Complete replacement of all brake lines (metal and flexible) from master cylinder to all four corners, followed by comprehensive system bleeding and verification.

Warnings

Tools required

Parts

• Complete brake line set for 2015 Kia Forte × 1 — Use OEM specification or pre-bent NiCopp kit
• Front flexible brake hoses (left and right) × 2 — Use OEM specification
• Rear flexible brake hoses (left and right) × 2 — Use OEM specification
• Brake line fittings and clips × 1 — Included with line set or purchase separately
• Copper crush washers for banjo fittings × 8 — Use OEM specification

Fluids

• DOT 4 Brake Fluid — 2 qt

Preparation

1. Park vehicle on level surface and chock rear wheels securely
2. Raise vehicle and support on four jack stands at manufacturer jacking points
3. Remove all four wheels and set aside
4. Photograph all brake line routing, bracket positions, and connections from multiple angles
5. Apply penetrating oil to all brake line fittings and allow to soak minimum 30 minutes
6. Use turkey baster or pump to remove as much old brake fluid as possible from master cylinder reservoir
7. Clean master cylinder reservoir area thoroughly to prevent contamination
8. Place drip pans under all four brake corners and along frame rails where lines will be disconnected
9. Identify and mark all bracket locations along frame rails and suspension components

Procedure

1. 1

   Disconnect and remove front flexible brake hoses
   Starting at the front left wheel, disconnect the flexible brake hose from the hard line at the frame bracket using flare nut wrench. Hold the hose end fitting with backup wrench to prevent twisting. Remove banjo bolt connecting hose to caliper, noting position of copper crush washers. Repeat for right side. Cap all open connections immediately to prevent fluid loss and contamination.
   ⚠Brake fluid will drain from disconnected lines. Position catch containers before loosening fittings.
2. 2

   Remove front hard brake lines from master cylinder to frame brackets
   Locate hard line connections at master cylinder. Using flare nut wrenches, carefully disconnect the two front lines from master cylinder ports. Work slowly to avoid rounding off fittings. Trace lines along frame rail and release from all mounting clips and brackets. Remove complete front hard lines from vehicle. Note any differences between left and right routing.
   ⚠Flare nut fittings are easily damaged. Use proper 6-point flare nut wrenches, not open-end wrenches.
3. 3

   Disconnect and remove rear flexible brake hoses
   At rear wheels, disconnect flexible brake hoses from hard lines at frame mounting points. Remove banjo bolts connecting hoses to rear calipers or wheel cylinders. Remove old copper crush washers and discard. Cap all openings immediately.
   ℹ️Rear brake hoses may have orientation marks. Note position for installation of new hoses.
4. 4

   Remove rear hard brake lines
   Trace rear brake lines from master cylinder along frame rail to rear axle area. Disconnect at master cylinder using flare nut wrench. Release all mounting clips and brackets along the way. For lines crossing rear suspension, note exact routing to avoid interference. Remove proportioning valve connections if equipped. Remove complete rear hard lines from vehicle.
   ℹ️Some brake lines may be routed through frame rail channels. May require fish wire or similar tool for installation of new lines.
5. 5

   Prepare and test fit new brake lines
   If using pre-bent line set, identify each line and compare with photos of original routing. If fabricating custom lines, use old lines as templates. Ensure all lines have proper double flares at both ends. Test fit each line before final installation to verify correct length and routing. Verify that lines will not contact exhaust, suspension components, or frame edges that could cause abrasion.
   ⚠️Inspect all flares under magnification. Any cracks, splits, or imperfections will cause system failure. Remake any questionable flares.
6. 6

   Install rear hard brake lines
   Begin installation at master cylinder. Thread fittings by hand first to ensure proper engagement. Snug fittings finger-tight, then route lines along frame following original path. Install all mounting clips and brackets loosely. Verify clearance from all moving parts, exhaust, and sharp edges. Once routing is confirmed correct, tighten master cylinder fittings with flare nut wrench (do not overtighten - typical spec is 11-14 Nm for flare fittings). Tighten mounting brackets per torque specification.
   ⚠Over-torquing flare nut fittings will damage the flare and cause leaks. Snug plus 1/8 turn is typically sufficient.
   Torque spec

   Bracket Bolts97 Nm (71 lb-ft)
7. 7

   Install front hard brake lines
   Route front hard lines from master cylinder to frame brackets where flexible hoses will connect. Follow same installation procedure as rear lines: hand-start all fittings, confirm routing and clearances, install brackets loosely, then tighten fittings and brackets. Ensure lines are properly secured in all mounting clips.
   Torque spec

   Bracket Bolts97 Nm (71 lb-ft)
8. 8

   Install front flexible brake hoses
   Install new front flexible brake hoses with NEW copper crush washers on banjo fittings at calipers. Thread banjo bolts by hand first. Connect hose to hard line at frame bracket, ensuring hose is not twisted. Verify hose has adequate slack for full steering and suspension travel. Turn steering wheel lock-to-lock and compress/extend suspension to verify no binding or excessive stretching. Torque banjo bolts and frame bracket fittings to specification. Repeat for both sides.
   ⚠️Brake hoses must have proper slack. Hose stretched tight during suspension movement will fail catastrophically.
   Torque spec

   Mounting Bolts26 Nm (19 lb-ft)
9. 9

   Install rear flexible brake hoses
   Install rear flexible hoses using NEW copper crush washers at banjo connections. Connect to hard lines at frame mounting points. Verify proper orientation using marks noted during removal. Check for adequate slack during full suspension articulation. Bounce rear suspension while observing hoses for binding or excessive tension. Torque all connections to specification.
   Torque spec

   Mounting Bolts26 Nm (19 lb-ft)
10. 10

    Initial brake system fill and check for leaks
    Fill master cylinder reservoir with fresh DOT 4 brake fluid to MAX line. Slowly pump brake pedal 10-15 times to begin moving fluid through system. Check ALL connections for leaks. Top off reservoir as level drops. Continue pumping and checking until fluid reaches all four corners. Do NOT start vehicle or apply full pressure yet. Address any leaks immediately before proceeding.
    ⚠️Any leak, no matter how small, must be corrected before system pressurization. Even minor weeping indicates improper installation.
11. 11

    Bleed brake system - rear wheels
    Begin bleeding at wheel furthest from master cylinder (typically right rear). Attach clear tubing to bleeder screw and submerge other end in container with clean brake fluid. Have assistant apply steady pressure to brake pedal. Open bleeder screw with 10mm wrench. Fluid and air will flow out. Close bleeder before pedal reaches floor. Repeat until fluid flows clear with no air bubbles. Torque bleeder screw to specification. Repeat process for left rear. Maintain reservoir level above MIN throughout bleeding process.
    ⚠️Never let reservoir run dry during bleeding. Air entering master cylinder requires complete restart of bleeding process.
    ⚠Bleeder screws are fragile. Use proper 6-point wrench and do not over-torque.
    Torque spec

    Bleeder Screw10 Nm (7 lb-ft)
12. 12

    Bleed brake system - front wheels
    Continue bleeding process at right front wheel, then left front wheel, using same procedure as rear. For each wheel: pump pedal, open bleeder, close bleeder before pedal bottoms. Continue until fluid is clear with no bubbles. Some air may be trapped in ABS unit - may require multiple rounds of bleeding or use of scan tool for ABS bleeding sequence. Torque all bleeder screws to specification after bleeding complete.
    Torque spec

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

    Perform final system pressurization and leak check
    With engine running, pump brake pedal firmly 20-30 times to build full system pressure and activate ABS unit. Hold firm pedal pressure for 30 seconds while assistant inspects every connection for leaks. Check master cylinder, all hard line fittings, flexible hose connections, bleeder screws, and banjo bolts. Pedal should feel firm and not sink. If pedal feels spongy, additional bleeding is required. Top off reservoir to MAX line.
    ⚠️Spongy pedal indicates air in system. Do not drive vehicle until pedal is firm and consistent.
14. 14

    Reinstall wheels and perform controlled brake test
    Install all four wheels and torque lug nuts in star pattern to specification. Lower vehicle to ground. In safe area with no traffic, perform controlled brake tests starting at low speed (5-10 mph). Verify straight stopping with no pulls. Gradually increase speed and brake force. Test emergency stop from 30 mph in safe area. Monitor for leaks, unusual noises, or pedal irregularities. If any issues arise, stop immediately and inspect system.
    ⚠️First test drive must be in controlled environment with adequate stopping distance. Brake system behavior may differ from original until bedded in.
    Torque spec

    Wheel Lug Nuts140 Nm (103 lb-ft)

Reassembly

1. Ensure all brake line mounting clips and brackets are properly secured
2. Verify no brake lines contact exhaust, suspension, or frame edges
3. Double-check all flare nut and banjo bolt connections for proper torque
4. Confirm flexible brake hoses have adequate slack for full steering and suspension travel
5. Top off brake fluid reservoir to MAX line with fresh DOT 4 fluid
6. Dispose of old brake fluid and contaminated materials according to local regulations

Verification

• With engine running, brake pedal should be firm within first 1-2 inches of travel and not sink under sustained pressure
• No visible leaks at any connection point after full system pressurization
• Vehicle stops straight with no pulling to either side during moderate braking
• ABS activates normally during controlled ABS test (if equipped)
• Brake warning light is off on instrument cluster
• Re-inspect all connections after 50-100 miles of driving and check fluid level
• Perform follow-up inspection after 500 miles: check all connections for seepage, verify proper fluid level, and road test for proper brake operation

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