Table of Contents
Safety First
Before you lift a vehicle, make sure the car is on a flat surface, the parking brake is engaged, and wheel chocks are placed behind the rear wheels. Use a floor jack to lift the front of the car and secure it with two sturdy jack stands. A Cadillac’s front brake flex hose sits behind the wheel, so you’ll need to remove the wheel to access it. Keep a 19‑mm wrench handy for the lug nuts and a 10‑mm wrench for the bleeder screws.
Removing the Wheel and Preparing the System
With the car safely supported, use the 19‑mm wrench to loosen and remove all five lug nuts on the front wheel. Set the wheel aside on a flat surface. Once the wheel is off, you can see the flex hose that runs from the master cylinder to the caliper. Inspect the hose for obvious cracks or bulges before proceeding.
Bleeding the Brakes Before Disconnecting
To keep air from entering the system, open the bleeder screw on the caliper with an 11‑mm wrench and place a collection receptacle over it. While the brake pedal is pressed to the floor, hold it with a pry bar or a piece of wood. This forces fluid out of the hose and caliper, preventing a sudden loss of pressure when you later disconnect the hose. Keep the receptacle in place until the fluid stops dripping.
Disconnecting the Flex Hose
Move the receptacle under the hose’s connection to the caliper. As you unscrew the banjo bolt, fluid will escape; collect it in the receptacle. Inspect the banjo bolt for wear or damage and set it aside. To keep the hose from dangling and dripping, leave the bolt slightly loose and follow the hose to the bracket that attaches it to the vehicle body. Use a small pair of pliers to remove the metal clip that holds the hose in place.
Preparing the New Hose and Mounting Bracket
Clean the mounting area with a rag, checking that the bracket, hose fittings, and any retaining clips are free of rust or damage. The flex hose has a circular port with two notched tabs that must line up with corresponding slots in the bracket. Align the larger tab first, then the smaller one, and slide the hose into the bracket. A metal locking clip secures the hose; press it in so the angled tab faces toward the brake line, not outward. Verify that the hose sits flush against the bracket and that the clip is fully seated.
Installing the Banjo Bolt and Gasket
Insert a new gasket between the hose and the caliper flange. Slide the banjo bolt through the gasket and tighten it to 37 ft‑lb with an 11‑mm wrench. Make sure the hose does not move when you apply pressure; any play could cause a leak. Check that the banjo bolt threads are clean and that the gasket is not crushed or misshapen.
Final Bleeding and Reassembly
With the new hose in place, perform a gravity bleed. Remove the brake pedal depressor, open the master cylinder cap, and allow fluid to flow out of the bleeder screw. You should see a steady stream of clear fluid with no air bubbles. Once the fluid runs clear, replace the cap and bleed the remaining wheels in the order: passenger rear, driver front, driver rear, passenger front. After each wheel, pump the brake pedal until it feels firm, then check for leaks. If any wheel still shows air bubbles, repeat the bleed until the fluid is clear.
Finishing Touches
Top off the master cylinder with DOT 3 or DOT 4 brake fluid, reinstall the bleeder screw covers, and tighten all wheel lug nuts to 100 ft‑lb in a criss‑cross pattern. Because brake fluid is corrosive, wipe the area around the master cylinder and replace any damaged seals. Place a protective barrier between the master cylinder and the vehicle paint to prevent future corrosion. The job is complete when the brakes feel firm, the pedal has no sponginess, and no fluid leaks are visible.