Glazed Pads

Messages
1,395
Location
Kennett Square, PA
My buddy leases a new Caddy SUV. Very low miles and easy driving short tripping around town. Started hearing intermittent noise from front wheel when driving and not applying brakes. Took it in and dealer said pads are glazed and glazing will go away as the pads wear. I thought glazing came from high temperatures due to hard braking or a sticky caliper. Also, once pads are glazed, braking capacity is diminished causing a safety issue. Does the glazing explanation sound right? Should the pads be replaced or at least deglazed? Thanks.
 
Messages
2,426
Location
Seattle-ish, WA
Not going to change w/o doing something differently. He could try re-bedding; I have had that work with lightly glazed pads. Perhaps he rides his brakes a bit in town so much? That would cause it.

Clear road, do some HARD stops 60 down to 30. Drive back up to 60 and repeat, with about a mile in between to cool down a bit. Do it eight to 10 times.

Also need to check if rotors are glazed, too. But nothing is going to fix itself.
 
Messages
8,923
Location
North Carolina
The pads probably have rust from the rotors embedded in them - or the chamfer is worn and they're noisy when flat.

Try giving them a blast with brake cleaner between the pads/rotor and then re-bedding them.
 
Messages
24,401
Location
CA
The pads probably have rust from the rotors embedded in them - or the chamfer is worn and they're noisy when flat.

Try giving them a blast with brake cleaner between the pads/rotor and then re-bedding them.
I've had the best success with removing the pads and dragging them across 80 grit sandpaper, then reassembling. Of course, the contact points and slide pins should be cleaned and greased, if applicable.
 
Messages
8,923
Location
North Carolina
I've had the best success with removing the pads and dragging them across 80 grit sandpaper, then reassembling. Of course, the contact points and slide pins should be cleaned and greased, if applicable.
From my time at VW that was an approved procedure for people complaining about a low speed squeal.

Never believed in losing pad material for a squeal though.
 

artbuc

Thread starter
Messages
1,395
Location
Kennett Square, PA
Thx for responses. My friend was given a Service Bulletin which perfectly described his symptoms. Cadillac says intermittent noise when vehicle is first driven is due to problem with pad material and that engineers are working on a fix. Caddy issued a similar bulletin a couple years ago for rear brakes. The service writer who told him pads were glazed didn’t know what he talking about...a real shock, right? Hard to believe Caddy can’t get brake pad material right...go figure.
 
Messages
8,923
Location
North Carolina
I feel like this is as good a time as any to relate a statement from an unnamed Porsche engineer:

"Europeans don't care if their brakes make noise, as long as they stop. Americans don't care if their brakes stop, as long as they are quiet."
 
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