Overview
The Baer Brakes SS4 rear brake system, part number 4302332S, is a silver four-piston disc brake kit for GM small pattern 10/12 bolt bearing-on-axle rear ends with 5×4.75 and 5×5 inch bolt circles. Baer built it around a 12-inch slotted, drilled, zinc plated rotor and a fixed S4 caliper, with a one-piece park brake shoe assembly housed in the backing plate.
The 12-inch SS4 is sized for wheels 16 inches or larger. Wheel fit can vary by style, so check the S113E template against the wheels you plan to run before mounting.
Key features
- Four-piston S4 caliper with hard anodized aluminum pistons and stainless steel abutments
- Dual dust, weather and pressure seals on the caliper
- One-piece slotted, drilled, zinc plated 12.0 inch rotor
- Backing plate serves as caliper mount and houses the park brake shoe assembly
- Braided brake hoses included, DOT approved
- Powder coated silver finish; CNC machined from forged or billet aluminum
- Pad FMSI number DR1-C
Pads, rotor and wear
A 12-inch rotor has a smaller swept area than larger rotors, so heat builds faster under repeated hard stops. Pad choice and rotor condition matter more in that case, especially on heavier vehicles or steep descents. Keep the rotor surface clean and check the pads often.
Parking brake function is part of rear service too. The shoe assembly sits in the backing plate, so inspection means checking lining wear and the adjuster through the access area without removing the housing. Park brake cables should move freely through their full travel and should not stick at either end.
- Check the rotor for scoring and runout
- Look for pad wear on both sides
- Inspect caliper seals for leaks
- Test parking brake hold on a slope
- Replace cables that stick or fray
Specifications
| Brand | Baer Brakes |
|---|---|
| Part number | 4302332S |
| UPC | 844165028710 |
| Caliper | S4, 4-piston, fixed |
| Caliper color | Silver |
| Rotor outside diameter | 12.0 inch |
| Rotor thickness | 1.02 |
| Rotor type and surface | 1-piece, vented, slotted, drilled, zinc plated |
| Rotor material | Iron |
| Axle flange | GM small pattern 10/12 bolt, bearing on axle (Buick/Olds/Pontiac) |
| Wheel bolt pattern | 5×4.75 / 5×5.00 inch |
| Lug count | 5 lug |
| Minimum wheel diameter | 16.0 inch |
| Pad FMSI number | DR1-C |
| Hose material | Steel braided, DOT approved |
| Park brake | Included |
| Park brake cables | Not included |
| Emission code | 6 |
| Template | S113E |
| Country of origin | US |
Vehicle fitment
The kit is built for GM small pattern 10/12 bolt, bearing on axle rear ends, the flange used on Buick, Olds and Pontiac applications. Match your housing flange and 5×4.75 or 5×5 bolt pattern before ordering.
Wheel style can affect fit, so check the S113E template against the wheels you plan to run. Confirm your vehicle’s year, model and trim before ordering.
Installation notes
Park brake cables are not included, so plan on reusing or sourcing cables that suit the included park brake shoe assembly. Lug nuts and the front rotor are also not included. Work on bearing-on-axle housings is best left to a shop experienced with GM rear axles.
What’s included
Per the kit contents: S4 rear caliper with backing plate and park brake shoe assembly, 12.0 inch rotor, and braided brake hoses.
Not included: park brake cables, lug nuts, front rotor.
