Loud vibration coming from front brake shoe or caliper when i am on rough road but on smooth surface no noise

If a hub bearing was bad, it almost always would make noise, more so when changing lanes at higher speed. Outer CV joints make a loud low pitched rattle when turning (corners). Inner CV joints raise hell at high speed- bad shake! Sway links affect cornering and clunk when hitting rough patches of road surface.
Is the vibration worse at 65 than at 50? If so, you are dealing with a wheel balance situation. Find an old time front end shop that will check the balance on the vehicle. You will have to turn off the traction control to do this or use an on-the-car wheel balancer.
If you feel it at some low speeds at it comes back at other higher speeds, then you are dealing with tire roundness. Possible more than 1. More common than we would like.

This is one of them questions and need i say more ,as without looking myself and having a drive then i could tell you straight away iam sure ,because without hearing the noise i cannot even summise where or what it is because a grinding noise is -well -difficult to denominate exacty what one defines as a grinding noise ,myself i would define it as a rythmic noise with the road speed but someone else would call it that noise for a trailing arm bush loose or worn but one thing to check is are the pads hitting a part of the brake disk thats corroded like on the edge of the brake disk ,sorry to be absolutely no help at all but i hope you appreciate how difficult it is to diagnose something with hearing it and from afar ,but if you only hear the noise when on a rough road could it be the tyres like a deformed tyre or them town and country tyres with big chunky treads .

Chances are the calipers are not at fault.You probably live in a northern state that puts salt on the roads in the winter time. Take a close look at the brake shoes. and where they mount. Often the manufacturer will put a thin metal plate over a caste iron iron caliper/brake pad mount. This is to give the brake pads a smooth surface to slide on. Take the the thin metal plates off of the bracket and file off the rust under neath the plates. The rust is expanding and pushing against the back of the thin plates causing the brake pads to bind and stick. This is then overheating the caliper and ruining it. Take a file and remove all the rust on the mounting brackets especially under the the brake pad slide plates. Once the brake pads move freely again the problem should go away.

Different product and different brand the best for you money without the brake dust is carbon metallic,basically you got a low end brand

are you talking about both front brakes sticking.by lines i assume you mean the brake flex hoses.have you checked to make sure that the sliding surfaces are smooth and free of damaged surfaces and the brake pad clips are in the proper places.if so and all this is good that you have done then you could have a master cylinder that is not releasing pressure for the front brakes,or you could have a defective flex hose(if they are not twisted) that is blocking the fluid from releasing the calipers.

Sounds like a brake caliper getting hung up.

Did you have the rotors turned? Did you check for rotor runout? Did you remove all rust from hub face and rotor mounting surface? Did you remove rust from caliper or pad slides? Lube all caliper and pad sliding surfaces? Are the pads application specific? Did you flush and bleed the fluid? Did you torque the wheels properly?

1999 Taurus/Sable Section 06-03: Brakes, Front Disc 1999 Taurus/Sable Workshop Manual REMOVAL AND INSTALLATION Procedure revision date: 06/25/1998 Disc Removal

1. Raise vehicle on hoist.
   

1. Remove wheel and tire assembly. Be careful to avoid damage or interference with caliper bleeder screw fitting and front disc brake rotor shield (2K004).
   

1. CAUTION: Handle front disc brake rotor (1125) and disc brake caliper (2B120) assembly in such a way as to prevent deformation of front disc brake rotor , and nicking, scratching or contamination of brake linings/rotor surfaces.
   NOTE: To prevent damage, do not allow disc brake caliper to hang by the front brake hose (2078) .
   
   
   Remove caliper anchor plate bolts and discard. Position disc brake caliper out of the way. Prevent separation of caliper housing from anchor bracket because contamination of guide pin journals can occur.
   

1. NOTE: If excessive force must be used during front disc brake rotor removal, the front disc brake rotor should be checked for runout prior to installation.
   
   
   If additional force is required to remove front disc brake rotor , apply Rust Penetrant and Inhibitor F2AZ-19A501-A or equivalent meeting Ford specification ESR-M99C56-A on front and rear rotor/hub mating surfaces. First, strike front disc brake rotor between lug bolts (1107) with a plastic hammer. If this does not work, attach 2-3 Jaw Puller 205-D027 (D80L-1013-A) or equivalent and remove front disc brake rotor . Remove front disc brake rotor from wheel hub (1104) assembly by pulling it off the lug bolts.
   

Installation

1. If original front disc brake rotor is being installed, make sure rotor braking and mounting surfaces are clean.
   

1. CAUTION: Failure to clean rust and foreign material from rotor and hub mounting faces when installing new or old front disc brake rotors will result in high rotor runout, which will speed up the development of brake roughness shudder vibration.
   Apply a small amount of Silicone Brake Caliper Grease and Dielectric Compound D7AZ-19A331-A or equivalent meeting Ford specification ESE-M1C171-A to pilot diameter of front disc brake rotor.
   

1. Install front disc brake rotor on wheel hub assembly.
   

1. Install disc brake caliper and new caliper anchor bracket bolts on front disc brake rotor . Tighten caliper anchor bracket bolts to 88-118 Nm (65-87 lb-ft).
   

1. CAUTION: Failure to tighten lug nuts (1012) in a star pattern may result in high rotor runout, which will speed up the development of brake roughness, shudder and vibration.
   Install wheel and tire assembly on vehicle. Tighten lug nuts to 115-142 Nm (85-104 lb-ft) using Rotunda Accutorq® Lug Nut Socket 164-R0303 or equivalent on a 1/2 inch air impact wrench, or use a torque wrench.
   

1. Lower vehicle.
   

1. Pump brake pedal prior to moving vehicle to position brake linings.
   

1. Road test vehicle.
   

it is the u joints on the front drive shaft ,i had the same problem and like too never found it!!!

just checked this out a while ago:



Wheel Hub Assemblies: Systems and Diagnosis of Worn Hub Assemblies & Bearings
Front wheel hub assemblies and bearings control the position of, and reduce the resistance of, vehicle wheels in contact with the pavement. When they fail, front wheels may not be kept in position and vibration and noise usually develop. Symptoms that normally develop as a result of these worn parts include:

• A humming, rumbling or growling noise which increases with acceleration or as the vehicles turns
• Vibration felt in the steering wheel, which changes with vehicle speed or as the vehicle turns
• Looseness or excessive play in the steering wheel (especially while driving over rough road surfaces)
• A loud, constant grinding noise when driving the vehicle (heard in the most severe cases of a wheel bearing failure)
• Pulling to one side when braking.
• Roughness - with the vehicle of the ground, roughness or vibration when rotating the wheel
• Looseness - with the vehicle off the ground, looseness when wiggling the wheel back and forth (Looseness may also indicate a worn ball joint)
• Excessive brake pedal play can also indicate sloppy or excessively loose wheel bearings
• ABS failure in the system may be related to failure of the ABS sensor in the hub assembly or the internal sensor in the wheel bearing