GM 20795300
Rotor, Front Driver Side

Before starting to replace j56 front Brake Disc, check the brake master cylinder reservoir fluid level to ensure it sits between the marks. Drain off fluid until the level reaches the halfway point. Place the vehicle on jack stands and take off the tire and wheel components from the vehicle. To install a new Brake Disc keep it properly aligned with the wheel hub based on your matching marks. Secure the brake caliper with thick mechanic wire after releasing its bolts so the hydraulic brake hose stays safe. Take away the Brake Disc screw and the Brake Disc in this order. Clean dust and rust using wheel hub and disc resurfacing tools including the j-42450-a and j-41013 products. Place the disc on its mounting position and line up its match mark before fastening the disc screw to 14 nm (24 lb in). Before installing the brake caliper check both its mounting threads and the knuckle holes for cleanliness. Use threadlocker gm p/n 12345493 to apply on 2/3 of the threaded bolt area before letting it cure for 10 minutes. Secure the brake caliper bolts using torque setting at 175 nm which equals 129lb.ft. Take measurements to assess how the Brake Disc performs laterally after installation into the repaired system. Replace the Brake Disc when the readings show unwanted results. When done install the wheel and tire while following standard procedure for pad and disc burnishing if replacement parts were used.

Detach the brake caliper bracket bolts and support the brake caliper with heavy mechanic wire to prevent damage to the hydraulic flexible brake hose.

Detach the brake caliper bracket bolts and support the brake caliper with heavy mechanic wire to prevent damage to the hydraulic flexible brake hose.