Overview
The Baer Brakes SS4 Plus rear brake kit, part number 4302438GB, is a Grabber Blue rear disc brake system for GM small pattern 10/12 bolt bearing-on-axle rear ends with flush mount bearing housings. It uses a four-piston S4 caliper clamping a 13 inch two-piece rotor that is slotted, drilled and zinc plated.
Baer’s backing plate carries the caliper and also houses a modern one-piece park brake shoe assembly, which keeps the parking brake in the rear carrier. The kit is aimed at drivers who want a stronger rear brake setup with a color-matched caliper, on axles that run 17 inch or larger wheels.
Key features
- Four-piston S4 caliper with hard anodized aluminum pistons
- Stainless steel abutments and noise suppression clips included in the caliper
- Two-piece slotted, drilled, zinc-plated rotor with a billet aluminum hat
- Dual seals for dust, weather and pressure protection
- Powder coated Grabber Blue finish
- Pre-assembled rotors with NAS high grade stainless hardware
- Steel braided hoses; caliper made in Phoenix, Arizona
Choosing the right setup
The caliper finish is a cosmetic choice, but the parts behind it do the work. Pad selection matters most for daily driving because the compound sets how the rotor warms and wears. Match the pad material to how the vehicle is used, whether that is commuting, towing or steady trail driving.
Rear brake upgrades often include fresh brake fluid, new hoses and inspected slide pins, since a caliper that cannot move freely loses braking consistency. Measure the rotor against its minimum thickness at each service and replace it once it is worn past that limit. Hardware reused from an older setup should be cleaned and checked before reassembly.
- Replace brake fluid whenever the system is opened
- Check caliper slide pins for free movement
- Inspect the rotor surface for grooves and heat marks
- Torque lug nuts to the specification for the vehicle
Specifications
| Brand | Baer Brakes |
|---|---|
| Part number | 4302438GB |
| UPC | 90127952702 |
| Sold as | Kit |
| Caliper | S4, four-piston, fixed |
| Caliper color | Grabber Blue |
| Rotor type | 2-piece, vented, slotted, drilled, zinc plated |
| Rotor outside diameter | 13.0 inch |
| Rotor thickness | 0.81 |
| Minimum wheel diameter | 17.0 inch |
| Axle flange | GM small pattern 10/12 bolt with flush mount bearing |
| Wheel bolt pattern | 5×4.75/5×5.00 |
| Lug count | 5 lug |
| Brake pad FMSI number | DR1-C |
| Brake hose | Steel braided, DOT approved |
| Template | S135H |
| Emission code | 6 |
| Country of origin | USA |
Vehicle fitment
The 4302438GB kit has no vehicle-by-vehicle fitment on record. Its application is defined by the axle flange, which is GM small pattern 10/12 bolt bearing on axle with flush mount bearing housing ends.
Installation notes
The rotors come pre-assembled with stainless hardware, so the rotor and hat are installed as one piece. The park brake shoe assembly is built into the backing plate and should be checked during the rear brake work. Park brake cables are not supplied with this kit. Clearance against a 17 inch or larger wheel should be confirmed with the S135H template.
What’s included
The kit contains the Grabber Blue S4 caliper, the 13 inch two-piece rotor on its billet aluminum hat, the backing plate with the park brake shoe assembly, and stainless braided hoses with stainless hardware.
Not included: Park brake cables.
