Overview
The Baer Brakes SS4 rear brake kit, part number 4402007FR-2, is a complete rear disc brake system finished in Fire Red for Jeep Wrangler JK, Wrangler JL and Gladiator JT models that use the factory rear end. It pairs a 4-piston S4 caliper with a 13.0 inch vented rotor and is intended for the rear axle of the vehicles listed below.
Pads follow the DR1-C pattern, FMSI number DR1-C, and the dual seals guard against dust, weather and pressure. Rotors arrive pre-assembled with NAS high grade stainless hardware, and all mounting brackets and hardware are included. Wheel fit cannot be guaranteed for every wheel style, so lay the S193H template against your wheel before mounting. The SS4 Plus version is made for most wheels 17 inch or larger.
Key features
- Two-piece 4-piston S4 caliper manufactured in Phoenix, Az
- CNC machined from US-sourced forged or billet aluminum
- Powder coated Fire Red caliper finish
- Hard anodized aluminum pistons with stainless steel abutments
- Noise suppression clips included in the caliper assembly
- Dual seals for dust, weather and pressure
- 1-piece slotted and zinc-plated vented rotor
- Floating caliper design with pre-assembled stainless hardware
Choosing rear brake upgrades
Rear disc brakes do a larger share of the work than many owners expect when the vehicle is loaded, towed or driven down steep grades. A rear kit works as a system, so the caliper, pads, rotor and hoses should be matched to how the vehicle is used. Heavier trail use and frequent highway driving put different demands on the same hardware, and that is worth weighing before purchase.
Pads usually wear faster than rotors, so check pad thickness at every tire rotation and replace them before the backing plate contacts the rotor. Inspect the rotor face for deep grooves, heat cracking or a pulsing pedal, which point to uneven wear or runout. Brake fluid absorbs moisture over time, so a periodic fluid change helps the system respond consistently.
- Bed in new pads gradually before heavy braking
- Re-torque lug nuts after the first wheel removal
- Replace hoses that show cracking or bulging
- Keep caliper slide pins clean and lubricated
Specifications
| Brand | Baer Brakes |
|---|---|
| Part number | 4402007FR-2 |
| UPC | 90127995549 |
| Caliper | S4, 4-piston, floating |
| Caliper color | Fire Red |
| Caliper finish | Powder coated |
| Rotor outside diameter | 13.0 inch |
| Rotor type | 1-piece, slotted and zinc plated, vented |
| Rotor thickness | 0.81 |
| Minimum wheel diameter | 17.0 inch |
| Lug count | 5 Lug |
| Wheel bolt pattern | 5×5.00 in |
| Pad type | DR1-C (FMSI) |
| Template | S193H |
| Axle | Rear |
| Park brake | No, re-uses OE |
| Brake hoses | Not included |
| Country of origin | USA |
Vehicle fitment
It fits the 2007–2018 Jeep Wrangler (JK), 2018–2025 Jeep Wrangler (JL) and 2020–2025 Jeep Gladiator (JT), each with the w/OE Rear End.
It does not cover the Wrangler TJ or LJ, the Jeep Liberty or the Cherokee XJ. Confirm your vehicle’s year, model and trim before ordering.
Installation notes
Rotors arrive pre-assembled, and the brackets and hardware are included, so the job is mounting the rotor and caliper assemblies. Brake hoses are not supplied, and the parking brake re-uses your existing OE components. Check wheel clearance with the S193H template against the 17.0 inch minimum wheel diameter before mounting. Brake components are safety critical, so have a qualified technician verify the installation before driving.
What’s included
Sold as a kit: the S4 calipers, pre-assembled 1-piece rotors with NAS high grade stainless hardware, and all mounting brackets and hardware.
Not included: Brake hoses.
