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10.8 - Brakes

Type: Four-wheel disc, electro-hydraulic boost

Calipers and Rotors: Factory Ford Super Duty, four corners

Pads and Rotors: PowerStop Z36 Truck & Tow, front and rear

Booster: Bosch Gen 2 iBooster (see Brake Booster)

Master Cylinder: Wilwood Tandem Compact, 1-1/8" bore

Park Brake: Factory drum-in-hat, mechanical lever

ABS: None. Tone rings and wheel speed sensors omitted at both axles.

Axle-side brake hardware and system sizing for the Super Duty axles. The booster, master cylinder mounting, adapter, harness, firewall plate, and plumbing are documented on the Brake Booster page.

Calipers and Rotors

Corner Hardware
Front Factory Super Duty caliper and rotor (Front Axle, Dana 60)
Rear Factory Super Duty caliper and rotor with drum-in-hat park brake (Rear Axle, Sterling 10.5)
Pads and Rotors PowerStop Z36 Truck & Tow kit, front and rear, 2005-2007 F-250/F-350 SRW application1

Kit Year Range

The Z36 kit application is listed as 2005-2007. The donor axles can be 2005-2010. Match the kit to the donor axle years before ordering.

Booster and Master Cylinder

Specification Value
Booster Bosch Gen 2 iBooster, direct mechanical pushrod, M8x1.251
Pedal Ratio Approximately 4:1; verification ⚠️ TBD #301
Master Cylinder Wilwood Tandem Compact, 1-1/8" bore2
MC Adapter Back Bay Customs (see Brake Booster)
Harness ⚠️ TBD #105 — Tulay's Gen 2 or EVcreate kit (see Brake Booster)
Firewall Plate 60x80mm pattern (see Brake Booster)

Master Cylinder Sizing

The 1-1/8" bore is sized for knockback margin with the Super Duty calipers, not steady-state caliper volume. It supersedes the 1.00" bore chosen for the TJ Rubicon calipers.2

Park Brake

Factory drum-in-hat in the rear rotors, mechanical lever. Cables built at full droop.1

Lines and Proportioning

  • Braided flex hoses at each axle, measured at full droop (⚠️ TBD #86); plumbing on the Brake Booster page
  • Adjustable proportioning valve on the rear circuit (⚠️ TBD #60). With no ABS this valve is the only rear lockup control, so set it on a low-grip surface rather than by the bias figure alone
  • Front/rear bias starting point approximately 62/381

Outstanding Items

TBD tracker unavailable

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Build Tasks

  • Confirm the Back Bay Customs adapter fits the 1-1/8" Tandem Compact (vendor confirmed it against the 1.00" 260-15542)
  • Match the Z36 kit application to the donor axle years
  • Measure flex hose and park brake cable lengths at full droop
  • Cite OEM or vendor sources for the Z36 kit application, pushrod thread, and pedal ratio

  1. Owner build notes, 2026-09-16 — Z36 kit application, pushrod thread, park brake cable and hose lengths at full droop, 62/38 bias starting point. Not yet backed by an OEM or vendor citation; see Build Tasks. ↩↩↩↩

  2. Owner decision, 2026-09-16 — Wilwood Tandem Compact 1-1/8" bore, sized for knockback margin with the Super Duty calipers. Supersedes the 1.00" 260-15542 selected 2026-05-30 for the TJ Rubicon calipers. Wilwood lists the 1-1/8" Tandem Compact as 260-15541 (noted on the Brake Booster page, checked 2026-05-30); confirm the part number and the Back Bay adapter fitment before ordering. ↩↩