Pressure test the cooling system on the 2024 Tesla Roadster Tri Motor to identify leaks in the coolant circuit. Note that this Roadster uses a unique architecture with multiple motor cooling loops; this procedure covers only the accessible low-voltage coolant circuit and excludes any HV battery thermal loop work.

Warnings

Tools required

Parts

• Replacement coolant reservoir cap (if cap fails pressure test) × 1 — OEM Tesla Roadster coolant cap — specification per service manual

Fluids

• Tesla Battery/Motor Coolant (G-48) — for top-off only if needed — 0.5 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 12V (or 16V/48V on applicable models) low-voltage battery. See architecture notes above for location.
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 — verify coolant temperature is ambient before proceeding.
7. Identify the correct coolant reservoir for the non-HV cooling loop. The Roadster has multiple loops; do not test any line connected to the HV battery thermal management system.
8. Stage absorbent pads beneath the reservoir to catch any drips when removing the cap.
9. Visually inspect all accessible hoses, clamps, radiator end tanks, water pump weep holes, and reservoir seams for staining, crust, or wet spots before testing.

Procedure

1. 1

   Verify system is cool and depressurized
   Confirm the coolant is at ambient temperature. Slowly rotate the reservoir cap to its first detent to vent any residual pressure, listening for hissing. Once fully vented, remove the cap.
   ⚠️If hissing continues for more than a few seconds or coolant bubbles up, the system is still hot — re-seat the cap and wait longer.
2. 2

   Check coolant level and condition
   Verify coolant is at the correct cold-fill level in the reservoir. Inspect color and clarity — Tesla G-48 coolant should appear clean. Contaminated, oily, or rusty coolant indicates a deeper problem; document before pressurizing.
3. 3

   Install pressure tester adapter
   Select the pressure tester adapter that matches the reservoir neck. Thread or seat the adapter onto the reservoir per the tester manufacturer's instructions, ensuring the seal is fully engaged. Do not force-fit an incorrect adapter.
   ⚠A poorly seated adapter will leak and produce a false positive — verify seal integrity before pumping.
4. 4

   Connect pressure tester pump and gauge
   Connect the hand pump and gauge assembly to the adapter. Confirm the gauge reads zero before pressurizing.
5. 5

   Pressurize to the system's rated cap pressure
   Locate the pressure rating stamped on the OEM coolant cap. Pump the tester slowly until the gauge reaches that exact rated pressure — do not exceed it. If the rating is not legible, refer to the Tesla Service Manual for the specified test pressure rather than guessing.
   ⚠Exceeding rated pressure may damage the reservoir, hoses, or radiator.
6. 6

   Hold and observe gauge
   Hold pressure for a minimum of 15 minutes. The gauge should hold steady. A slow drop indicates a leak; a rapid drop indicates a significant leak or failed component.
7. 7

   Locate leaks if pressure drops
   While the system is pressurized, inspect with a flashlight or borescope: all hose connections and clamps, radiator end tanks and core, water pump housing and weep hole, reservoir seams and cap interface, heater core lines (if accessible), and any visible coolant fittings on the motor cooling loop. Look for fresh wet spots or seeping coolant. Do NOT inspect or trace lines into the HV battery pack area.
   ⚠️If a leak appears to originate from a component connected to the HV battery thermal loop, STOP and refer the job to a Tesla-certified technician.
8. 8

   Test the coolant cap separately
   Using the appropriate cap adapter on the pressure tester, pressurize the reservoir cap to its rated pressure. The cap must hold pressure and release at or near the rated value. Replace the cap if it fails to hold or fails to release at the correct pressure.
9. 9

   Release pressure
   Use the bleed valve on the pressure tester to slowly release system pressure to zero before disconnecting any fittings.
   ⚠Never disconnect the tester while pressurized — coolant will spray.
10. 10

    Remove tester and reinstall cap
    Remove the adapter from the reservoir. Inspect the reservoir neck sealing surface for damage. Reinstall the OEM cap (or a new one if the cap failed testing) and tighten to the click/detent specified by the cap design.

Reassembly

1. Top off coolant with Tesla Battery/Motor Coolant (G-48) only if level dropped during testing — do not mix coolant types.
2. Wipe down the reservoir and any areas where coolant may have dripped.
3. Reconnect the low-voltage battery.
4. Close hood/frunk and any service panels removed for access.

Verification

• With the vehicle powered on, confirm no coolant-related warnings appear on the center display.
• Allow the vehicle to reach normal operating temperature, then re-inspect all areas previously identified as suspect for any new weeping or staining.
• After a short drive, recheck coolant level in the reservoir when cool — level should remain stable.
• Per Tesla's current guidance, battery/motor coolant is no longer considered strictly 'lifetime' — inspect at 4 years / 50,000 miles. Log this pressure test date for future reference.
• If any leak was found and not repaired during this visit, do not return the vehicle to service until the source is addressed.

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