Brake pad failure.

[MGregoir]

I somehow had the inside pad on my right front wheel have a massive chunk of the friction material break off and catch in the caliper, and the pad backing gouged the rotor heavily. I checked the pads 6,000 miles ago and they had about 40% life left. That one kind of bends my mind as it's a failure I haven't seen or heard of before.

So I have to replace at least one rotor and I am doing front pads.

1. Besides the obvious pad set and rotor, I will take the other rotor in to get turned on the brake lathe. After this, do I need a shim plate to put behind the rotor to put it back in position? It's an OEM rotor with 90,000 miles that has been machined once before about 50,000 miles ago. Or should I just do both front rotors and sets of pads? Brake force is good, low noise is better.

2. Raybestos Advanced Technology, Professional Grade, Wagner ThermoQuiet or something NAPA reboxes? It's going to come down to whatever is in stock. As well, is there a major difference between the grey iron rotors if they aren't slotted and match the OEM "noise dampening iron." I can get a deal on the Raybestos.

3. What am I going to need for shims, lube, fasteners, cleaners, etc. to do this? I have the instructions for doing it somewhere but I am just wondering what other materials do I need?

Have at it guys...

 

[ChiTDI]

Anti seize for the hub/rotor match up, good lube for the caliper pins and the ways, (I like Sil/Glyde from NAPA) spray Brakleen for the pad/rotor removal and to clean the new/machined rotors, Disc /Brake quiet (spray) for the back of the pads. You can even put some on the shims,,etc. for extra quiet. NOT on the braking surface. Your choice of pad and rotors, torque wrench, good lighting and a dry work area.

 

[ChiTDI]

Your question on the rotor shims leads me to think no. There may be shims for the pads, used as sound deadening, and would come with the hardware for the pads, if needed or desired. I just usually reuse what's on there, depending on condition.
NAPA has a new pad that is worth looking at. I just put Wagner "Edge" on an Avalon, uneventfully. Saw the new Napa ones after that, I've used Hawk and Akebono with good results and Raybestos has always had good reputation.
Let us know what worked and what didn't.

 

[Donald]

I would not machine a rotor a second time. Most places do not do it at all now. Decent rotors are not that expensive and are a better way to go.

With respect to a chunk of break pad coming off and damaging the rotor, unless a defect in the brake pad, I suspect one or both tabs of the brake pad got hung up, and instead of the piston moving the pad as a whole it bent the middle and broke a piece off. I had this happen once when I changed pads too quickly, it was Feb, my hands were very cold and I just wanted it done.

 

[MGregoir]

I have Wagner on there, but I can get a deal on Raybestos. NAPA is most expensive and I believe re-branded Raybestos, so it will be the choice if it's what I can find in stock.

NAPA doesn't have the awesome warranty deal in Canada.

The rotor shim is based on three different thickness shims Raybestos makes to back machined rotors, I think.

Looks like Raybestos Professional Grade Ceramic pads and PG rotor, can't find the PG Plus in town. Two different parts stores and then go to NAPA and pick up the lube and anti-seize there because I get discount on it. The other places the parts are cheaper than they are at NAPA with the discount, oddly enough.

 

[ChiTDI]

Forgot to add: some steel wool for removing the rust from the hub where it butts the rotor, and for "sanding" the ways where the pads sit.
Enjoy the work, let us know how you did.
Good advice on buying new rotors IMHO.

 

[MGregoir]

I ended up with Raybestos PG rotors reboxed as NAPA, as far as I can tell, and Raybestos PG Ceramic pads.

The rotors were about $6 more than RockAuto price, basically, and the pads were about 40% more but it's Canada and I bought at retail. That was after discount from regular price.

Rotors were less expensive than I thought they would be so the difference between pulling the other rotor off, taking it in, getting it turned (if it would meet runout limit) and bringing it home to put back on would not save the money to justify not buying a new rotor.

I also picked up anti-seize, silicone lube, brake fluid (they say to suction out half when changing pads in the instructions, and I'll put fresh back in), and I have saBesto in the shop to clean everything up.

The book makes it look pretty straightforward, and I know how to properly bed brakes in now so I'll make the changes, bed them in and should be good to go for another 40,000 miles. Oddly enough, the brake bias on this car must be hugely forward as the rear shoes still have quite a bit of meat left on them and I don't think they have ever been changed.

 

[mechtech2]

Anti seize is good for the rotor/hub contact, but it is NOT a lubricant, and is sub standard for lubing brake parts.
Use dedicated brake grease or high temp wheel bearing grease.

 

[MGregoir]

So I replaced the pads and rotors, it was pretty uneventful. The pads practically fell out of the shims so they were not bound up, and everything was greased nicely so nothing was locking up.

The pad that failed had an obvious split in it and the rotor had I would say about 3/16" of the rotor surface wore off compared to the other rotor by the damaged pad, it was ugly.

The inboard pad on the other side was cracked in the center but also moving freely. I measured at least 30% wear left on all the intact pads.

I put everything back together, bedded the new pads/rotors in and all is well again.

 

[wantin150]

Always replace rotors in pairs. I sounds like you bought two so that's good. Only doing one is begging for disaster.

I had a cracked rotor on a patrol car. State maint only authorized one to be replaced so they turned the "good" one and replaced the bad. I got a few miles down the road and had to hit the brakes hard to turn on a car. The difference in materials put me in the median. Luckily, it was paved and wide enough not to send my into oncoming traffic. State maint then authorized the second one.

 

[Smoky14]

I ended up with Raybestos PG rotors reboxed as

I also picked up anti-seize, silicone lube, brake fluid (they say to suction out half when changing pads in the instructions, and I'll put fresh back in), and I have saBesto in the shop to clean everything up.

I hope you didn't just push the pistons back and force the old fluid back to the master, you can get dirt etc in the master and anti- skid. Just open the bleeder and let it escape there.
Smoky

 

[mechtech2]

wantin - That is expected until the cut rotor and pads seat in. This takes a hundred miles or more.
Don't get me wrong, I believe in replacing brakes in pairs.