Replacement of a rear flexible brake hose on a 2024 Model 3 Performance AWD. The hose connects the hard line at the body/subframe to the rear caliper; replacement requires brake fluid bleeding afterward.

Warnings

Tools required

Parts

• Rear brake hose assembly (left or right as applicable) × 1 — Tesla Model 3 Performance rear flexible brake hose — order by VIN
• Banjo bolt copper sealing washers × 2 — New copper crush washers sized for OEM banjo bolt
• Hose bracket retaining clip (if damaged on removal) × 1 — Manufacturer-specified retaining clip

Fluids

• DOT 4 Brake Fluid (Tesla specification — do NOT use DOT 3 despite generic database entry) — 1 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 low-voltage battery. On 2024 Model 3 this is typically a Li-ion unit; access varies by build — refer to architecture notes and the Tesla service manual for the correct location and disconnect sequence.
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. Disable Auto Hold and Creep in the touchscreen prior to disconnecting 12V if possible.
7. Loosen rear lug nuts while the wheel is on the ground.
8. Lift the rear of the vehicle ONLY at Tesla-approved jack points using puck adapters, support on jack stands, and confirm stability.
9. Remove the rear wheel on the side being serviced.
10. Place a drip pan under the caliper and have brake line plugs ready to minimize fluid loss and contamination.

Procedure

1. 1

   Inspect and identify hose routing
   Trace the rear flexible hose from the hard line union at the body/subframe bracket down to the banjo fitting at the rear caliper. Note the routing, the bracket clip location, and any zip ties or wire-loom standoffs so the new hose can be installed identically without contact with suspension or driveshaft components.
2. 2

   Pre-loosen the hard line fitting
   Using a flare-nut (line) wrench, slightly break loose the hard line fitting at the upper end of the flexible hose where it meets the chassis hard line. Do not unthread yet — this confirms the fitting will move without rounding. Hold the hose hex with a backup wrench to prevent twisting the rubber.
   ⚠Use a flare-nut wrench only. An open-end wrench will round the soft fitting.
   Torque spec

   Line Fittings20 Nm (15 lb-ft)
3. 3

   Remove the banjo bolt at the caliper
   Place a drip pan under the caliper. Remove the banjo bolt securing the hose to the rear caliper inlet. Discard the two copper sealing washers — they must be replaced. Cap or plug the caliper port immediately to limit fluid loss and contamination.
   Torque spec

   Brake Hose Banjo Bolt25 Nm (18 lb-ft)
4. 4

   Release the hose from its support bracket
   Remove the retaining clip securing the flexible hose to the chassis bracket. If the clip is bent or corroded, replace it. Do not pry against painted aluminum suspension components.
   Torque spec

   Brake Hose Bracket10 Nm (7 lb-ft)
5. 5

   Disconnect the hard line and remove the hose
   Fully unscrew the hard line fitting from the top of the flexible hose using the line wrench with backup wrench on the hose hex. Cap the hard line. Remove the flexible hose assembly from the vehicle.
   ⚠Do not allow the hard line to flex or kink. Even small bends in the steel line can cause future cracks.
   Torque spec

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

   Compare old and new hoses
   Lay the new hose next to the old one and verify identical length, end fittings, bracket index tab orientation, and any anti-rotation features. Confirm caliper-end and chassis-end orientation before installation.
7. 7

   Install upper (hard line) end first
   Position the new hose into its chassis bracket and start the hard line fitting by hand to avoid cross-threading. Once hand-tight, snug with a line wrench while holding the hose hex with a backup wrench. Then torque to the manufacturer-specified value.
   Torque spec

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

   Secure the hose in its chassis bracket
   Seat the hose's index tab fully into the chassis bracket and install a new retaining clip if needed. Confirm the hose is not twisted along its length. Torque any bracket fastener to specification.
   Torque spec

   Brake Hose Bracket10 Nm (7 lb-ft)
9. 9

   Install banjo bolt at caliper with NEW copper washers
   Place a new copper washer on each side of the banjo fitting (one between bolt head and fitting, one between fitting and caliper). Thread the banjo bolt by hand, verify the hose orientation does not contact the wheel, tire, or suspension at any point through full travel, then torque to specification.
   ⚠Reusing copper washers will cause a slow leak. Always replace both.
   Torque spec

   Brake Hose Banjo Bolt25 Nm (18 lb-ft)
10. 10

    Verify routing through suspension cycle
    With the caliper still free to move, cycle the suspension by hand and steering through full range (where applicable on a rear hose, articulate the caliper/knuckle as designed) to confirm the hose does not contact the tire, wheel liner, driveshaft, or sway bar at any point.
11. 11

    Bleed the rear brake circuit
    Reconnect the 12V battery only after the hydraulic connections are sealed. Top off the master cylinder reservoir with fresh DOT 4 fluid. Bleed the affected rear caliper using a pressure or vacuum bleeder, or two-person manual bleed, until clear bubble-free fluid flows. Torque the bleeder screw to specification between cycles. Maintain reservoir level above MIN throughout.
    ⚠Never let the master cylinder run dry — this can introduce air into the iBooster and require a Tesla-tool-assisted bleed.
    ℹ️Tesla recommends full brake fluid replacement every 2 years regardless of mileage. If due, bleed all four corners with fresh DOT 4 now.
    Torque spec

    Bleeder Screw14 Nm (10 lb-ft)

Reassembly

1. Confirm reservoir is at MAX with fresh DOT 4 fluid and cap is secured.
2. Reinstall the rear wheel; hand-thread all lug nuts before applying torque.
3. Lower the vehicle to the ground.
4. Torque lug nuts in a star pattern to specification.
5. Re-enable Auto Hold and Creep in the touchscreen settings if previously disabled.
6. Wipe any fluid residue from the caliper, hose, and surrounding underbody.

Verification

• With the vehicle still stationary, press the brake pedal repeatedly — pedal should become firm within 2-3 strokes and hold steady under foot pressure with no slow sink.
• Inspect the new hose, banjo joint, and hard line fitting under pedal pressure for any weeping. Check again after a 5-minute brake-applied dwell.
• Check the touchscreen for any active brake-related alerts (ABS, EPB, iBooster). If a 'Brake System Needs Service' or similar alert is present and will not clear, an ABS module bleed via Tesla service tooling may be required.
• Perform a low-speed test stop in a safe area, then a moderate stop, confirming straight tracking and normal pedal feel before road use.
• Re-inspect the banjo fitting and hard line connection after the first 50 miles for any seepage.
• Note: Tesla recommends full brake fluid service every 2 years — log this date so the next interval is known.

More procedures for this vehicle