Rattle coming from the front--is it from the brakes/backing plate

due to regen braking your brake pads and shoes last an obscenely long time, however, every 50K miles you need to lube your caliper slides, anti-seize your caliper bolts, and clean & adjust your rear brake drums. You also need to put some fine sandpaper to the inside of your rear brake drums as well as the shoes where they make contact with each other (aka deglazing).

You or any mechanic can do this and will most likely get rid of any noises caused by trapped brake dust in your rear drums. You need to go to a Toyota stealership every 100K miles (or 5 years if you drive less than 20K miles a year as most americans do) for a brake bleed and fresh brake fluid. Brake fluid is a hydraulic fluid and over time it absorbs water and its effectivity as a hydraulic fluid diminishes over time.

I explained how to deglaze the rear shoes, the front pads can be done while driving, while driving under 50 mph (I use 47mph to be safe) put the car in neutral and stop the car in a normal fashion, such as coming to a red light. If it is wet and/or humid do this once a week. If it is a dry arid season you can do it once a month.

Most brake shops give you a free inspection, if doing the above general maintenance doesn't solve it and a brake shop says your braking system is functioning properly, I would guess it to be a wheel bearing as many Prius owners are forced to replace those.

 

I would have it fixed before I take a long trip. If its rattling, it is loose and may (possibly) cause other problems if let go. It should be easy enough to fix (if it is indeed the brake backing plate/dust cover).

 

Let me guess, it only makes the noise when you hit a small bump while the brakes ARE NOT applied? When the brake are on when you hit a bump it doesn't happen, correct?
If so I do know how to repair this, if the above doesn't apply to your situation then disregard.

 

Hello Cory, this is exactly what it happening with my car. I just recently purchased it and I added air in the tires 42 in front 40 in the rear and it started making a rattling noise but only when I hit a bump and not when I am breaking

 

Hello Cory, this is exactly what it happening with my car. I just recently purchased 2007 prius with 120000 miles on it and I added air in the tires 42 in front 40 in the rear and it started making a rattling noise but only when I hit a bump and not when I am braking. I stopped in at a brake repair shop to have them take a look at it and they couldn't find anything so they said they'd bent the brake backing plate a little thinking that it might just be rattling but it didn't change anything. not sure if they did any damage by bending that plate or if it makes a difference. But would also like to find out from you or someone else what the problem is with the rattling. Thanks

 

Hey, PLEASE let me know what you do. This is exactly my issue as well. Thanks!!!

 

My 2007 does this too. One of the guys at work had the same problem on his 2008. He took the brake pads out and applied high temp brake grease to the pad edges and fixed the noise.
Hope this helps. I'll be doing this next week.

 

I just fixed mine ! I had a metallic rattle in the left front over sharp bumps - particularly noticeable with the windows down. I lubed the caliper pins with clear brake lube, and applied high-temp brake grease to the upper and lower edges of the pads. I also applied a small amount of brake grease to the fingers of the caliper that contact the back of the outer pads. It is quiet now !!

 

I know this is an old thread, but just wanted to chip in a few thoughts on the disc pad's rattling. In my '07 the issue was the abutment shims, which prevent the pads from moving up and down, were worn out. These are typically included in the "disc brake hardware kit" sold by the major auto-parts sites.

The symptoms i had were that the front brakes emitted a loud "chatter" or "rattle" kind of noise when driving over bumps. The noise would go away when pushing the brake pedal enough to engage the disc brakes, even when riding over bumps.

These hardware kits contain the abutment shims, as well as sometimes the slider pin boots. These shims are sometimes called slider shims, or anti-rattle shims. they are NOT the same as the clips that go on the back of the pads.

One word of caution for these hardware kits: i bought a kit from Dorman, and it included 4x identical shims. This is NOT right. These kits should have 2x of two different types of abutment shim. one shim has a "P" shaped edge, which contacts the pads, and prevents rattling. The other 2x shims don't have this "P" edge. These should be paired together with 1x P shim on each side. i've included pictures of these shims below.

I advise putting the "P" shaped shim on the top. This should prevent it from wearing out prematurely, as it won't be constantly compressed when you actuate the brakes.

 

I'm having the exact same problem on my 2008 prius. Can you post what fixed it?

 

Thank you for this info, what parts did you get to correct the issue that were the correct ones, better put, where did you finally get the correct parts from ?

 

Depending on your year and other things, one of these should work:
2007 TOYOTA PRIUS 1.5L L4 ELECTRIC/GAS Disc Brake Hardware Kit | RockAuto

Or else browse to your year/model/etc at rockauto or similar, and you're looking for "disc brake hardware kit", or similarly named. good luck!

 

If the abutment clips are the problem, from a Toyota dealer nearby or online, you can buy these:

Disc Brake Fitting Kit Front #04947-47010 | Autoparts.toyota.com

 

Thank you guys