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I have a 1998 Mercury Marquis with Anti Lock Brakes. My question is, “When I replace the front brake pads on this car should I open bleeder valve, before I press the piston back to allow for the new pads? Or should I just empty the brake master cylinder and let the fluid come back into the Master Cylinder when I install new brake pads.

If all you are going to do is change brake pads, then open the bleeder screw BEFORE pushing the piston back. Never push “old nasty brake fluid” back into the Brake Master Cylinder. If you do, you may damage the Anti-Lock Brake components and/or the master cylinder. Brake fluid is only good for about 2 to 3 years and needs to be changed like the other fluids on your vehicle. Brake fluid is hygroscopic and will “absorb moisture” over a period of time. When brake fluid becomes moisture laden brake calipers can get sticky from rust and debris. Brake wheel cylinders can leak and or stick allowing your brake pedal to drop to the floor in a “panic stop” By doing a brake job correctly the “first time” you are saving money in the long run. Your cars brakes will last twice as long because they are not constantly dragging against the brake rotors. When they drag against the rotors you pay at the gas pumps in loss of fuel mileage. If you want the brakes to last longer, make NO noise and not "drag" causing you fuel mileage to suffer. Then replace the cars brake calipers with “Factory Rebuilt Loaded Calipers” By doing the brakes this way will insure a brake job that should last as long as the original brake job from the manufacture. If you do change the calipers try this brake bleeding “Tip” to make sure that you don’t have any brake bleeding problems later on. 1) After you have changed one front brake caliper, then bleed that caliper BEFORE you proceed to the other side. 2) Bleed this caliper until clean brake fluid comes out the bleeder screw. 3) Repeat this process when you change the other brake caliper. By bleeding the calipers as you change them you minimize the chance of running the master cylinder dry. The only thing I have not covered is changing the brake rotors or turning them to make sure that the disc pads make full contact with the rotors. If you do decide to replace the rotors with new ones make sure that you wash them with hot soapy water to remove the protectorate from the rotors BEFORE you install them. If you decide to cut the rotors instead of replacing them, wash them with hot soapy water to remove the particles of metal from the surface of the rotors. If not, the brakes will make noise in the near future when you come to a slow speed stop. Like the sound of fingernails across a blackboard!

 

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