This procedure covers replacement of a single damaged or corroded brake line on a 2015-2020 Ford F-150 with 5.0L V8, including fitting removal, line routing, and system bleeding.

Warnings

Tools required

Parts

• Pre-flared brake line (correct length and thread) × 1 — Measure original or use OEM part number
• Brake line retaining clips × 2 — As needed for routing
• Copper crush washers (if banjo fittings used) × 2 — Use OEM specification

Fluids

• Motorcraft DOT 4 LV Brake Fluid — 1 qt

Preparation

1. Park vehicle on level ground and place wheel chocks behind wheels that will remain on ground
2. Locate the damaged brake line section and identify both connection points (junction block, caliper, wheel cylinder, or ABS module)
3. If working near rear axle, identify whether line runs along frame rail or over rear axle housing
4. Purchase or fabricate correct replacement line with proper fittings and length - pre-flared lines are strongly recommended over field flaring
5. Apply penetrating oil to line fittings at both ends and allow 15-30 minutes to soak if corrosion is present
6. Raise vehicle and support securely on jack stands at appropriate lift points per owner's manual
7. Remove wheel if brake line connects to caliper or wheel cylinder and access is restricted
8. Place catch pan under work area to collect brake fluid spillage

Procedure

1. 1

   Relieve brake line pressure and prepare connections
   With vehicle off and ignition off, pump brake pedal 15-20 times to deplete any vacuum assist and equalize pressure. Identify the exact routing of the damaged line and note any retaining clips, brackets, or grommets securing it to the frame or body. Take photos of routing for reference during installation.
2. 2

   Remove line retaining hardware
   Using appropriate tools, remove any retaining clips, brackets, or rubber grommets securing the brake line along its route. Note the location and orientation of each clip for reinstallation. If clips are rusted or damaged, replace them to prevent line vibration and chafing.
3. 3

   Disconnect upper fitting first
   Starting with the higher connection point (to minimize fluid loss), use a line wrench of the correct size to loosen the brake line fitting. Hold the component fitting stationary with a backup wrench to prevent turning the component body. Once loosened, unthread by hand and immediately cap or plug the component port to prevent fluid loss and contamination. Allow fluid to drain into catch pan.
   ⚠Never use standard open-end wrenches on brake line fittings - they will round the soft brass or steel hex. Use only six-point flare nut wrenches or line wrenches.
4. 4

   Disconnect lower fitting
   Move to the lower connection point and repeat the disconnection process using proper line wrenches. If the fitting is at a caliper or wheel cylinder, use a backup wrench on the component bleeder boss or inlet to prevent damage. For rigid lines threaded into ABS modules or junction blocks, be especially careful not to cross-thread or damage aluminum ports. Cap or plug immediately after removal.
5. 5

   Remove old brake line
   Once both fittings are disconnected, carefully extract the old brake line from its routing path. Note how it passes through frame holes, around suspension components, and clears moving parts like the driveshaft, exhaust, or steering linkage. If the line passes through rubber grommets in the frame, remove and inspect grommets for reuse.
6. 6

   Prepare and route new brake line
   Compare new line to old line to verify correct length and fitting configuration. Clean fitting threads on components with a wire brush and inspect for damage. Route the new line following the exact same path as the original, ensuring it does not contact exhaust components, sharp edges, or moving parts. Leave adequate slack to prevent tension during suspension movement but avoid excessive loops that could kink.
   ⚠Brake lines must maintain minimum 25mm (1 inch) clearance from exhaust components and must not rub against sharp edges or moving suspension parts. Incorrect routing can cause line failure.
7. 7

   Install upper fitting
   Thread the upper fitting into its component port by hand for at least 3-4 full turns to ensure proper thread engagement. If resistance is felt immediately, stop and verify alignment - do not force. Once hand-tight, use a line wrench to tighten to specification while holding the component stationary with a backup wrench.
   Torque spec

   Line Fittings26 Nm (19 lb-ft)
8. 8

   Install lower fitting
   Thread the lower fitting by hand into its component port, ensuring at least 3-4 turns of hand engagement. Verify the line is not twisted or kinked between connection points. Once hand-tight, torque to specification using proper line wrench technique.
   Torque spec

   Line Fittings26 Nm (19 lb-ft)
9. 9

   Install retaining clips and secure line
   Install all retaining clips, brackets, and grommets in their original positions to secure the brake line. Ensure clips are fully seated and the line is held firmly without crushing. Verify the line has proper clearance from all moving parts, exhaust, and sharp edges throughout the full range of suspension travel.
10. 10

    Bleed brake system at affected circuit
    Fill the master cylinder reservoir to the MAX line with fresh Motorcraft DOT 4 LV brake fluid. Beginning with the wheel furthest from the master cylinder on the affected circuit, attach clear tubing to the bleeder screw and submerge the other end in a container of clean brake fluid. Have an assistant pump the pedal 5 times and hold, then open the bleeder screw until fluid flow stops and close. Repeat until no air bubbles appear. Move to the next closest wheel on the circuit and repeat.
    ⚠️Never allow the master cylinder reservoir to run dry during bleeding or air will enter the ABS module, requiring a scan tool with ABS bleed function to purge.
    Torque spec

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

    Verify system integrity and pedal feel
    With engine off, pump brake pedal firmly 20-30 times. Pedal should become firm and hold position without sinking. Check all fittings for leaks while assistant applies firm pedal pressure. Start engine (brake booster assist will engage) and verify pedal remains firm with slight drop when vacuum applies. Inspect entire new line routing for any seepage.
    ⚠️A spongy or sinking brake pedal indicates air in the system or a leak. Do not drive the vehicle until a firm pedal is achieved and all leaks are corrected.
12. 12

    Reinstall wheel and test
    If wheel was removed, reinstall and torque lug nuts in a star pattern to specification. Lower vehicle from jack stands. Top off brake fluid reservoir to MAX line. Perform a low-speed brake test in a safe area (parking lot) to verify proper braking function before returning to normal service.
    Torque spec

    Wheel Lug Nuts140 Nm (103 lb-ft)

Reassembly

1. Ensure all brake line retaining clips are installed and line routing matches original path exactly
2. Verify minimum 25mm clearance from exhaust and no contact with moving suspension components
3. Double-check that both line fittings are torqued to 26 Nm (19 lb-ft) using a line wrench
4. Confirm master cylinder reservoir is filled to MAX line with Motorcraft DOT 4 LV fluid only
5. Check for fluid leaks at both fittings while assistant holds firm brake pedal pressure

Verification

• With engine off, pump brake pedal - it must become firm and not sink to the floor when held under constant pressure for 30 seconds
• Start engine and verify pedal height drops slightly as vacuum assist engages, then remains firm
• Visually inspect both line fittings and the entire new line routing for any signs of brake fluid seepage or dripping
• Perform a test drive in a safe area at low speed (under 25 mph) to verify braking response is normal with no pedal fade or pull to one side
• Re-check all fittings for leaks after test drive and verify fluid level has not dropped in reservoir
• If equipped with ABS, verify the ABS warning light is not illuminated on the instrument cluster
• Schedule a follow-up inspection after 50-100 miles to re-check fittings and fluid level

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