2G Grinding sound when braking - only after 15 mins of driving

[Spades]

Ive got a grinding sound during braking, but it only happens after at least about 15 mins of driving and never before that. I was thinking the CV axle so i replaced the driver side because i found a torn inner boot, but didnt make a difference, grinding noise is still there. I recently installed new brake pads, but the grinding started about a week after the install. Any ideas or suggestions? I cant think of any component that would only start to make a grinding sound after about 15 mins of driving. First 10 mins of driving, the brakes are perfect

 

[AWD-Tony]

It's going to be hard to tell you what going on through the interwebs. Best thing you can do is get it hot, put it up on jack stands safely, and see if you can replicate the noise with someone controlling the gas and brakes.

 

[silvreclips]

Since it started after you changed the brakes, and only makes the noise when on the brakes. I would be start looking there. Try to figure out which side it's coming from and take it back apart. Make sure you put everything back together correctly, maybe you mixed up the slide pins, or didn't put enough grease on them.

 

[delta448]

Did you reuse the old pad shims? Rusty ones can cause the pad to hang up at an angle in the bracket. Look for a scored grove in the rotor.

 

[Spades]

I dont recall any shims during the assembly. But wouldnt that grind all the time if it was at an angle, and not just after 10-15 mins of driving?

 

[delta448]

When the brakes heat up, things expand. That whole area can become very hot. If the pads aren't kept in place with a good set of well lubed shims, all sorts of stuff can happen. Worst case scenario the pads wear incorrectly and cut into the rotor and cause a safety concern. Can you snap a couple of pictures?

 

[AWD-Tony]

Expansion takes place anytime heat gets involved. You should pick up a shim kit and install it. Make sure to apply proper lube and clean off where the shims are installed.

 

[BLACK'98DSM]

I dont recall any shims during the assembly.

What? So you did not use shims for your brake shoes? I'm a little confused at this.

EDIT: So you just didn't change them.

 

[Spades]

Ok i took a look yesterday, and yes the shims are there. After doing many brake jobs in the past on various cars, i tend to forget the lesser things in the assembly. Plus getting older... So, my plan of attack from here is to get the car hot and immediately jack up the car and rotate, wobble, rock the assembly while someone lightly steps on the brakes and see if i can find anything. At this point i am leaning toward wheel bearing

 

[delta448]

Very possible. In my experience though, the wheel bearings make noise all the time when bad, they can even make a howling noise at speed, not just when braking.

 

[TerminalTalon]

Raise the car up on all 4’s in neutral and rotate the wheels. There shouldn’t be that much different is force applied but if there is look at that wheel. Caliper slide pins stick, pistons get frozen and hoses deteriorate. That is if it’s brake related.

 

[TerminalTalon]

Wheels bearings tend to make noise while going straight of one direction in a turn. Drive down the road and turn into the other lane. Does the noise go away? Turn back. Did the noise go away? One of those will tell you. Tires will just make noise all of the time.