About every six months, with the vehicle raised and securely supported on jackstands, inspect the rubber hoses connecting the steel brake lines to the front and rear brake assemblies for cracks, chafing, leaks, blisters, and other damage, as these are crucial parts of the brake system. Use a light and mirror for a thorough check, and replace any damaged hose with a new one. To replace the front brake hose, disconnect the brake line from the hose fitting using a back-up wrench, ensuring not to bend the frame bracket or brake line. Remove the U-clip from the female fitting at the bracket and detach the hose, then unscrew the brake hose from the caliper, removing the bolt and copper washers. Install the new hose by connecting it to the caliper with new copper washers, lubricating the inlet fitting bolt threads with clean brake fluid, and tightening the fitting bolt to the specified torque. Install the female fitting in the hose bracket without twisting the hose, secure it with the U-clip, and attach the brake line to the hose fitting, ensuring no kinks in the hose and that it does not contact any suspension parts. For the rear brake hose, disconnect it at the frame bracket, remove the U-clip, and separate the female fitting. Disconnect the hydraulic lines at the junction block, unbolt, and remove the hose, then bolt the junction block to the axle housing and connect the lines securely. Install the female end of the hose in the frame bracket, secure it with U-clips, and attach the steel line fittings carefully. Ensure the frame bracket remains tight, fill the master cylinder reservoir, and bleed the system. When replacing brake lines, use the correct steel parts and avoid copper tubing. Prefabricated brake lines with flared ends and installed fittings are available, and if bending is necessary, use a tube bender without crimping or damaging the line. Ensure the new line is securely supported and has clearance from moving or hot components, check the master cylinder fluid level after installation, and bleed the brake system before testing the brakes carefully.
Posted by GMPartsGiant Specialist 
