Replacement of a single hydraulic brake line on a 2024 Tesla Cybertruck Cyberbeast. The Cybertruck uses a conventional hydraulic brake circuit fed by an electric iBooster (no vacuum), so brake-line service follows traditional hydraulic practice plus a brake bleed afterward.

Warnings

Tools required

Parts

• Replacement brake line (hard line or flexible hose, as applicable to the segment being replaced) × 1 — OEM Tesla Cybertruck brake line for the specific corner/segment being serviced
• Copper sealing washers (if banjo-fitting style at caliper end) × 2 — OEM specification — replace one-time-use sealing washers
• Brake line retaining clip(s) × 1 — OEM specification — frame/subframe retaining clips (replace if deformed)

Fluids

• DOT 3 Brake Fluid (Tesla-spec) — 1 qt

Preparation

1. Park on level ground, place in P, engage the electric parking brake.
2. Exit ALL doors with the key fob carried 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 48V low-voltage battery per Cybertruck service procedure (NOT a 12V battery — the Cybertruck uses a 48V LV architecture; observe the correct disconnect sequence and insulate the terminal).
4. DO NOT touch, cut, or pierce ANY orange cable — these are high-voltage and lethal at 800V on this platform.
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. Identify which brake line segment is being replaced (specific corner, hard line vs. flex hose). Have the correct OEM replacement in hand before opening the system.
7. Place the vehicle in Transport / Jack Mode via the touchscreen so the air suspension does not attempt to self-level once raised.
8. Loosen the relevant wheel lug nuts while the wheel is still on the ground.
9. Raise the vehicle at the Tesla-approved jack points using puck adapters and support on rated jack stands. Confirm stability before going underneath.
10. Remove the wheel at the affected corner.
11. Place a catch pan under the work area and have rags ready — DOT 3 fluid will drip from both ends of the line.

Procedure

1. 1

   Cap the master cylinder reservoir
   Open the front trunk, locate the brake fluid reservoir on the iBooster assembly, and place a sealed cap or plastic film under the reservoir cap to slow fluid loss while the line is open. Verify fluid level is at MAX before starting; top up with fresh DOT 3 if low.
2. 2

   Inspect and photograph the line routing
   Before disturbing anything, photograph the entire run of the brake line being replaced — every retaining clip, bracket, grommet, and the orientation of each end fitting. The replacement must follow the exact same path to avoid chafing against suspension or driveline components.
3. 3

   Loosen the upper (hard line) fitting first
   Using a flare-nut wrench of the correct size, break loose the fitting at the upper/inboard end of the line (typically where the flex hose meets a hard line on a chassis bracket). Loosen only — do not fully remove yet. This confirms the fitting will release without rounding before you commit.
   ⚠Always use a flare-nut wrench on hydraulic fittings. An open-end wrench will round the soft hex and turn a 1-hour job into a multi-hour repair.
4. 4

   Disconnect the lower (caliper or junction) end
   At the caliper end, remove the bolt or fitting securing the line. If the line uses a banjo bolt, remove the banjo bolt and discard the two copper sealing washers — these are one-time-use. If it is a threaded flare fitting, back it out with a flare-nut wrench. Allow fluid to drain into the catch pan.
5. 5

   Release intermediate retaining clips and brackets
   Working along the line's run, release each retaining clip from its frame/subframe bracket. Clips that deform on removal must be replaced. Note the order and orientation of each clip so the new line sits in the same plane.
6. 6

   Fully remove the upper fitting and extract the old line
   Finish unthreading the upper fitting, plug the open hard-line port immediately with a clean plastic cap or shop towel to keep contamination and air out, and remove the old line from the vehicle.
7. 7

   Compare old and new lines
   Lay the new line next to the old one. Confirm length, bend pattern, end-fitting types, and any integrated brackets match. Mismatched aftermarket lines are the most common cause of post-repair leaks and chafing failures.
8. 8

   Install the new line — start both ends finger-tight
   Route the new line along the photographed path. Start the upper fitting by hand several turns, then start the lower fitting by hand several turns. Cross-threading a brake fitting ruins the mating component — never start a fitting with a wrench.
   ⚠If a fitting will not turn easily by hand for at least 2-3 full turns, back it out and re-start. Cross-threaded brake fittings will leak under pressure.
9. 9

   Seat intermediate retaining clips
   Snap the line into each chassis retaining clip along the run. Verify the line is not contorted, twisted, or contacting any suspension, halfshaft, or stainless underbody panel through its full range of suspension travel.
10. 10

    Tighten the line fittings
    Tighten both the upper and lower hydraulic fittings to OEM specification using a flare-nut crowfoot on a torque wrench where possible. Torque to OEM specification — refer to Tesla Service Manual for the exact value for this fitting size. Do not overtighten — flare fittings seal by deformation of the flare, not by clamping force.
11. 11

    Install new copper sealing washers (banjo-style only)
    If the caliper end is a banjo fitting, install NEW copper sealing washers on both sides of the banjo eye and torque the banjo bolt to OEM specification — refer to Tesla Service Manual. Reusing old copper washers will cause a slow leak.
12. 12

    Bleed the affected brake circuit
    Top off the reservoir with fresh DOT 3. Attach a bleeder bottle to the caliper bleeder screw at the affected corner. Open the bleeder, gravity-bleed until clean fluid flows without bubbles, then perform a pressure or two-person pedal bleed until firm. Close the bleeder and torque it.
    ⚠The Cybertruck's iBooster may require a scan-tool-initiated bleed routine to fully purge the boost circuit. If pedal feel is not firm after a manual bleed, an automated bleed cycle is required.
    Torque spec

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

    Top off and verify reservoir level
    With the bleed complete, bring the reservoir up to the MAX line with fresh DOT 3. Re-cap the reservoir and wipe down any spilled fluid with water immediately to protect paint and stainless surfaces.
14. 14

    Pressure-check for leaks before reinstalling the wheel
    With the wheel still off, have an assistant press the brake pedal firmly and hold for 30 seconds while you inspect both fittings, all clips, and the full line run for any weeping fluid. Repeat 3-4 times. No drops, no damp spots — period.

Reassembly

1. Reinstall the wheel and hand-thread all lug nuts.
2. Lower the vehicle until the tire just contacts the ground.
3. Torque the lug nuts in a star pattern in two passes (50% then 100%) to the verified Wheel Lug Nut spec.
4. Fully lower the vehicle and remove jack stands.
5. Reconnect the 48V low-voltage battery and secure the terminal cover.
6. Exit Jack Mode via the touchscreen and allow the air suspension to re-level.

Verification

• With the vehicle still stationary and powered on, press the brake pedal firmly several times. Pedal must be firm and high — a soft or sinking pedal indicates remaining air or a leak. Do not drive until pedal is firm.
• Visually re-inspect both fittings and the full line route for any sign of weeping fluid after the first pedal applications.
• Check the touchscreen for any brake-system, ABS, traction-control, or iBooster fault messages. Clear with a scan tool if present and confirm they do not return.
• Perform a low-speed brake test in a safe, empty area: 5 mph stops first, then 15 mph, then 30 mph, confirming straight-line stops and no pulsation, pull, or warning lamps.
• Re-check the reservoir level and re-inspect for leaks after the first short test drive.
• Tesla recommends full brake fluid replacement every 2 years regardless of mileage — log this service date and consider a complete flush at the next interval if not performed today.

More procedures for this vehicle