Brake Caliper - Front

Remove and replace the front brake caliper on a 2009 Aston Martin DB9, including brake line disconnection, mounting hardware removal, and brake system bleeding.

Warnings

Tools required

Parts

• Front brake caliper (left or right as needed) × 1 — Use OEM specification
• Brake line copper crush washers × 2 — Two washers per banjo bolt fitting
• Threadlocker (medium strength) × 1 — Loctite 243 or equivalent
• Brake pads (if replacing caliper) × 1 — Use OEM specification - typically replaced with caliper

Fluids

• DOT 4 low-viscosity brake fluid — 0.5 qt

Preparation

1. Park vehicle on level, solid ground and engage parking brake
2. Place wheel chocks behind rear wheels
3. Loosen front wheel lug nuts 1/2 turn while vehicle is on ground
4. Raise front of vehicle with floor jack at designated jacking points (consult owner's manual for locations)
5. Support vehicle securely on jack stands rated for vehicle weight - never rely on jack alone
6. Remove front wheel completely
7. Locate brake fluid reservoir in engine compartment and check fluid level - mark current level for reference
8. Place absorbent pads or cardboard under brake caliper area to catch fluid spillage
9. Have brake fluid catch container ready for line disconnection

Procedure

1. 1

   Prepare brake fluid reservoir
   Remove approximately 1/3 of brake fluid from the master cylinder reservoir using a turkey baster or fluid syringe. Transfer to a sealed waste container - do not reuse old brake fluid. This prevents reservoir overflow when the new caliper piston is compressed and prevents spillage during line disconnection. Do not allow fluid level to drop below MIN mark.
2. 2

   Disconnect brake line from caliper
   Locate the brake line banjo bolt connecting the flexible brake hose to the caliper body. Position the brake fluid catch container directly below the connection point. Using the appropriate wrench or socket (verify exact size against Aston Martin service data), slowly loosen and remove the banjo bolt. Brake fluid will flow out - this is normal. Remove the bolt completely along with the two copper crush washers (one on each side of the banjo fitting). Immediately plug the brake line end with a rubber cap or wrap tightly with plastic wrap and tape to minimize fluid loss and contamination. Discard the old copper washers - they must not be reused. Note: Using the appropriate box-end wrench or socket, slowly loosen and remove the banjo bolt (verify exact size against Aston Martin service documentation). Note: Using the correct size wrench or socket for the banjo bolt head (verify size against factory documentation), slowly loosen and remove the banjo bolt.
3. 3

   Remove caliper mounting bolts
   The DB9 front caliper is a fixed monobloc (opposed-piston) unit secured by two large mounting bolts that thread directly into the hub carrier. Verify mounting configuration against Aston Martin service documentation. These are typically located at the rear of the caliper assembly. Using the appropriate socket (verify exact size and type against Aston Martin service documentation), remove both caliper bracket bolts completely. These bolts are tightened to a high torque and may require substantial force or penetrating oil if corroded. Keep track of any shims or spacers behind the caliper bracket. Note: Using the appropriate socket (verify exact socket type and size against Aston Martin service data), remove both caliper bracket bolts completely. These bolts are torqued to a high specification and may require substantial force or penetrating oil if corroded. Note: Using the correct socket for your DB9 (confirm E-Torx, Torx, or hex size against factory documentation), remove both caliper bracket bolts completely. Note: These bolts are very tight and may require substantial force or penetrating oil if corroded. Verify the exact caliper bracket bolt torque against Aston Martin factory service documentation before reassembly.
4. 4

   Remove caliper assembly
   With both mounting bolts removed, carefully lift the fixed monobloc caliper off the brake rotor. The brake pads are retained inside the caliper by a pad retaining pin/clip - remove the pin and withdraw the pads if reusing. Inspect the brake rotor surface for scoring, heat cracks, or excessive wear while exposed. Inspect the brake rotor surface for scoring, heat cracks, or excessive wear while exposed.
5. 5

   Prepare new caliper
   Unbox the new caliper and verify it matches the old unit (left vs right side, mounting configuration, bleeder screw location). Ensure the caliper pistons are fully retracted. Because this is an opposed-piston caliper, use a proper brake piston spreader tool to push each piston back evenly into its bore - do NOT use a single C-clamp, which can cock the pistons. Do NOT force crooked or at an angle. Check that the bleeder screw moves freely (crack it loose slightly then retighten). Clean any protective coating or shipping grease from mounting surfaces and piston face.
6. 6

   Prepare mounting hardware
   Clean the caliper mounting bolt threads with a wire brush. Inspect bolt threads and hub carrier threaded holes for damage or corrosion. Verify against Aston Martin service data whether the caliper mounting bolts are reusable and whether threadlocker is specified; many of these are one-time-use or pre-coated fasteners that must be replaced rather than re-coated. If OEM specifies threadlocker on reusable bolts, apply a thin coat of the specified medium-strength threadlocker (e.g., Loctite 243 or equivalent) to the threads. Clean the hub carrier mounting face where the caliper bracket seats to ensure proper contact.
7. 7

   Install brake pads and position caliper
   If using new brake pads (recommended when replacing caliper), install them into the caliper bracket according to manufacturer orientation - anti-rattle clips and shims must be correctly positioned. Carefully position the caliper assembly over the brake rotor, aligning the bracket mounting holes with the threaded holes in the hub carrier. Ensure brake pads are properly seated on both sides of the rotor and the rotor is centered in the caliper.
8. 8

   Install and torque caliper bracket bolts
   Thread both caliper bracket bolts into the hub carrier by hand to ensure proper thread engagement. Once both are hand-tight, torque each bolt to the Aston Martin-specified value (verify in official service documentation) in a crossing pattern (alternate between bolts, tightening gradually). This is a critical safety torque specification - use a calibrated torque wrench and verify the setting before applying. The bolts should be very tight. Note: Once both are hand-tight, torque each bolt to the Aston Martin specified value (verify exact torque against OEM service data) in a crossing pattern (alternate between bolts, tightening gradually). Note: Once both are hand-tight, torque each bolt to the Aston Martin factory-specified value (verify in official service documentation) in a crossing pattern (alternate between bolts, tightening gradually).
   Torque spec

   Caliper Bracket Bolts110 Nm (81 lb-ft)
9. 9

   Connect brake line with new washers
   Remove the plug or wrap from the brake line end. Install one NEW copper crush washer onto the banjo bolt, then thread the bolt through the brake line banjo fitting. Position the banjo fitting onto the caliper brake fluid inlet port with the second NEW copper washer between the fitting and caliper body. Ensure proper alignment with no twisting of the flexible brake hose. Thread the banjo bolt into the caliper by hand, then torque to the Aston Martin specified value (verify exact torque against OEM service data) using a torque wrench. This is a CRITICAL torque specification - over-tightening will damage the washers and cause leaks; under-tightening will cause brake fluid leakage and system failure. Note: Thread the banjo bolt into the caliper by hand, then torque to the Aston Martin-specified value (verify in official service documentation) using a torque wrench. Note: Thread the banjo bolt into the caliper by hand, then torque to the Aston Martin factory-specified banjo bolt value (verify in official service documentation) using a torque wrench.
   Torque spec

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

    Bleed brake caliper
    Refill the brake fluid reservoir to the MAX line with fresh brake fluid of the Aston Martin-specified type (verify DOT rating/spec in official service documentation). Locate the bleeder screw on the caliper body (typically on top/rear). Place one end of clear bleeding tubing over the bleeder screw nipple and submerge the other end in a container with 1-2 inches of fresh brake fluid. Have an assistant pump the brake pedal 3-4 times and hold firm pressure. While pedal is held, crack open the bleeder screw 1/4-1/2 turn - fluid and air bubbles will flow through the tube. Close the bleeder screw BEFORE the assistant releases the pedal. Repeat this process until no air bubbles appear in the tubing and only clean fluid flows (typically 5-10 cycles). Check reservoir level frequently and top off - never let it drop below MIN. When bleeding is complete, snug the bleeder screw to the Aston Martin-specified value (verify in official service documentation) - DO NOT overtighten as these are easily damaged. Note: When bleeding is complete, torque the bleeder screw to the Aston Martin specified value (verify exact torque against OEM service data) - DO NOT overtighten as these are easily damaged. Note: When bleeding is complete, snug the bleeder screw to the manufacturer-specified torque (typically low, around 7-10 Nm - verify in factory documentation) - DO NOT overtighten as these are easily damaged.
    Torque spec

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

    Check for leaks and verify fluid level
    Wipe all brake fluid residue from the caliper and brake line connections using clean shop rags. With the assistant maintaining firm brake pedal pressure, carefully inspect the banjo bolt connection and bleeder screw for any signs of fluid seepage. Any leak indicates improper installation - the connection must be corrected immediately. Check the brake fluid reservoir and top off to the MAX line with fresh DOT 4 brake fluid. Ensure reservoir cap is properly sealed.
12. 12

    Reinstall wheel and lower vehicle
    Mount the wheel back onto the hub, ensuring it seats properly against the hub face. Thread all wheel lug bolts by hand to prevent cross-threading, supporting the wheel to align the bolt holes. Tighten the lug bolts in a star pattern to snug by hand. Lower the vehicle until the tire just contacts the ground but most weight is still on the jack stands. Torque the wheel bolts to the Aston Martin specification (approximately 150 Nm / 111 lb-ft - verify exact value in official service documentation) in a star pattern. Fully lower the vehicle and remove jack stands. Perform final lug nut torque check at full vehicle weight. Note: Mount the wheel back onto the hub, ensuring it seats properly against the hub face. Thread all wheel bolts by hand to prevent cross-threading. Note: Torque the wheel bolts to the Aston Martin specified value (verify exact torque against OEM service data) in a star pattern. Note: Torque the wheel fasteners to the Aston Martin factory specification (verify exact value in official service documentation) in a star pattern.

Reassembly

1. Wheel installation is covered in the main procedure steps
2. Ensure all tools and materials are removed from under vehicle before test driving
3. Dispose of old brake fluid and copper washers according to local environmental regulations - do not pour down drains

Verification

• With vehicle still on jack stands (wheel installed), have an assistant pump the brake pedal multiple times - it should become firm and hold pressure. A soft or spongy pedal indicates air remains in the system and further bleeding is required
• Perform a final visual inspection of the banjo bolt connection and bleeder screw for any signs of fluid leakage with pedal pressure applied
• After lowering vehicle completely, start engine and pump brake pedal - the pedal should be firm with normal travel. The brake warning light should not be illuminated
• In a safe area free of traffic, test brakes at low speed (5-10 mph) to verify proper function. The vehicle should stop smoothly without pulling to one side
• Perform a series of moderate stops from 20-30 mph to bed in the new pads/caliper and verify consistent braking performance
• After first test drive, re-check brake fluid reservoir level and top off if needed. Check caliper area for any signs of fluid leakage
• Re-check wheel lug nut torque after first 50-100 miles of driving
• If vehicle pulls to one side during braking, exhibits soft pedal, makes unusual noises, or shows any abnormal brake behavior, STOP driving immediately and have the system inspected by a professional

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