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Q: Brake pad replacement - Front & Rear

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When the onboard diagnostics alert that the brake pads need to be replaced, is it necessary to replace the entire brake/disc unit or pads only? Also, is a brake line flush necessary at this mileage interval?

I think my wife is being given the XX upsell. Located in Houston. Thanks in advance.

My car has 32000 miles.
My car has an automatic transmission.

A: If your vehicle uses DOT 5 (silicone-based)...

If your vehicle uses DOT 5 (silicone-based) fluid, the flush interval is much, much longer than 2 years or 32,000 miles. However, if your vehicle uses glycol based fluid, it should be thoroughly removed from the brake system roughly every 4 years, the more frequent the better. Glycol based brake fluids are highly hygroscopic and the resulting, that is inevitable, moisture contamination has the potential to cause lots of problems with braking systems such as corrosion, entrained gas, and so forth. If brake fluid is added to your vehicle, be sure the shop knows how to read instructions: the EXACT type of fluid specified for your vehicle must be used to top off.

As the caliper piston is pushed in to create room for the new pads, the fluid should be bled from the bleeder screw on the caliper, not forced back into the master cylinder. Also, the level of fluid at the brake master cylinder reservoir must be confirmed before you leave the shop. If you replace brake pads, the rotors absolutely MUST be measured and turned (even if only little resurfacing is required) or discarded and replaced with new ones.

If they suggest re-using the old rotors as is because they "look good", or without careful measurement and verification, that means that they do not understand that if there is .002 inches (one half the thickness of a hair) of run-out in the rotor, you will get pedal pulsation or if you don't presently have it, you will. It is preferred to use the OEM (dealer) brake pads in your application. The sliding pins on the caliper must be disassembled, cleaned and re-lubricated with high temperature brake grease. To prevent the rotor from being warped on re-application to the hub, they have to use a calibrated torque wrench and tighten the bolts in a sequence. If, at your mention of any of these INSTRUCTIONS, they look at you as if this is the first time they have heard it, it IS the first time they have heard it and they don't do it. If you want it done right, feel free to follow up with YourMechanic and a certified professional will do the job to perfection for you. Any further concerns, please re-contact us.

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