PowerStop L4991J Disc Brake Caliper - Front Left

Front Left OE Replacement Caliper

PowerStop L4991J is a front left disc brake caliper built as an OE stock replacement for select Jeep applications. It is remanufactured to bolt directly in place of the original caliper and uses a floating design with a 48.01 mm piston for factory-style brake service.

Compatible with 2006-2010 Jeep Commander front left and 2005-2010 Jeep Grand Cherokee front left, this caliper is a direct-fit option for drivers replacing a worn or leaking front brake caliper on a Jeep Commander or Jeep Grand Cherokee. The gray finish and included mounting bracket support a straightforward OE-style replacement.

PowerStop OE Replacement Line

The PowerStop Autospecialty OE Replacement Brake Caliper line focuses on stock replacement brake service for budget-conscious repairs. PowerStop remanufactures the caliper and bracket in Chicago, IL, then pressure tests each unit to verify piston operation and check for leaks before release.

• Front left disc brake caliper for OE-style replacement
• Floating caliper design with 2 pistons
• Cast iron caliper body with phenolic piston material
• Includes caliper slides and mounting bracket
• High-temperature EPDM dust boots and silicone lubricant used in assembly
• Bleeder screw thread size: M10 x 1.0

Detailed Product Information

PowerStop L4991J is assembled with new seals, slide pins where applicable, dust boots, bleeder screws, and stainless steel brake pad abutment clips. The caliper is pressure tested for piston movement and leak prevention, and the remanufacturing process is intended to restore consistent hydraulic operation for front brake service on Jeep Commander and Jeep Grand Cherokee models.

Common Repair Reasons

• Leaking front left brake caliper
• Sticking or uneven piston movement
• Corrosion on the original caliper body
• Brake drag or uneven pad wear at the front left wheel
• Loss of braking performance from a worn hydraulic caliper

Installation Notes

Verify front left fitment by year, make, and model before installation. Transfer or replace brake pads and inspect the brake hose, rotor, and hardware condition during service. Bleed the brake system after installation to remove air from the hydraulic circuit and confirm proper pedal feel.

Quality Assurance

Each PowerStop caliper is pressure tested to confirm piston operation and help prevent leaks. The remanufacturing process includes new internal seals and external wear components, along with EPDM rubber dust boots for durability in demanding brake environments.