Complete replacement of all hydraulic brake lines on a 2024 Model 3 Performance, including hard lines and flexible hoses at all four corners, followed by a full system bleed. This is a safety-critical hydraulic job requiring careful corrosion-free routing and proper bleeding via Tesla service mode.

Warnings

Tools required

Parts

• Complete brake line set (front and rear hard lines) × 1 — Manufacturer-specified Model 3 Performance hydraulic line kit
• Front flexible brake hose × 2 — Manufacturer-specified Model 3 Performance front brake hose
• Rear flexible brake hose × 2 — Manufacturer-specified Model 3 Performance rear brake hose
• Copper sealing washers (banjo fittings, if equipped) × 8 — OEM specification
• Brake line retaining clips × 10 — OEM specification — replace any damaged on removal

Fluids

• DOT 4 Brake Fluid (Tesla specification — note: vehicle architecture calls for DOT 4 per Tesla, not DOT 3) — 2 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. On 2024 Model 3 Performance the low-voltage battery is typically located behind the right rear seat back panel; some 2024 builds use a lithium 12V under the floor — verify 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. Place vehicle in Transport / Jack Mode via the touchscreen before lifting (suspension and ABS calibration baseline).
7. Chock wheels that remain on the ground when working one corner at a time, or fully lift on a four-post lift for a complete-set replacement.
8. Loosen wheel lug nuts before lifting. Lift only at Tesla-approved jack points using rubber pucks to avoid damaging the aluminum-hybrid floor structure.
9. Have a brake fluid catch pan and absorbent pads positioned under each fitting before opening any line.
10. Confirm you have Tesla service mode access on the touchscreen (required for the booster/ABS bleed routine).

Procedure

1. 1

   Remove all four wheels
   With the vehicle securely supported on jack stands or a lift, remove all four wheels and set aside. Inspect each caliper, hose, and hard line entry point for corrosion or damage before disassembly.
2. 2

   Document existing line routing
   Photograph the routing of every brake line — along the floor pan, through frame channels, near the rear subframe, and at each caliper. Note every retaining clip, grommet, and heat shield location. Replacement lines must follow the identical path to avoid contact with suspension, exhaust-equivalent components, or HV cable trays.
   ⚠️Identify the routing of any nearby orange HV cabling. Replacement lines must NOT contact or be re-routed near HV cabling.
3. 3

   Cap the master cylinder reservoir / minimize fluid loss
   Use a turkey baster or syringe to draw down the brake fluid reservoir to a low level (do not run dry). Place a sealed cap or shop-grade plug to limit air ingress and weeping during line removal.
4. 4

   Disconnect flexible hoses at each caliper
   At each corner, place a catch pan beneath the caliper. Using a line wrench, loosen and disconnect the flexible hose from the caliper inlet (or banjo bolt, depending on caliper style). Allow fluid to drain into the pan. Plug the caliper port immediately to prevent contamination.
   ⚠Performance front calipers are larger (Brembo-style on Model 3 Performance). Support the caliper while disconnecting; do not let it hang by the hose.
   Torque spec

   Line Fittings20 Nm (15 lb-ft)
5. 5

   Disconnect flexible hoses at the chassis-side hard line junctions
   Locate each flexible-to-hard-line junction at the strut/knuckle area (front) and rear subframe area (rear). Hold the hose hex with one wrench while loosening the hard line nut with a flare nut wrench. Remove the retaining clip and separate. Repeat at all four corners.
   ⚠Use line/flare wrenches — open-end wrenches will round these soft fittings.
   Torque spec

   Line Fittings20 Nm (15 lb-ft)
6. 6

   Release hard lines from chassis retaining clips
   Working systematically front-to-rear, release each hard line from its plastic and metal retaining clips along the floor pan and inside frame channels. Note any clip that breaks during removal — these must be replaced. Avoid bending the old lines until they are fully free, to keep routing reference intact.
7. 7

   Disconnect hard lines at the brake booster / ABS modulator
   At the brake booster and ABS hydraulic control unit (front of the vehicle, beneath the frunk area), use a flare nut wrench to disconnect each hard line fitting. Label each port with masking tape so replacement lines reconnect to the correct circuit. Catch all dripping fluid.
   ⚠️The ABS/booster area is in proximity to low-voltage harnesses and may be near HV cable runs depending on build. Identify and avoid any orange cable. STOP if uncertain.
   ⚠Do not rotate the ABS modulator body or stress its mounting — internal valves are sensitive.
   Torque spec

   Line Fittings20 Nm (15 lb-ft)
8. 8

   Remove the old line set from the vehicle
   With both ends free and all clips released, carefully extract the hard line assembly from the vehicle. Lay it on a clean surface alongside the replacement set and verify that lengths, bends, and fitting types match exactly. Do NOT install a set that does not match the original geometry.
9. 9

   Install new hard lines following the documented routing
   Route each new hard line through the same path as the original. Start fittings by hand at both ends to avoid cross-threading, then secure into chassis clips as you go. Leave fittings finger-tight until the entire run is supported in its clips, then final-tighten with a line wrench.
   ⚠Maintain minimum clearance from suspension travel zones, the rear subframe, and any HV cable tray. A pinched line under suspension articulation will fail catastrophically.
   Torque spec

   Line Fittings20 Nm (15 lb-ft)
10. 10

    Install new flexible hoses at all four corners
    Install each new flexible hose at the chassis-side hard line junction (with new retaining clip) and at the caliper. Use new copper sealing washers if the caliper uses banjo fittings. Ensure the hose is not twisted at full lock or full suspension droop — turn the steering lock-to-lock and visually confirm no contact or twist.
    Torque spec

    Line Fittings20 Nm (15 lb-ft)
11. 11

    Verify all fittings, clips, and routing
    Walk the entire system from master cylinder to each caliper. Confirm every fitting is torqued, every retaining clip is seated, and there is no contact between brake lines and suspension, body, or harnesses. Confirm zero contact with any orange HV cabling.
12. 12

    Fill reservoir and perform initial gravity bleed
    Fill the master cylinder reservoir with fresh DOT 4 brake fluid. Open each caliper bleeder in turn (typically furthest-from-master first: RR, LR, RF, LF — verify sequence with the Tesla Service Manual) and allow gravity bleeding until clear, bubble-free fluid appears. Keep the reservoir topped off continuously — do not let it run dry.
    ⚠Bleed sequence on Model 3 should be confirmed against the Tesla Service Manual. Incorrect sequence can leave air trapped in the ABS/booster.
    Torque spec

    Bleeder Screw10 Nm (7 lb-ft)
13. 13

    Pressure bleed each caliper
    Connect a pressure or vacuum bleeder to the reservoir per its instructions (typical pressure: 15-20 psi or per manufacturer of bleeder). Bleed each corner in the manufacturer-specified sequence until clean, air-free fluid flows. Torque each bleeder to spec on closing.
    ⚠Do not overtighten bleeder screws — they are easy to snap off in the caliper body.
    Torque spec

    Bleeder Screw10 Nm (7 lb-ft)
14. 14

    Reconnect 12V and run Tesla service mode brake bleed routine
    Reconnect the low-voltage battery. Power up the vehicle, enter Service Mode on the touchscreen, and run the brake bleed / iBooster bleed routine. This cycles the booster and ABS solenoids to purge air from circuits unreachable by manual bleeding. Re-bleed each caliper after the routine completes. Top off reservoir to MAX.
    ⚠Skipping the service-mode bleed will leave air in the booster and ABS — pedal feel will be soft and emergency braking performance will be compromised.
    Torque spec

    Bleeder Screw10 Nm (7 lb-ft)
15. 15

    Reinstall wheels and lower vehicle
    Reinstall each wheel. Snug lug nuts in a star pattern, lower the vehicle to the ground, then final-torque in a star pattern.
    Torque spec

    Wheel Lug Nuts140 Nm (103 lb-ft)

Reassembly

1. Confirm reservoir is at MAX with fresh DOT 4 fluid and cap is fully seated.
2. Reinstall any underbody panels or splash shields removed for line access, using OEM fasteners.
3. Clean any spilled brake fluid from painted or aluminum surfaces with water and a clean rag.
4. Exit Service Mode on the touchscreen and clear any related fault codes.
5. Verify no warning indicators (ABS, brake, traction control) are illuminated on the instrument cluster.

Verification

• With vehicle stationary and powered on, press the brake pedal firmly several times. Pedal must be firm and high — no sponginess and no progressive sink.
• Hold pressure on the pedal for 30 seconds; pedal must not creep downward (indicates a leak or master cylinder bypass).
• Inspect every fitting (8 caliper-end + chassis-side junctions + ABS/booster ports) under pedal pressure for any weeping fluid. Repeat after a short drive.
• Drive at low speed in a safe area and perform progressively harder stops. Confirm straight, even braking with no pull and no ABS activation on dry pavement.
• Confirm regenerative braking and friction braking blend smoothly — abnormal blending behavior may indicate residual air in the booster circuit; repeat the service-mode bleed if so.
• Re-inspect all fittings 24 hours and ~100 miles after the repair for any seepage.
• Note in service records: Tesla recommends brake fluid replacement every 2 years regardless of mileage — log this service date as the new baseline.

More procedures for this vehicle