A couple weeks after installing my dual-piston SUV rear calipers with Baer 14" drilled/slotted rotors, I noticed a hollow moan/grinding sound when coming to a stop. I only notice it when under about 15 mph. If I'm very light on the pedal it won't make the noise. Any more pressure and it will. I'm using Wagner theromoquiet ceramic pads.

I called Baer and they think it might be a resonance issue, and that some vehicles have extra brackets and counter weights to stop this. Anyone heard about this for our vehicles? Anyone had a similar issue?

Everything is tight, backing plates were ground down to clear the brackets. I took them apart a couple days ago and everything looked great, but it still makes the noise.

Thanks!

 

With slotted rotors a humming/slight vibration is normal when the rotors get hot. In a heavy truck it does not take much for the brakes to get hot.

 

I've never had excess noise from drilled/slotted rotors in the past. The front rotors are the same as the rear, same pads, and are dead quiet.

 

Could it be the dust shield, and you only here it when driving slow?

 

Ok, just sharing my experience...

 

Baer said it could be the shield resonating, but it's not touching anything it shouldn't be. I had a buddy brake from 50 to 0 while I was in the bed with my head hanging over to listen, and it only starts making noise when under 20-15mph and keep making noise still near stopped. Very peculiar.

 

First of all, it is dangerous to ride in the bed of a truck at any speed not to mention Illegal in alot of states...

As to your problem the rotors, you could have minor distortion. When they have minor distortion it pushes the pad in out and can cause a harmonic effect. You wont always feel the pulse in the pedal if the distortion is minor.

I am not sure about your specific conversion but make sure you have sufficient clearance around your shield like 1/8 of an inch to insure the bracket is not moving/ flexing and hitting the plate ever so slightly.

I am not a big fan of those pads either. I started using the Centric Posi Queit's . Also, I always use the recommended OEM pad material. I have noticed for example if you use Ceramics were a Semi-Metalic was specified or vise versa you could have Noise issues.


HTH

 

Thanks for your thoughts. The first thing I may to is try another pad, although Baer made no mention of the pads being the potential issue. They recommended using ceramic. As for riding in the bed, it was on a closed course, wide open, flat paved area, no real danger, IMO

 

Expect flying out with nothing to hold you in... LOL

If that's what they recommended then they should know after all it is there rotor. Maybe try another brand or If you have access to a shop have some one check your rotor run out...