Overview
The Baer Brakes 4302343R SS4 is a red 12 inch rear brake kit built around a 4-piston S4 caliper, made for GM small pattern 10/12 bolt rear axles with a bearing on axle layout and flush mount bearing housing ends. Its bolt pattern is 5×4.75 and 5×5, with 5 lug wheels.
Baer’s backing plate mounts the caliper and contains a one-piece park brake shoe assembly. Paired with a one-piece slotted, drilled, zinc plated rotor, the setup takes DR1 or HB100 pads, with FMSI number DR1-C.
Key features
- S4 four-piston caliper in red, manufactured in Phoenix, AZ
- Powder coated, CNC machined aluminum caliper body from forged or billet stock
- Hard anodized aluminum pistons with stainless steel abutments
- Noise suppression clips and dual dust, weather and pressure seals
- One-piece slotted, drilled, zinc plated rotor
- Stainless braided brake hoses included
Signs of rotor wear
Rotors wear slowly, but certain symptoms point to a problem before the brakes fail. A pulsing pedal or a vibration felt through the steering wheel often means uneven thickness or heat damage. Deep grooves, cracks, or a blue tint on the friction surface are also reasons to pull the wheel and measure.
Rotor thickness should be measured against the minimum stamped on the rotor itself, not against a guess. Surface rust on the zinc plated finish is normal after time outdoors, but rust that flakes off in layers suggests the rotor has been sitting unused or has been exposed to road salt. When replacing a rotor, install new pads at the same time so the pad surface matches the new friction surface.
Specifications
| Brand | Baer Brakes |
|---|---|
| Part number | 4302343R |
| UPC | 844165043997 |
| Sold as | Kit |
| Axle | Rear |
| Axle flange | GM small pattern 10/12 bolt with flush mount bearing |
| Axle housing flange type | Hybrid, 3.150 inch bearing on axle, flush mount |
| Wheel bolt pattern | 5×4.75/5×5.00 |
| Lug count | 5 lug |
| Min wheel diameter | 16.0 inch |
| Rotor outside diameter (rear) | 12.0 inch |
| Rotor type | 1-piece, vented |
| Rotor material | Iron |
| Rotor surface | Slotted, drilled and zinc plated |
| Rotor thickness | 1.02 |
| Caliper | S4, 4 pistons, fixed |
| Caliper color | Red |
| Pad FMSI number | DR1-C |
| Hose material | Steel braided, DOT approved |
| Includes park brake | Yes |
| Template | S113E |
| Grade | Performance |
| Emission code | 6 |
| Country of origin | US |
Vehicle fitment
Other flange designs and bolt patterns are outside the scope of this kit. Confirm your vehicle’s year, model and trim before ordering.
Installation notes
The park brake shoe sits inside the backing plate, but park brake cables are not included and must be sourced separately. Compare the S113E template with your wheel, keeping the 16.0 inch minimum wheel diameter in mind. Lift the vehicle safely and keep grease away from the friction surfaces.
What’s included
- S4 4-piston caliper in red
- 12.0 inch one-piece slotted, drilled rotor
- Backing plate with one-piece park brake shoe assembly
- Stainless braided brake hoses
Not included: Park brake cables and lug nuts.
