spec

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

    Reconnect low-voltage battery
    Reconnect the LV battery terminals. Clean terminals before reattachment.
    Torque spec

    Battery Terminal Bolts7 Nm (5 lb-ft)

    Ground Cable Bolt14 Nm (10 lb-ft)

Reassembly

1. Verify all hose clamps in the disturbed area are seated and torqued to OEM specification.
2. Confirm all aero panel fasteners are installed — missing fasteners cause panel flutter and loss at highway speed.
3. Lower the vehicle and exit Jack/Transport mode via the touchscreen.
4. Confirm no tools or rags remain in the frunk or under the vehicle.

Verification

• Power the vehicle on and check the touchscreen for any thermal system, coolant, or battery alerts. Any new alert means STOP and diagnose before driving.
• With vehicle running and stationary, monitor for coolant pump audible operation and observe reservoir level — air pockets will cause level drop as the system self-bleeds.
• Take a short, low-load drive (avoid Plaid/Track mode) and recheck coolant level after the system has cooled. Top off if needed.
• Inspect all disturbed connections for seepage after the first drive cycle and again after 24 hours.
• Log the service date and mileage. Per current Tesla guidance, inspect battery/powertrain coolant again at 4 years or 50,000 miles, whichever comes first.
• If any orange cable or HV component was disturbed at any point, DO NOT drive the vehicle — have it inspected by a Tesla-certified technician.

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