ACDelco 18A1312B Silver Non-Coated Rear Disc Brake Rotor

The ACDelco 18A1312B is an ACDelco Silver series non-coated rear disc brake rotor designed as a quality, high-value replacement for a wide range of GM and non-GM vehicles. Backed by General Motors, this rotor delivers reliable stopping performance at an economical price point.

This is a vented, drum-in-hat style rotor constructed from cast iron with a non-directional ground brake surface finish. The 5-lug design features a 4.5-inch bolt circle (114.3mm) and a 2.5-inch center bore diameter, with an outside diameter of 12.33 inches and a nominal thickness of 0.435 inches.

Key Features:

• ACDelco Silver Series — quality high-value alternative for GM and most other makes and models, backed by General Motors
• Non-directional ground finish — minimizes rotor thickness variation and helps extend brake pad life
• Vented rotor design — application-specific vane configuration maximizes airflow for cooler operating temperatures
• Mill-balanced construction — ensures proper rotor function with no additional balancing weights required
• Manufactured with multiple alloys — engineered for improved heat dissipation and braking performance
• Drum-in-hat design — integrates parking brake drum functionality into the rear rotor
• Full cast iron construction — durable, long-lasting material proven in OE brake applications
• Quality validated — verified for proper metallurgy and correct brake plate thickness

The ACDelco 18A1312B installs as a direct replacement with no machining required. This part may also be referenced by OEM part number 19287368. Note: Some ACDelco Silver parts may have formerly appeared under the ACDelco Advantage name.