Brake shudder after new pads and rotors install
 

So I installed new pads and rotors on all 4 corners of our Sienna SE, as well as changed out the brake fluid with a Mitivac-type device.

I proceeded to bed the brakes using the Powerstop procedure.

Now the minivan has developed a shudder when the brakes are applied at highway speeds.

The weird thing is, I was VERY careful and meticulous in all aspects of the installation procedure: brushing out all the rust on the wheel hub surface prior to rotor installation, torquing down the caliper mounting bolts and slide pins at the correct torque values, etc. I didn't measure rotor runout, only because I didn't have the device and I really didn't think it was necessary. I've done numerous brake jobs in the past, and this is the first time brake shudder has happened to me.

So my questions:

(1) Is it possible they sent me a bum rotor, even though it was brand new ??

(2) Would replacing the brake caliper be my next step ?? There was metal-to-metal contact prior to installation, so I'm wondering if I had damaged the 2-piston front rotor when I pushed the piston back (yes, I had the brake fluid reservoir cap off when I pushed it back using a C-clamp).

Has anything like this ever happened to you guys and what did you do to solve the problem ??

Also, I guess my next step is to measure runout.

How difficult is it and what is the correct procedure on how to do it correctly ??

Welp, I dove into the van's brakes again.

Inspected the caliper slide pins on all 4 corners to make sure they moved freely. Lifted the calipers and made sure the pistons advanced, since I pushed them in all the way to make clearance for the thicker pads. I was thinking the pulsation was caused by a stuck piston, but my inspection and the way the van traveled down the road suggested that the calipers weren't the culprit.

I did, however, replaced both the front rotors. Instead of sticking to Powerstop, I decided to go with Raybestos.

This time, I didn't perform the bedding procedure as suggested by Powerstop. I will conform to the new car manual, which states no hard braking for the first 500 miles. When I went for a test drive, I sped up to 70 mph and gradually applied the brakes.

Smooth as silk. The "old" rotors produced violent shuddering that was very unnerving.

I then continued the 70 mph => 50 mph gradual stopping procedure about 8 more times. Hopefully, the brake material deposited evenly on the rotors' surface.

Anyway, thanks for all your help. I appreciate it.

:lol: :D

I bought Z23 Evolution drilled and slotted brake rotors and pads from Powerstop for my E46, which I will install this weekend.

Hopefully, I won't run into the same problem.

Fingers crossed !!!!

:eeps: :eeps:

(I'll probably start working on it on Saturday instead of Friday. Tomorrow, I'll be attending the last Reno Air Race. Can't believe this will be the last year after 59 years. How sad ....).

Good luck!

Thanks !!