Just replaced the 911 SC rotors, front and rear with Zimmers and new pads all the way around. Now when I turn right I get this sound ...almost like a harmonic tone when I turn right. Never did this with the old rotors and pads. Brakes work fine and it's not the tire rubbing as I checked it out.
Weird stuff........ if I was a betting man I would say its the pads on the rotor singing but why?
Dave
Full Version: Weird sound from Passenger rear when I turn right
you need to bed the pads.
You may also need to rebuild one of the calipers.
Drive around a bit in normal traffic.
Get out and feel the wheel at each corner.
If one of them is super hot, the caliper is dragging.
I had that same sound, it was a caliper that was needing a rebuild.
Rich
You may also need to rebuild one of the calipers.
Drive around a bit in normal traffic.
Get out and feel the wheel at each corner.
If one of them is super hot, the caliper is dragging.
I had that same sound, it was a caliper that was needing a rebuild.
Rich
QUOTE(r_towle @ Mar 16 2015, 11:08 AM) 
you need to bed the pads.
You may also need to rebuild one of the calipers.
Drive around a bit in normal traffic.
Get out and feel the wheel at each corner.
If one of them is super hot, the caliper is dragging.
I had that same sound, it was a caliper that was needing a rebuild.
Rich
Great info.... yeah it has to be something like that although the calipers were not even messed with and pad wear on the rears was nice an uniformed from both sides. Will try and get the wife to help me later tomorrow and will inspect the pads as the peddle is depressed.
Dave
When I start hearing weird sounds from the passenger's rear I throw 'em out. 
Just sayin'...
Just sayin'...
Pads are installed within the caliper and the caliper rotates with the steering knuckle. Nothing should abnormally rub. Hate to ask, but are you sure you installed the rotors and pads correctly?
Want to pinpoint the source? Reinstall the old pads in one of the suspected corners and road test. Repeat until the noise disappears, then inspect that corner a little closer.
Sherwood
Want to pinpoint the source? Reinstall the old pads in one of the suspected corners and road test. Repeat until the noise disappears, then inspect that corner a little closer.
Sherwood
QUOTE(screenguy914 @ Mar 16 2015, 02:41 PM)
Pads are installed within the caliper and the caliper rotates with the steering knuckle. Nothing should abnormally rub. Hate to ask, but are you sure you installed the rotors and pads correctly?
Want to pinpoint the source? Reinstall the old pads in one of the suspected corners and road test. Repeat until the noise disappears, then inspect that corner a little closer.
Sherwood
Well I have done some dumb things as I'm sure most of have over the years but pulling a REAR rotor is nothing more than two bolts to remove the caliper and two small screws to remove the rotor. I mean it's about as basic as it gets. The pads are even simpler and I have done about a dozen or so of these jobs over the years. I don't have time to do anything today but will inspect more tomorrow. I do have the old pads.
Dave
QUOTE(screenguy914 @ Mar 16 2015, 02:41 PM)
Pads are installed within the caliper and the caliper rotates with the steering knuckle. Nothing should abnormally rub. Hate to ask, but are you sure you installed the rotors and pads correctly?
Want to pinpoint the source? Reinstall the old pads in one of the suspected corners and road test. Repeat until the noise disappears, then inspect that corner a little closer.
Sherwood
Well I have done some dumb things as I'm sure most of have over the years but pulling a REAR rotor is nothing more than two bolts to remove the caliper and two small screws to remove the rotor. I mean it's about as basic as it gets. The pads are even simpler and I have done about a dozen or so of these jobs over the years. I don't have time to do anything today but will inspect more tomorrow. I do have the old pads.
Dave
So, you are not using the stock calipers? So no venting clearance adjustment required?
I would jack the rear up and take the wheel off and spin it by hand then you can see/hear where the noise is coming from.
On my 5 lug converted hub the outside rim of the hub is slightly pushed out where the studs are mounted. This increase in diameter wouldn't let the rotor install flush against the hub resulting in a slight angle on the rotor. Everytime the rotor went around it would brush the brake pad.
I would jack the rear up and take the wheel off and spin it by hand then you can see/hear where the noise is coming from.
On my 5 lug converted hub the outside rim of the hub is slightly pushed out where the studs are mounted. This increase in diameter wouldn't let the rotor install flush against the hub resulting in a slight angle on the rotor. Everytime the rotor went around it would brush the brake pad.
QUOTE(r_towle @ Mar 16 2015, 11:08 AM)
I had that same sound, it was a caliper that was needing a rebuild.
Rich
Same here. Caliper piston was sticking.
The piston sticks due to rust inside.
Calipers do not retract, ever.
They are pressed by the power of the hydraulic system, but they retract by simple variations in the rotor tapping them, just a hair.
Also, the pressure needs to be relieved.
There are two causes, but first see if the rear caliper in question is hotter than the other on an average trip.
If it's hot, could be two things.
The rubber brake line gets clogged from the inside, similar to clogged arteries.
Just old brake fluid does this, and 40 years.
So this can prevent a caliper from retracting.
Then there is a harder one which is the piston is not retracting into the caliper.
For that, buy a rebuild kit from Eric at PMB, pull it apart, clean the inside of the cylinder, put it back together....done.
With custom calipers also check you are not rubbing the wheel inside, and you are not rubbing the dust cover.
Rich
Calipers do not retract, ever.
They are pressed by the power of the hydraulic system, but they retract by simple variations in the rotor tapping them, just a hair.
Also, the pressure needs to be relieved.
There are two causes, but first see if the rear caliper in question is hotter than the other on an average trip.
If it's hot, could be two things.
The rubber brake line gets clogged from the inside, similar to clogged arteries.
Just old brake fluid does this, and 40 years.
So this can prevent a caliper from retracting.
Then there is a harder one which is the piston is not retracting into the caliper.
For that, buy a rebuild kit from Eric at PMB, pull it apart, clean the inside of the cylinder, put it back together....done.
With custom calipers also check you are not rubbing the wheel inside, and you are not rubbing the dust cover.
Rich
QUOTE(r_towle @ Mar 16 2015, 04:42 PM)
The piston sticks due to rust inside.
Calipers do not retract, ever.
They are pressed by the power of the hydraulic system, but they retract by simple variations in the rotor tapping them, just a hair.
Also, the pressure needs to be relieved.
There are two causes, but first see if the rear caliper in question is hotter than the other on an average trip.
If it's hot, could be two things.
The rubber brake line gets clogged from the inside, similar to clogged arteries.
Just old brake fluid does this, and 40 years.
So this can prevent a caliper from retracting.
Then there is a harder one which is the piston is not retracting into the caliper.
For that, buy a rebuild kit from Eric at PMB, pull it apart, clean the inside of the cylinder, put it back together....done.
With custom calipers also check you are not rubbing the wheel inside, and you are not rubbing the dust cover.
Rich
Well I may have found the issue but I'm not going to take it for a spin until tomorrow. Both front wheel bearings were loose. Funny this was the first time I actually went to the archive and found that they want that slotted washer to move but still be tight. I have always just felt the right spot. Both were loose to the point of movement when I tugged at the wheel when jacked up. Used my feel as I have always done and it spins with no wiggle. We shall see........ thought the sound was coming from the rear but hell who knows.
Dave
QUOTE(Downerman @ Mar 16 2015, 05:29 PM)
QUOTE(r_towle @ Mar 16 2015, 04:42 PM)
The piston sticks due to rust inside.
Calipers do not retract, ever.
They are pressed by the power of the hydraulic system, but they retract by simple variations in the rotor tapping them, just a hair.
Also, the pressure needs to be relieved.
There are two causes, but first see if the rear caliper in question is hotter than the other on an average trip.
If it's hot, could be two things.
The rubber brake line gets clogged from the inside, similar to clogged arteries.
Just old brake fluid does this, and 40 years.
So this can prevent a caliper from retracting.
Then there is a harder one which is the piston is not retracting into the caliper.
For that, buy a rebuild kit from Eric at PMB, pull it apart, clean the inside of the cylinder, put it back together....done.
With custom calipers also check you are not rubbing the wheel inside, and you are not rubbing the dust cover.
Rich
Well I may have found the issue but I'm not going to take it for a spin until tomorrow. Both front wheel bearings were loose. Funny this was the first time I actually went to the archive and found that they want that slotted washer to move but still be tight. I have always just felt the right spot. Both were loose to the point of movement when I tugged at the wheel when jacked up. Used my feel as I have always done and it spins with no wiggle. We shall see........ thought the sound was coming from the rear but hell who knows.
Dave
Well guys.... I checked each and every pad as my daughter depressed the brakes. They were all moving. Apparently the adjustment of the front wheel bearings did the trick but the jury is still out because I have not yet taken the car out on a nice long twistie road. That's when I will be totally comfortable with it. thank you all for your comments and suggestions.
Dave
QUOTE(Downerman @ Mar 25 2015, 10:57 AM)
QUOTE(Downerman @ Mar 16 2015, 05:29 PM)
QUOTE(r_towle @ Mar 16 2015, 04:42 PM)
The piston sticks due to rust inside.
Calipers do not retract, ever.
They are pressed by the power of the hydraulic system, but they retract by simple variations in the rotor tapping them, just a hair.
Also, the pressure needs to be relieved.
There are two causes, but first see if the rear caliper in question is hotter than the other on an average trip.
If it's hot, could be two things.
The rubber brake line gets clogged from the inside, similar to clogged arteries.
Just old brake fluid does this, and 40 years.
So this can prevent a caliper from retracting.
Then there is a harder one which is the piston is not retracting into the caliper.
For that, buy a rebuild kit from Eric at PMB, pull it apart, clean the inside of the cylinder, put it back together....done.
With custom calipers also check you are not rubbing the wheel inside, and you are not rubbing the dust cover.
Rich
Well I may have found the issue but I'm not going to take it for a spin until tomorrow. Both front wheel bearings were loose. Funny this was the first time I actually went to the archive and found that they want that slotted washer to move but still be tight. I have always just felt the right spot. Both were loose to the point of movement when I tugged at the wheel when jacked up. Used my feel as I have always done and it spins with no wiggle. We shall see........ thought the sound was coming from the rear but hell who knows.
Dave
Well guys.... I checked each and every pad as my daughter depressed the brakes. They were all moving. Apparently the adjustment of the front wheel bearings did the trick but the jury is still out because I have not yet taken the car out on a nice long twistie road. That's when I will be totally comfortable with it. thank you all for your comments and suggestions.
Dave
Old post but I thought I would share. Turns out I purchased the rebuilds for the 911SC calipers and went through them all. Apparently I need glasses because 3 out of the 4 calipers had one stuck piston. Always had to really stand on the breaks to get any hard breaking out of them. What an idiot. Well there fixed and with the fairly new rotors and pads its much more effective. Imagine that. Thanks for those suggestions...it just took me awhile.
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