Help diagnose my brakes

[9c1sheriff]

When applying my brakes and coming to a stop I have been experiencing noise. From about 20mph-10mph the front driver pads give a nice squeak. As I go from about 10mph to a complete stop I can hear and feel a rubbing, somewhat grinding, sensation and sound. But more of a rubbing "grooovvvv" sound.

As of August 2008, I have replaced on both the front and back, new pads, rotors, front bearings/seals, all hardware (pins, bushings, etc.), new rear caliper brackets w/boots and pins, and have used lube on all hardware and contact points.

In the past 8 months (end of spring and beginning of fall) I have cleaned and re-lubed all hardware twice, checked rotors for scratches and marks, pad wear, and fluid level, but all seems good.

This noise has been occurring off and on since around May, but has been much more frequent as of late. It does not happen on every stop, but seems to occur after the car has warmed up and been driven for a few minutes. It does not happen when I cold start the car for the day and drive through the first few stop signs in my neighborhood.

Any ideas? I was thinking sticking caliper, but I have absolutely no pulling on any type of braking scenario. Whether it be a hard or slow stop, the car tracks straight. Also the wheel does not feel any hotter than the other three. I am positive it is coming from the front driver from both the sound and feel in the pedal. That, and driving down the street with my door open and my head hanging out while I come to a stop!

[impalito96]

I know it's off the subject, I noticed you had a 96 9C1 from cook county sheriff's dept. Was that Cook county IL?

Originally Posted by 9c1sheriff

When applying my brakes and coming to a stop I have been experiencing noise. From about 20mph-10mph the front driver pads give a nice squeak. As I go from about 10mph to a complete stop I can hear and feel a rubbing, somewhat grinding, sensation and sound. But more of a rubbing "grooovvvv" sound.

As of August 2008, I have replaced on both the front and back, new pads, rotors, front bearings/seals, all hardware (pins, bushings, etc.), new rear caliper brackets w/boots and pins, and have used lube on all hardware and contact points.

In the past 8 months (end of spring and beginning of fall) I have cleaned and re-lubed all hardware twice, checked rotors for scratches and marks, pad wear, and fluid level, but all seems good.

This noise has been occurring off and on since around May, but has been much more frequent as of late. It does not happen on every stop, but seems to occur after the car has warmed up and been driven for a few minutes. It does not happen when I cold start the car for the day and drive through the first few stop signs in my neighborhood.

Any ideas? I was thinking sticking caliper, but I have absolutely no pulling on any type of braking scenario. Whether it be a hard or slow stop, the car tracks straight. Also the wheel does not feel any hotter than the other three. I am positive it is coming from the front driver from both the sound and feel in the pedal. That, and driving down the street with my door open and my head hanging out while I come to a stop!

[gpasroadmonster]

What kind of pads did you use? If they are Semi's there could be a chunk of metal in that particular pad causing an odd noise.

[9c1sheriff]

Originally Posted by gpasroadmonster

What kind of pads did you use? If they are Semi's there could be a chunk of metal in that particular pad causing an odd noise.

Sorry, I should have specified that. I used Performance Friction Carbon Metallic Pads for both the front and bake. If there was some kind of "chunk" causing the noise, would it not happen all the time?

Originally Posted by impalito96

I know it's off the subject, I noticed you had a 96 9C1 from cook county sheriff's dept. Was that Cook county IL?

Sure was! Lived in Chicagoland my whole life until 3 years ago. Nice car too, except for the salty cancer underneath. Had full cloth tan interior with bench seat in the front. One hole on the trunk lid. Insurance paid me way more than what I paid for it so it all worked out in the end!

[9c1sheriff]

So am I missing something obvious here, or have I stumped everybody?

[gpasroadmonster]

Im stumped

[9c1sheriff]

Still looking for help on this one.

Drove around Saturday and it happened again as the car warmed up. Drove around today and no symptoms.

This intermitent thing is what is confusing the heck out of me.
-Sticking caliper? Car does not pull in any one direction when braking, and no "hot rims".
-pad material? Checked pads and they are clean. Plus, wouldn't rough pads cause the issue all the time?
-Bushings and hardware are new (1 year), lubed, and torqued correctly.

Navy Lifer, you are the brake guru on the forum, any ideas?

[Dilbert 9C1]

What brand of rotor??

I have seen defective rotors where they would cause a noise like you are describing. What happens is that they have a void underneath the friction surface. It usually becomes obvious when they get turned/cut down....

To narrow it down-- switch pads from left to right and see if the noise follows the pad....

[SEO9C1]

Did you bed the pads in initially?

http://www.stoptech.com/tech_info/wp_bedinstock.shtml

If not, try that 1st. Should problem persist:

Originally Posted by Dilbert 9C1

To narrow it down-- switch pads from left to right and see if the noise follows the pad....

Will narrow down whether it's pad or rotor related, but if switched, rebedding will be necessary.

Might want to dab the ABS sensors w/ some hi-temp lube just for shots and goggles.

[9c1sheriff]

Originally Posted by Dilbert 9C1

What brand of rotor??

I have seen defective rotors where they would cause a noise like you are describing. What happens is that they have a void underneath the friction surface. It usually becomes obvious when they get turned/cut down....

To narrow it down-- switch pads from left to right and see if the noise follows the pad....

The rotors are Duralast. I will switch pad sides during the weekend to see if the noise follows.

Originally Posted by SEO9C1

Did you bed the pads in initially?

http://www.stoptech.com/tech_info/wp_bedinstock.shtml

If not, try that 1st. Should problem persist:


Will narrow down whether it's pad or rotor related, but if switched, rebedding will be necessary.

Might want to dab the ABS sensors w/ some hi-temp lube just for shots and goggles.

Yes, the pads were bed when installed. I even re-bedded them last month, during which none of these symptoms or noises happened during the process. Hard braking does not produce the problem, only on slow, firm, rolling stops.

With the high-temp lube on the ABS, would that be the same stuff used on suspension points and bearings?