'96 C36 - new front brakes squeal badly
Thread Starter
Member
Joined: Jun 2005
Posts: 236
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From: SE Massachusetts
2008 911 C2S, 2009 SL63
'96 C36 - new front brakes squeal badly
History:
Took our 1996 C36 in to the dealer in the middle of September because the brakes were "grabbing". They found warped rotors and worn pads all the way around, so they replaced the pads and rotors on all four wheels.
Three weeks later, the front brakes start squealing badly when braking from 5MPH to a full stop. By "badly", I mean loud enough to hear blocks away. This is not a small minor squeak that we hear sometimes on our CLK, this is a full loud sustained squeal. Made another service appt. at the dealer, and they replaced the front pads and rotors again on both sides.
Two weeks after that, the squeal is back...again. And again, from 5MPH to a full stop. Made another appt., again they replaced just front pads and rotors.
Picked it up on the Tues. night before Thanksgiving.
The NEXT DAY (Wed before Thanksgiving), took it out and after driving for 2 miles, at the first full stop, the squeal is back. This time, however, it has just gotten louder and louder, and it now squeals from 20MPH all the way to a full stop, or even just slowing down.
If the brakes are wet (driving during rain), they are pretty much quiet - the squeal is there, but hardly noticeable. If I come to a quick, short, jarring stop, you don't hear it. But a smooth rolling stop causes people for blocks to turn and stare - the brakes squeal louder than a garbage truck or city bus.
I've got another service appt. back at the same dealer for this Thurs. What can I tell them to make SURE they fix it right this time? I'd already be taking the car someplace else, but then we'd have to pay again, maybe not for parts, but for labor. Once they fix this, this is the last time they'll see that car.
Any advice is appreciated. Thanks!
Took our 1996 C36 in to the dealer in the middle of September because the brakes were "grabbing". They found warped rotors and worn pads all the way around, so they replaced the pads and rotors on all four wheels.
Three weeks later, the front brakes start squealing badly when braking from 5MPH to a full stop. By "badly", I mean loud enough to hear blocks away. This is not a small minor squeak that we hear sometimes on our CLK, this is a full loud sustained squeal. Made another service appt. at the dealer, and they replaced the front pads and rotors again on both sides.
Two weeks after that, the squeal is back...again. And again, from 5MPH to a full stop. Made another appt., again they replaced just front pads and rotors.
Picked it up on the Tues. night before Thanksgiving.
The NEXT DAY (Wed before Thanksgiving), took it out and after driving for 2 miles, at the first full stop, the squeal is back. This time, however, it has just gotten louder and louder, and it now squeals from 20MPH all the way to a full stop, or even just slowing down.
If the brakes are wet (driving during rain), they are pretty much quiet - the squeal is there, but hardly noticeable. If I come to a quick, short, jarring stop, you don't hear it. But a smooth rolling stop causes people for blocks to turn and stare - the brakes squeal louder than a garbage truck or city bus.
I've got another service appt. back at the same dealer for this Thurs. What can I tell them to make SURE they fix it right this time? I'd already be taking the car someplace else, but then we'd have to pay again, maybe not for parts, but for labor. Once they fix this, this is the last time they'll see that car.
Any advice is appreciated. Thanks!
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Joined: Nov 2001
Posts: 5,851
Likes: 196
From: Huntington Beach, Ca.
'17 Jaguar XF
My guess....
They didn't really change the pads and rotors again like they said. Maybe they did something like sand them (break the 'glaze') and they are just hoping it will go away on it's own. Which it could, or could not. I would discretely mark them this time. I know this sounds cynical but I find it hard to believe three sets of pads/rotors are bad unless...unless...they were not broken in properly.
Thread Starter
Member
Joined: Jun 2005
Posts: 236
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From: SE Massachusetts
2008 911 C2S, 2009 SL63
So what is the proper way to break in new brakes? Should the dealer do it, or us? Everytime we get the car back, it's got 10 more miles on it than when we took it in, so they are driving it.
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Joined: Nov 2001
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From: Philadelphia area
2010 ML550, 2010 E350 4M, 1966 Corvette Convt C2
Perhaps they did not use the anti squeal paste, maybe they should surface the new rotors also. As so far as break in, 10 miles will not do it. Takes way longer than that. The test drive was most likely to see if they squealed and I bet they did not when you picked it up.
Thread Starter
Member
Joined: Jun 2005
Posts: 236
Likes: 0
From: SE Massachusetts
2008 911 C2S, 2009 SL63
Originally Posted by sosh
Perhaps they did not use the anti squeal paste, maybe they should surface the new rotors also. As so far as break in, 10 miles will not do it. Takes way longer than that. The test drive was most likely to see if they squealed and I bet they did not when you picked it up.
And correct, it did not squeal on the drive home this last time, but did the next day.
MBWorld Fanatic!
Joined: Nov 2001
Posts: 4,260
Likes: 6
From: Philadelphia area
2010 ML550, 2010 E350 4M, 1966 Corvette Convt C2
If it in fact did not squeal when you picked it up the tech certainly felt that the problem was resolved. I had a squeal problem on the 02 ML500 I recently traded for my 06 ML500. Replacing the rotors and pads did nothing, when the pad was changed to a new type, that helped and then they resurfaced (not cut down) the rotors that cured it except in cold weather or when there was salt residue on the roads. Try finding a quiet road and making some hard, panic type stops from about 35 MPH. May help.
MBWorld Fanatic!
Joined: Nov 2001
Posts: 5,851
Likes: 196
From: Huntington Beach, Ca.
'17 Jaguar XF
Pad break in....
There are several different methods posted in the forum and they all basically do the same thing.....heat the pads with a series (3 - 5 times?) of bringing the car up to speed (?40 mph) then slowing down but not to a stop, never let the pads stay under pressure to the rotor at a stop (use park brake), then stop and let it cool off (1/2 hour). If you read up on it you'll find 1. rotors do not 'warp'. 2. improper break in ruins the pads and rotors 3. letting new pads get hot and rest against the rotors under pressure (foot on brake) causes a reaction between the pad and rotor that gives it a spot that grabs during braking causing the vibration/oscilation usually associated with 'warping' and squeeling. Tell the dealer your frustration (like they aren't frustrated too!) and maybe they should either do it or you should do it when you pick up the car. Hard/panic applications of new pads and rotors is not a good idea. Resurfacing then proper break in can work if the problem happens. I am not a mechanic but my brakes don't squeel (usually 
)
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