Overview
Baer Brakes’ S4 front disc brake system, part 4301438S, is a silver four-piston kit that arrives on stock-height spindles. It fits 1978 to 1988 GM G-Body cars and 1982 to 2004 S10 and S15 pickups, and the S10 and S15 Blazer and Jimmy 2WD models from the same era.
The 11 inch two-piece rotor and S4 caliper come from the SS4 Plus line, a smaller version of Baer’s larger systems made for wheels 15 inch or larger. Each hub is assembled with bearings, and the rotor is pre-assembled with stainless hardware.
Key features
- Silver powder coated S4 four-piston caliper formed by CNC machining forged or billet aluminum
- Hard anodized aluminum pistons with stainless steel abutments
- Dual dust, weather and pressure seals
- Two-piece slotted, drilled, zinc plated rotor with an aluminum hat
- Rotors pre-assembled with NAS high grade stainless hardware
- Billet aluminum hubs with premium bearings and billet dust caps
- Stainless braided steel brake hoses, DOT approved
- Uses FMSI DR1 pads, and HB100 is also an accepted pad type.
Before you buy
Front disc brakes do most of the stopping on a light truck or G-body, so the rotors, calipers and pads work as one system. When the pads wear, the rotor surface can glaze, groove or lose thickness, and a worn rotor reduces braking feel even with fresh pads. Checking thickness and surface condition at each pad change helps catch problems early.
Slotted and drilled rotors help clear debris and gases from the pad face, which can matter on trails, while towing and during repeated hard stops. Pad compound should match how the vehicle is used. A softer pad bites quickly but wears faster, while a harder pad suits mostly street driving. Bed in new pads and rotors gradually to transfer an even layer of material.
Hose condition is worth checking when the front end is opened up. Braided lines resist swelling better than rubber, but they still need inspection for chafing at brackets. Brake fluid absorbs moisture over time, so flushing it on a regular schedule keeps the calipers working correctly. Re-check lug nut torque after the first few drives on new wheels.
- Look for scoring, blue spots or cracks on the rotor face
- Replace pads before the backing plate contacts the rotor
- Inspect hoses for chafing, bulges or leaks at fittings
Specifications
| Brand | Baer Brakes |
|---|---|
| Part number | 4301438S |
| UPC | 844165030690 |
| Caliper | S4, four-piston, fixed, silver |
| Rotor | 11.0 inch, two-piece, vented, slotted and drilled, zinc plated |
| Rotor material | Iron with aluminum hat |
| Rotor thickness | 1.02 inch |
| Pad type (FMSI) | DR1 |
| Axle and drive | Front, 2WD |
| Minimum wheel diameter | 15.0 inch |
| Bolt pattern | 5 lug, 5 x 4.75 inch |
| Wheel stud size | M12-1.50 x 51.5mm |
| Spindles included | Yes, stock height |
| Template | S125A |
| Brake hose | Steel braided, DOT approved |
| Lug nuts included | No |
| Country of origin | US |
Vehicle fitment
It fits 1978-1988 Buick Regal; 1978-1987 Chevrolet El Camino; 1978-1983 Chevrolet Malibu; 1978-1988 Chevrolet Monte Carlo; 1982-2003 Chevrolet S10; 1983-1994 Chevrolet S10 Blazer; 1982-1990 GMC S15; 1983-1991 GMC S15 Jimmy; 1978-1981 and 1985-1988 Oldsmobile Cutlass; 1978-1988 Oldsmobile Cutlass Supreme; and 1978-1988 Pontiac Grand Prix.
The list starts in 1978, so earlier G-body cars are not covered. Four-wheel-drive S10 and S15 models fall outside this 2WD kit. Confirm your vehicle’s year, model and trim before ordering.
Installation notes
Because the spindles come with the kit, the front end is set up with the spindles, hubs and rotors already matched. Rotors come pre-assembled with stainless hardware, and braided hoses and mounting brackets are included. Lug nuts are not supplied, and the M12-1.50 studs on the 5 x 4.75 inch pattern need lug nuts made for that thread size. Raise the front end on jack stands before removing any wheel.
What’s included
Silver S4 calipers, 11 inch two-piece rotors, billet aluminum hubs with bearings and dust caps, stock-height spindles, mounting brackets, stainless braided hoses and hardware.
Not included: Lug nuts.
