Hi all,

I have spent the week troubleshooting my girlfriends car. I am not familiar with this car as I drive an older F-150, so any input is appreciated.

A loud grinding noise began whenever she would break abruptly. It has since evolved into a noise that generally occurs at lower speeds and when she's coming to a full stop, such as pulling into a parking space. In my experience, such a grinding noise is a sign of bad pad deterioration. I replaced the front pads, since the noise was coming from the front passenger side. I inspected and measured the rotors, they are in good condition (about a year old) and have little to no wear. In addition, I discovered that the passenger side caliper had one seized piston. I replaced this caliper and it now functions correctly. I also bled the brake.

However, despite driving perfect for a few days as if fixed, the grinding sound is back. It makes the grinding noise intermittently when braking, especially at slow speeds for whatever reason. looked up videos to see if I could find a similar sound, and I came across this one. This is exactly the sound that it makes.
I think there could be a problem with the abs system? One additional symptom is that the front passenger side wheel has an abnormal amount of brake dust that is not present on any of the other wheels, which obviously seems like some metal on metal contact is occurring, despite good rotors, new pads, and new caliper.

Has anyone experienced this or have any insight?

 

I couldn't watch the vid. The guy talks too much.

How bad were the pads when you replaced them? You should probably check out the ABS sensor and sensor ring on the passenger side. The sensor ring looks like a square toothed gear and rides just behind the hub . If the wheel is cracked or the sensor is not attached correctly/misaligned, it could be causing your brakes to drag or act weird when you hit them.

The third picture down under BRAKE SYSTEM OVERVIEW will show you what the sensor wheel looks like. The sensor will be positioned just over the top of it although maybe not in the same position as the photo. That looks like a SN 95 Mustang.
https://www.americanmuscle.com/brake...ech-guide.html

 

If splash-pan type guards are behind the rotors, check carefully for one or more tiny stones of gravel trapped between one and the rotor. They will grind like hell then stop as braking effort changes.

 

Brake dust on the one wheel would indicate a drag on the pads. I would be looking at the wheel bearing or that new caliper isn't releasing. Another thing is the flex brake hose maybe collapsing thus stopping the caliper release.

 

I was thinking along the lines of the rotors themselves.

 

^This! Also make sure the calipers are mounted correctly with new sliding pins.

 

The pads were reasonably worn. They pads on the passenger side (where the noise comes from) were worse than the drivers side.

Those pictures you provided are helpful. I can see the ring and sensor, but what am I looking for? It looks fine, but I have no way of testing it.

In the meantime, I checked the wheel for play. The passenger side outer tie rod is shot and making noise in a 9-3 position. This is only on the passenger side. I ordered new inner and outer tie rods for both sides and will replace, but I don't think that has anything to do with it, unless you all know something I don't.

 

Caliper is functioning correctly. I did change and lubricate the new sliding pins.

How can I test the wheel bearing?

 

Rotors are about two years old, I measured them with a micrometer and they seemed to be well within operating spec. There is also no visible sign of damage.

 

How bad ARE those brake pads? Checking the wheel bearings,standard way is grab the tire at top and bottom while jacked off the ground, and see if there is play. On gthese newer type module wheel bearings(bolt on unit) I have found you can also take off the tire and rotate the HUB slowly,listening for clicking and feeling for roughness.