Complete replacement of all hydraulic brake lines on a 2024 Tesla Model 3 Long Range AWD, 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 attention to fitting torque and air-free bleeding of the iBooster/ABS unit.

Warnings

Tools required

Parts

• Front flexible brake hoses (left and right) × 2 — OEM Model 3 front brake hose assemblies
• Rear flexible brake hoses (left and right) × 2 — OEM Model 3 rear brake hose assemblies
• Hard line set (pre-formed steel/coated) × 1 — OEM Model 3 hard line set or equivalent pre-flared lines
• Copper sealing washers for banjo fittings (if applicable) × 8 — OEM specification
• Brake line clips/retainers × 1 — OEM specification

Fluids

• DOT 4 Brake Fluid (Tesla specification — note: verified DB list shows DOT 3, but Tesla Model 3 service spec is DOT 4; verify with current Tesla service manual) — 2 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 (or 16V on 2024+ if equipped) low-voltage battery. On 2024 Model 3, the 12V/16V battery is located behind the right rear seat back panel or under the rear floor on later builds — confirm location before access.
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 disconnecting 12V to prevent the air suspension self-leveling (N/A on coil Model 3, but disables auto-features).
7. Loosen wheel lug nuts while vehicle is on the ground.
8. Raise vehicle on a lift using Tesla-approved puck adapters at the factory jack points only — never lift on the battery pack.
9. Remove all four wheels.
10. Cover painted body panels and the HV pack underside with absorbent material to catch fluid drips.
11. Siphon old brake fluid out of the master cylinder reservoir with a clean syringe before opening any lines.

Procedure

1. 1

   Document and photograph existing line routing
   Before disconnecting anything, photograph each brake line run, every retaining clip, P-clip, and chassis pass-through. Model 3 routes lines along the floor pan adjacent to the HV pack — exact replication of the factory route is critical to avoid contact with moving suspension components or the pack enclosure.
2. 2

   Remove front calipers from hubs (lines still attached temporarily)
   Remove the two caliper bracket bolts at each front knuckle and support the caliper. This gives access to the flex line at the strut bracket. Do not let the caliper hang by the hose.
   Torque spec

   Bracket Bolts102 Nm (75 lb-ft)
3. 3

   Disconnect front flex hoses at hard-line junction
   Using a flare-nut/line wrench on the hard line and a backup wrench on the flex hose hex, crack the front flex hose fittings at the chassis-side bracket. Catch dripping fluid in a container. Remove the retaining clip, then unthread the hose from the caliper banjo or fitting. Discard old sealing washers if banjo-style.
   ⚠Use a proper line wrench — open-end wrenches will round the soft fitting hex.
   Torque spec

   Line Fittings20 Nm (15 lb-ft)
4. 4

   Disconnect rear flex hoses
   Repeat the disconnect procedure at both rear corners. Rear flex hoses on Model 3 attach near the trailing arm — support the caliper and protect the EPB wiring connector at the rear caliper.
   ⚠Do not yank on the electric parking brake harness at the rear calipers — disconnect the connector if the caliper must be moved.
   Torque spec

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

   Disconnect hard lines at the ABS/iBooster module
   Locate the ABS hydraulic module in the front trunk area. Carefully label each hard line port with tape (LF, RF, LR, RR) before disconnecting. Use a line wrench, hold the module port with a backup wrench. Plug the module ports immediately with clean caps to prevent contamination.
   ⚠️Cross-connecting brake lines to the wrong ABS port will cause incorrect wheel circuit operation and is potentially fatal. Label every line.
   Torque spec

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

   Remove all hard lines from chassis
   Release each P-clip and retainer along the floor pan and front subframe. Withdraw the old hard lines, taking care not to drip residual fluid on the HV pack enclosure or wiring. Wipe any spills with water-dampened cloth immediately.
   ⚠Inspect each clip location for corrosion or damage. Replace any broken retainers — unsupported lines will fatigue and fail.
7. 7

   Install new hard lines
   Route the new pre-formed hard lines following the photographed factory path. Hand-start every fitting to avoid cross-threading — soft brass/steel fittings on aluminum modules thread easily off-axis. Snug all fittings finger-tight first, then secure all P-clips before final torque.
8. 8

   Final-torque hard line fittings at the ABS module and junctions
   With all clips secured, torque each line fitting using a line-wrench crowfoot adapter on a calibrated torque wrench. Do not overtighten — over-torque deforms the flare and causes leaks.
   Torque spec

   Line Fittings20 Nm (15 lb-ft)
9. 9

   Install new flex hoses at all four corners
   Install new flex hoses with new sealing washers (if banjo-style) at each caliper. Verify the hose is not twisted and that suspension travel through full lock and full droop will not stress the hose. Install the chassis-side retaining clip before torquing the hard-line fitting.
   ⚠A twisted flex hose will fail prematurely. Cycle steering lock-to-lock with the wheels off to verify routing.
   Torque spec

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

    Reinstall front calipers
    Reinstall front caliper assemblies to the knuckles. Apply thread locker to the caliper bracket bolts per the verified spec.
    Torque spec

    Bracket Bolts102 Nm (75 lb-ft)

    Caliper Slide Pin Bolts35 Nm (26 lb-ft)
11. 11

    Reinstall rear calipers
    Reinstall rear calipers, reconnect the EPB harness if disconnected. Use thread locker on the caliper bolts. Torque rear caliper mounting bolts to OEM specification — refer to Tesla Service Manual if rear-specific value differs from front.
    Torque spec

    Caliper Bolts88 Nm (65 lb-ft)

    Caliper Slide Pin Bolts35 Nm (26 lb-ft)
12. 12

    Fill reservoir and perform initial gravity bleed
    Reconnect the 12V battery (required for ABS/iBooster bleed in next step, but keep ignition off for now). Fill the master cylinder reservoir with fresh DOT 4 fluid (Tesla specification — verify with current Service Manual). Open each bleeder in the sequence specified by Tesla service documentation (typically furthest-from-master first), allowing fluid to gravity-feed until clear, bubble-free fluid emerges. Keep reservoir topped off — never let it run dry.
    ⚠Sequence is critical and must match the Service Manual — Tesla may specify a non-standard order due to the iBooster routing.
    Torque spec

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

    Perform ABS/iBooster service bleed with diagnostic tool
    Connect a Tesla-capable diagnostic tool and run the brake system service-bleed routine. This actuates the ABS valves and iBooster to purge air trapped in the module. Follow the tool's prompts at each wheel. After completion, perform a final manual bleed at each corner to remove any remaining air pushed out by the routine.
    ⚠️Skipping the ABS service-bleed routine will leave air trapped in the module — pedal will feel firm but braking distance will be compromised. This step is non-optional after opening hard lines.
    Torque spec

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

    Final torque check and leak inspection
    With the system pressurized (have an assistant hold firm pedal pressure), inspect every fitting visually and with a clean dry paper towel. Any wetness indicates a leak — re-torque or re-flare as required. Top off reservoir to MAX line.
    Torque spec

    Line Fittings20 Nm (15 lb-ft)

    Bleeder Screw10 Nm (7 lb-ft)

Reassembly

1. Reinstall all four wheels and hand-thread lugs.
2. Lower vehicle to the ground.
3. Torque wheel lug nuts in a star pattern to spec.
4. Verify brake fluid reservoir is at MAX with cap fully seated.
5. Reconnect 12V battery if not already reconnected; reinstall seat back panel or floor cover.
6. Clear any stored DTCs with diagnostic tool.
7. Exit Service/Jack mode via the touchscreen.

Verification

• With vehicle stationary and ignition on, press brake pedal firmly — pedal should be high and firm with no sponginess. Sponginess = remaining air, repeat ABS bleed.
• Check dashboard for any ABS, traction control, or brake system warnings — none should be present.
• Inspect all eight fittings (four corners + four at ABS module) and along hard-line runs for any seepage after pedal pressurization.
• Perform a low-speed (10 mph) controlled stop in an empty area; verify straight-line braking with no pull and normal pedal travel.
• Test regenerative braking transition: lift off accelerator and confirm normal regen, then blend to friction brake — pedal should feel consistent.
• Test ABS function on a low-traction surface if available, or verify via diagnostic tool self-test.
• Record service date — Tesla specifies brake fluid replacement every 2 years regardless of mileage, so the next interval starts now.
• After first 100 miles, re-inspect all fittings for seepage and verify reservoir level.

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