Swapped to disc and now horrible scraping Help

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gdizzle

gdizzle

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66 dart, swapped out old drums (front) to new disc conversion ala Scarebird. 9 inch, SBP etc...
Anyhow got everything buttoned up, and now front driver side pad is grinding on the side of the Hat of the new rotor. see picture. It appears the pad plate is pushing inward scratching a real nice groove into the rotor. And once it gets in the groove, it dont come out unless I stop the car and let it settle. Any ideas on how to fix, correct, redo this thing? Pass side is fine BTW. Also the pad itself is also grinding you can see in the photo.
So if I start driving around , doing some light braking, no prob.. But if I do a heavy brake, then that pad moves into the groove and grinds away for the rest of the time.
Please help . I assume the rotor is now ruined, and so it the pad.
pad1 - 1.jpg
pad13 - 1.jpg

pad12 - 1.jpg
 
Based on what you’ve shown so far I wouldn’t assume the rotor is ruined. The pad seems serviceable as well but obviously you’ll have to figure out why it’s moving around.

Since the passenger side isn’t having this issue, have you compared the calipers and pads from the passenger side to the drivers side to see if there’s any differences?

Is there any play in the rotor or wheel bearings?
 
It looks like your pads are different lengths on the inside and the outside. I have never seen this before. Why are they not the same on both sides of the rotor? If they are supposed to be this way, are you sure you have the right one on the inside?
 
mvh said:
It looks like your pads are different lengths on the inside and the outside. I have never seen this before. Why are they not the same on both sides of the rotor? If they are supposed to be this way, are you sure you have the right one on the inside?
Click to expand...

It’s pretty common. Even a lot of the pads for the 73+ disks aren’t the same on the inside vs the outside. Some of that varies by manufacturer even for the same application.

In this case it’s obvious he has the pads in the right place, the one on the outside won’t fit into the piston side.
 
These calipers came loaded with pads. Rotirs came pre drilled.All of it came from Scarebird. Though the calipers are different from
Eachh other but pads are the same on each side. I do not understand why this pad is hitting the rotor. And when that pads goes into that groove it stays. I even tried greasing the back of pad where it rubs on the caliper but no change.
 
OK. It just seems weird to me -- the pressure would be different on either side of the rotor -- you would think that would lead to a warped rotor, and cause problems with runout. But then, every car I have ever worked on had multi-piston calipers.
 
mvh said:
OK. It just seems weird to me -- the pressure would be different on either side of the rotor -- you would think that would lead to a warped rotor, and cause problems with runout. But then, every car I have ever worked on had multi-piston calipers.
Click to expand...

The same force is exerted on both sides. Equal and opposite, there’s only one piston.

And you’re assuming the pad area is different. It might not be, the longer pad might not be as tall. See that a lot. Different shape with the same area.
 
Have you looked to see if you can loosen the caliper mounting bracket? Maybe there is a little bit of clearance in the holes that will get the room you need. Re tighten mount BEFORE you drive!:steering:
 
mvh said:
OK. It just seems weird to me -- the pressure would be different on either side of the rotor -- you would think that would lead to a warped rotor, and cause problems with runout. But then, every car I have ever worked on had multi-piston calipers.
Click to expand...

Different length pads help eliminate brake chatter.
 
take a flap wheel and take down the metal lip on the pad. Different pad sizes is new to me too but its right there in the pic

DRT%20wheel%20kit-500x500.jpg
 
Yes, that is what Scarebird now says to do. Use a belt sander to remove the metal plate on the pad where it is rubbing. we will see how it goes. Still concerned about the groove in the Rotor hat, but I guess no big deal.
 
If the rotor bothers you that much, swap it out. $140 a pair isn't bad in the grand scheme of things. Rotors for my brother's F150 are that much each.
 
gdizzle said:
Yes, that is what Scarebird now says to do. Use a belt sander to remove the metal plate on the pad where it is rubbing. we will see how it goes. Still concerned about the groove in the Rotor hat, but I guess no big deal.
Click to expand...

The groove in the rotor hat doesn’t look that deep in the pictures compared to the thickness of the rotor hat. But you’re the one looking at it in person, and you’re the one that has to drive on it. If you’re worried about it swap it out.
 
gdizzle said:
Yes, that is what Scarebird now says to do. Use a belt sander to remove the metal plate on the pad where it is rubbing. we will see how it goes. Still concerned about the groove in the Rotor hat, but I guess no big deal.
Click to expand...
A hunch tells me the Caliper or engagement of pads isn't running perpendicular to the Rotor/Axle...
Just a thought (check the Mating surfaces of the Adaptor/Carrier plate to the axle upright for a burr, dirt etc)
Cheers Trev.
(Been involved with brake shop specialist & you'd be surprised what little thing out somewhere else has an effect down the chain of actuation etc)
 
Let me update : I ordered a new set of pads, Wagner MX215. The ones that came with the calipers were Hawk. Well the Hawk pad has a small round nub that is supposed to center the pad in the caliper. The caliper has a large round hole for that nub, way too much play. The Wagner pads have a different elongated nub that actually centers and fits properly into the caliper.
When I installed the Wagner pad, everything works great, no scraping. See my pics:
caliper centering holes - 1.jpg
caliper centering holes2 - 1.jpg
pad nub - 1.jpg
 
Good observation. Scarebird should be notified that their included Hawk pads blow.
 
yep, already sent Scarebird a note. Not sure how I am the only one who had this issue. But then again, I seem to be one of the few people who has a 66 dart sedan, with a slant, with 9 in brakes, and SBP wheels that are 14in.
yay mee. I am still not getting good pedal feel but hopefully I can dial that in as well.
 
gdizzle said:
Yes, that is what Scarebird now says to do. Use a belt sander to remove the metal plate on the pad where it is rubbing. we will see how it goes. Still concerned about the groove in the Rotor hat, but I guess no big deal.
Click to expand...

That rotor will never know that groove is there. Ride on brother. Keep this in mind, too. Not all brake pads are made the same. They can be the same part number for the same application and be made differently. I can almost guarantee you that you can find some pads that will not require modification. Might take a little leg work to the local parts stores, but it's worth a try.

That said, there's not a thing wrong with removing some material from the pad base. This is hot rodding, after all.
 
Yea I intend on using the rotor as is. I also wanted to add in another odd bit. So I bought the set of Wagner MX215 pads on Amazon, got them and look at the defect? How in the heck does this get put into the box. I will also add, the box was sealed, and the 4 pads were shrinkwrapped as a unit. Some one had to handle this unit and stick it in the box right? Or is it all just computer people now? I ordered a replacement from Amazon, and those pads, came in the same box, and same shrinkwrap and were fine. In fact as I look at all the pads, they are all date stamped with the exact same date. Special note, the guy who put the wear indicator did his job, but then the person who's job is to put the clip on it, was stoned.
wagner pads - 1.jpg
 
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