Grinding Ceramic Brake Pads - Loud!

How's the brake fluid level? If overfull thermal expansion can cause the brakes to bind.

Ceramic usually means quieter...

 

how many miles on them?

 

When servicing the brakes, we always recommend changing the pads and cutting or replacing the rotors. Don’t cheap yourself by not servicing your rotors because overtime, the rotors have wear and tear on them and will cause hot spots, grooves and bumps that will come back and cause noise issues or vibration. Also, make sure to lube all brake hardwares as that can cause noise issue. If I were you, have the rotors cut if it’s cheap or replace it, then lube the hardware and see if the noise come back.

As for the hole to remove the rotors, I believe it’s 8.5 bolt or M8, you can find them at Home Depot.

 

I agree, change or grind the rotors or the pads will become the old pads in a few miles, ceramic pads will take longer and be louder.

 

M8x1.25, and they should be fully treaded around 25mm long minimum, or at least 25mm threaded length.

I was NOT confident I had the right size first time; the threaded holes were so rusty. I just kept screwing them in till they started fighting, then backed them out, and blew out the loosened rust, and repeated, till they finally got through.

FWIW, I've regularly cheaped out, just reused the rotors. I do check the runout and thickness against spec occasionally.

Also, with our third gen, first time I did the rears I messed up the caliper piston orientation. The rotors were really rusty on about 50% of the inside face and outer face had a lot of scoring, all due to uneven pad pressure. I removed the rotors (with the help of those bolts) and just steel wooled the rust off best I could, put everything back together, with new pads .

And they sounded like shiiite, at first. A week later I could barely hear it. By a month, you'd never know there was an issue: and the rotor scoring "healed", they looked and performed great.

They're still on there about 4 years later.

 

During the course of a brake pad lifetime, the fluid level goes down. Owner may replenish. Then replacing pads pushes brake fluid back to reservoir and overfull. Still waiting and hoping it is that simple....

“I also think that they might be dragging on the rotor a bit even when I’m not braking”

 

It’s not that simple... overflowing the brake fluids doesn’t cause noise issue. It’ll probably eat the paint if it’s not washed away though.

 

Yes it can if left over full. Brake fluid does expand when heated. Pads are constantly being pressed against rotor. Even ceramic pads always pressed won’t start to scream?

 

Side effect hot driver side front wheel, and front driver side tire pressure goes up compared to right front tire. (Ask me how I know).

 

There was no sound, hence my question about the pads not screaming after a while:

http://www.giuliaforums.com/forum/602-wheel-tires/26322-hot-front-left-driver-side-front-tire-after-driving-while-2-psi-higher-normal.html

 

Not probably, will.

It’s corrosive to paint.

You’d know where it went if the reservoir overflowed.

 

if you don't top up brake fluid you won't have overflow, as simple as that.

If you've got hot wheels something is wrong, causing drag. Just stating the obvious I know.

 

The hot wheel/high tire pressure in the Giulia went away after I found the brake fluid level up to the bottom of the filler neck in the reservoir, and siphoned enough that the level was between the marks. I must confess there was no sound! I felt like the master Giulia driver the car drove so smoothly, meaning from start I wouldn't jerk it nor when stopping would it jerk. (My smooth driver of the year title also went away).

I could be wrong. The Prius has that weird brake fluid accumulator that sucks the level down like a toilet flushing. I was confused how to set the level before reading the service information. (I actually tried keeping both the high level and low levels between the marks, and I left it that way even after reading how to adjust it the Toyota way).

Just my $0.02.

 

If I pop the hood on ours, by sneaking in through the passenger door, the brake fluid level is near the top mark. Open the drivers door, and the pumps start, and level drops, about 3/4". Our brake pads are at about 80% thickness, it's a little complicated: our fronts are somewhat worn (around 7 mm remaining), and the rears are closer to full thickness (10 mm?) since I replaced them prematurely, due to messing up something on the rear brakes.

Again, if you don't have a leak in the system, and your pads are near-new, I would get the level so it's as described above, and then don't mess with it. In a normally functioning system, that's not leaking, there's never a need to top up the brake fluid. It drops as pads wear, and with replacement pads it goes back up.

FWIW, I would recommend tri yearly or 30K fluid replacement, that's the Toyota Canada recommendation. Not sure of the DIY procedure for the v, how similar it would be to regular 3rd gen Prius. I'll attach that, just for reference. Also, you should watch @NutzAboutBolts video on brake fluid change, it's in 3rd gen maintenance section.

So, having basted out brake fluid would you say brakes are back to normal for you?

 

The Giulia was brand spanking new. I was trying to figure out what was making the front driver wheel hot and originally thought it was the huge turbo. After sucking out the excess brake fluid yes, right away the left front tire stayed within 1 PSI from the front right. As the reservoir is compartmentalized to help in preventing total fluid loss in case of leak, there were pockets where fluid seemed still to the top. Finally I decided to press the brake pedal as hard as I could, to possibly even the level out. (I searched up brake fluid overfull and found other instances of issues with brakes locking up if not kept within the range as marked). Perfectly normal after that...

For the Prius v, without techstream, it is just to check that the fluid level is above MIN with power switch (IG) ON. If necessary fill to the "support line" with IG ON. (There is apparently a middle marker, the "support line", on the reservoir).