97 4.0 ext. As the title says the right front pads wear more than the drivers side. Have replaced calipers pads and rotors during recent overhaul. Noticed increased brake dust on wheel on rf front. Could the metering vlve under masterncyl be the culprid. Abs and brake lights work as normal.

 

How 'bout the brake hose?

 

The 1992-and-later Aerostars came with directional rotors from the factory that helped braking power. If you installed a non-directional rotor, or worse, a directional rotor on the wrong side, it could cause increased heat and wear on that side.

Failing that, check the pistons on each caliper for free movement. Pull off the calipers and gently apply the brakes and see if the pistons on each push out evenly.

 

what xl4 said above...

the Aero brakes are prone to caliper heat damage...kills the syn. rubber protection boot and the inner seal...also lots of water leakage into C. piston with resulting corrosion....the OEM plastic C. piston is garbage and fails often under high temps. cracks and sticks
I replaced mine with upgrade steel pistons and new calipers years ago.

caliper sliders sticking....grooves in caliper or caliper mount are corroded, rusted and/or dirty....used old stainless steel slider pins- a big NO NO, ALWAYS replace the pins with new....
not enough hi temp brake component grease on pins.

flex brake hose broken down on inside with broken off particles preventing drain back of brake fluid from caliper after brake pedal release....these are a wear age replacement item....

metering valve and M. cylinder are common to left and right side front brakes....both sides affected equally.

 

agree with xlt4wd90 and 96_4wdr above; there's a left and a right rotor. And it sounds like a sticking caliper, i.e., the pad is rubbing against the rotor constantly.