what why cause dust cover shield rub rotor replace new install? grind squeal noise?

[rogerranger2122]

sorry for title, I wanted to put many key words to help anyone else trying to figure this out.

I read many threads people had this happen but no real explanation as to why.
Are new rotors sometimes thicker than OEM? I know break pads don't contact or wear down the outer rim of the rotors where mine is now rubbing, so it's not that but maybe these rotors are like 1/4" thicker than the previous?

I've read threads of people who seem to know a lot about mechanics and installed $500 higher quality rotors and get this problem.

I changed pads and rotors on a 2006 Honda pilot for my sister. About a week later she says there's some sort of leak and bad grinding noise.Turns out the leak was just normal air conditioner drip lol.

I changed pads + rotors like 8 times no problem on various cars, so I didn't want to open up the wheels to check but the thing I noticed that made me open the wheels was the wear indicator tab on the brake pads - I never really gave much thought as to which side of rotor to put that tab but this time I googled and they say to make it so the rotor spins in a way that the tab is ahead of the pad. So as you know the caliper's inside section is the piston and only that piston seats against the back of the inner brake pad. And the outer section of the caliper (towards lug nuts) is sort of a C shape. Well I noticed the C shape side of the caliper (which is where I put the wear indicator) pinches the wear indicator (on some vehicles) because the indicator tab is sometimes secured to the pad in a way that when you install that C side of the caliper only one side of the C is seated against the wear indicator and thus the pad is sort of seated on an angle - so I took the wheels apart to put the wear indicator on the inner side of rotors in case this was causing the noise. As I'm putting it back together I notice the grinding sound that started all this. Then discover it's the rotors rubbing on the dust shield, so I just bent the dust shield back a bit.


But WHY does this happen if not that the new rotors are a bit thicker? When I took the old rotors off, I banged them with a mallet to get them unstuck but even that shouldn't cause the rotor to tilt back and bend the dust cover, and even if it did, the dust cover is bent towards the rotors, not away.

 

[Bill]

New rotors should have the same specifications as OEM rotors. Stick with the main brands (Centric, etc) and you shouldn't have a problem with the rotors unless you have the wrong rotors. As for the dust cover rubbing on the rotor, a bent dust cover is the only thing I can think of. You may have bent it using a mallet to the the rotor off, which sounds kind of strange. Another possibility is it was bent prior to replacing the rotors, but the old rotors had enough wear on them to give the dust cover enough clearance. Just bend the dust cover back and it should resolve the problem.

 

[Ranger850]

^^^^YES, THIS^^^. Sometimes ppl add pads to old rotors, so the thickness is NOT OEM specs. This could have been when the dust cover was bent. Then when you put on NEW pads and rotors, it is back to OEM specs, and the dust cover is now too close, causing the rub.

 

[Snoranger]

New rotors should have the same specifications as OEM rotors. Stick with the main brands (Centric, etc) and you shouldn't have a problem with the rotors unless you have the wrong rotors. As for the dust cover rubbing on the rotor, a bent dust cover is the only thing I can think of. You may have bent it using a mallet to the the rotor off, which sounds kind of strange. Another possibility is it was bent prior to replacing the rotors, but the old rotors had enough wear on them to give the dust cover enough clearance. Just bend the dust cover back and it should resolve the problem.

We use Centric rotors at work. Everyone one of them runs on the backing plate on the rear of our fleet of F250-350s. 75+ brake jobs... every single one, same issue, same spot. We just grind 1/4" off the couple of spots on the backing plates before assembling.

 

[Bill]

We use Centric rotors at work. Everyone one of them runs on the backing plate on the rear of our fleet of F250-350s. 75+ brake jobs... every single one, same issue, same spot. We just grind 1/4" off the couple of spots on the backing plates before assembling.

Where do they rub?

 

[Snoranger]

Where do they rub?

The ring around the parking brake drum.

 

[Bill]

The ring around the parking brake drum.

Are you talking about rotors or drums? I'm not familiar with the F250.

 

[G8orFord]

He's kinda talking about both. The rear rotors also have a "drum" for the parking brake.