Complete replacement of all hydraulic brake lines on a 2024 Model S Plaid, including hard lines and flexible hoses at all four corners, followed by a full system bleed. This is a safety-critical hydraulic job on a 1,020-hp vehicle with regen-blended braking — any leak or air in the system can cause brake failure.

Warnings

Tools required

Parts

• Front flexible brake hose (left) × 1 — OEM Model S Plaid front LH hose — verify by VIN
• Front flexible brake hose (right) × 1 — OEM Model S Plaid front RH hose — verify by VIN
• Rear flexible brake hose (left) × 1 — OEM Model S Plaid rear LH hose — verify by VIN
• Rear flexible brake hose (right) × 1 — OEM Model S Plaid rear RH hose — verify by VIN
• Hard line set (front-to-rear, master cylinder to splitters) × 1 — OEM-spec pre-formed lines or DOT-approved replacement tubing
• Copper sealing washers for banjo fittings (if used) × 8 — Match OEM size
• Brake line retaining clips × 12 — OEM body/subframe clips
• Bleeder screw dust caps × 4 — Generic

Fluids

• DOT 3 Brake Fluid (verify spec on master cylinder cap by VIN — some 2024 builds may specify DOT 4) — 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 low-voltage battery: on 2024 Model S Plaid this is typically the 16V lithium unit located under the rear seat (verify by VIN — some builds retain the frunk-mounted 12V). Follow the manufacturer-specified disconnection 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. Before lifting: enter the touchscreen and activate Service Mode → Jack Mode (or Controls → Suspension → Jack Mode on consumer UI) to disable air suspension self-leveling.
7. Verify required brake fluid type by reading the master cylinder reservoir cap and cross-referencing the VIN.
8. Loosen all four lug nuts a quarter turn while wheels are on the ground.
9. Lift the vehicle on a hoist using Tesla-approved puck adapters at the four designated lift points; support on stands rated for EV weight.
10. Remove all four wheels.
11. Place fender covers and floor protection under each corner — DOT 3/4 fluid will lift paint within minutes.

Procedure

1. 1

   Document line routing
   Photograph the routing of every hard line and flex hose at all four corners, along the subframe, and across the floor pan tunnel area. Note every retaining clip, grommet, and heat shield location. Replacement lines must follow the original path exactly to avoid contact with HV cabling, drive units, or suspension components.
   ⚠️Brake hard lines on Model S route along the floor pan in close proximity to the HV battery enclosure. Note clearances before disturbing.
2. 2

   Empty the master cylinder reservoir
   Open the frunk and locate the brake fluid reservoir on the master cylinder. Use a clean fluid extractor (turkey-baster type dedicated to brake fluid) to remove as much old fluid as possible. Do NOT let the reservoir run dry into the master cylinder during this step — leave a small amount until lines are disconnected.
3. 3

   Disconnect flex hoses at each caliper
   Working one corner at a time, place a catch bottle under the caliper. Use a line wrench on the hose-to-caliper fitting (or banjo bolt, depending on configuration) and break it loose. Cap the caliper port immediately with a bleeder cap or plug to minimize fluid loss. Repeat at all four corners.
   ⚠Use a flare-nut (line) wrench only — open-end wrenches will round the soft fitting.
   Torque spec

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

   Disconnect flex hoses at body brackets
   At each corner, the flex hose terminates at a hard line at a body or subframe bracket secured by a horseshoe clip. Hold the hose hex with a line wrench, loosen the hard line fitting, then pull the horseshoe clip and free the hose. Discard the old hose.
   Torque spec

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

   Remove hard lines
   Release each hard line from its retaining clips along the subframe, rocker, and floor pan. Loosen the fittings at the master cylinder, ABS/iBooster module, and any junction blocks using a line wrench. Withdraw lines carefully — do not bend or kink. Note: Model S Plaid uses an integrated electronic brake booster; do not disturb its electrical connectors or mounting unless specifically required.
   ⚠️Do not loosen any fitting on an orange-jacketed line or any HV component. Brake hydraulic lines are steel/coated steel and clearly distinct from HV cabling.
   Torque spec

   Line Fittings20 Nm (15 lb-ft)

   Mounting Bolts27 Nm (20 lb-ft)
6. 6

   Inspect calipers, brackets, and mounting points
   With lines removed, inspect each caliper bleeder screw for corrosion and free movement. Inspect caliper slide pins, bracket bolts, and all line bracket mounting points. Replace any damaged hardware now — access will be far worse after reassembly.
   Torque spec

   Caliper Bolts88 Nm (65 lb-ft)

   Bracket Bolts102 Nm (75 lb-ft)

   Caliper Slide Pin Bolts35 Nm (26 lb-ft)
7. 7

   Install new hard lines
   Route new hard lines along the original path documented in Step 1. Start fittings by hand at every junction to avoid cross-threading. Once all fittings are hand-tight and lines sit naturally in their clips, torque each line fitting with a line wrench torque adapter. Reinstall every retaining clip — unsupported lines fatigue and crack from vibration.
   ⚠Cross-threaded fittings on soft brake-line tube nuts will leak under pressure. If a fitting binds, back it out and restart by hand.
   Torque spec

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

   Install new flex hoses
   Install each flex hose at its body bracket first, seat the horseshoe clip fully, then route the hose to the caliper without twisting. Check that the hose does not contact the tire, suspension arm, or any moving component through full steering and full suspension travel. Torque the fittings at both ends.
   ⚠A twisted flex hose will fail prematurely. Verify alignment marks on the hose are straight at both ends.
   Torque spec

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

   Refill master cylinder and perform initial gravity bleed
   Fill the reservoir with the verified-correct fresh brake fluid. Open the bleeder screws at all four calipers with catch bottles attached and allow fluid to gravity-bleed until clear, bubble-free fluid emerges. Keep the reservoir topped off — never let it run dry.
   Torque spec

   Bleeder Screw10 Nm (7 lb-ft)
10. 10

    Pressure bleed at each caliper
    Connect a pressure bleeder to the reservoir at the manufacturer-specified pressure (refer to Tesla Service Manual). Bleed each caliper in the manufacturer-specified sequence — Tesla Service Manual sequence must be verified; do not assume diagonal or longest-line-first conventions apply. Tighten each bleeder screw to spec between pulls.
    ⚠Bleeder screws on aluminum-bodied calipers strip easily. Do not exceed 10 Nm.
    Torque spec

    Bleeder Screw10 Nm (7 lb-ft)
11. 11

    Run ABS/iBooster automated bleed via Service Mode
    With the LV battery reconnected and the vehicle awake, enter Service Mode on the touchscreen and run the brake system bleed routine (this cycles the iBooster and ABS solenoids to purge air from the modulator — air trapped here cannot be removed by manual bleeding alone). Repeat the caliper bleed sequence afterward. Refer to Tesla Service Manual for the exact menu path on 2024 Plaid software.
    ⚠Skipping the automated ABS bleed is the most common cause of a soft pedal after a full line replacement on Model S/X.
12. 12

    Final torque check and leak test
    With the system fully bled, have an assistant apply firm pedal pressure (200+ N) for 60 seconds while you inspect every fitting, junction, and caliper port for weeping. Repeat at full pedal release. 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, snug lug nuts in a star pattern.
2. Lower the vehicle to the ground.
3. Final-torque the lug nuts in a star pattern.
4. Reconnect the low-voltage battery if it was disconnected for the ABS bleed step.
5. Exit Jack Mode and Service Mode via the touchscreen.
6. Allow the air suspension to self-level before moving the vehicle.
7. Top off the brake fluid reservoir to the MAX line and reinstall the cap.

Verification

• Before moving the vehicle: with the brake pedal depressed firmly, verify a hard, high pedal that does not sink under sustained pressure. A sinking pedal indicates a leak or a master cylinder issue — do not drive.
• Check the touchscreen for any brake-system warnings, ABS faults, or iBooster faults. Clear codes only after confirming no active faults remain.
• At very low speed in a safe area, perform 3–5 progressively firmer brake applications to seat pads and confirm normal pedal feel.
• Re-inspect every fitting for leaks after the first 10 miles and again after 100 miles — new fittings can weep as they seat.
• Record the service date and mileage. Tesla recommends brake fluid replacement every 2 years regardless of mileage; this job resets that interval.
• Torque lug nuts to spec (Wheel Lug Nuts) again after 50 miles — aluminum hubs can settle.

More procedures for this vehicle