New Pads, New Discs, NEW VIBRATION!!

[dude8383]

This makes no sense...

I installed brand new rotors and pads today.

Brembo Blanks, and Axxis Ultimates.

So after breaking in the pads (3 hard stops from 80-5mph) the car developed a vibration. Its possible the vibration was there before the breaking in period.

My friend broke em in for me.

Anyways, This vibration comes from the front left wheel, whenever I brake, it feels like something is wobbling loose.

Oh to add, when I brake the car doesn't brake smoothly...kinda like the caliper squeezing and letting go of the disc every 2 seconds...a pulsating feel.

It is possible to warp rotors during the break in period? Is it possible that there might be some air in the system after pushing the caliper pistons back in to their housings?

I've torqued down everything on the left...

What do you guys think?

Hope that wasn't too confusing!

[Jand3rson]

Did you bleed your brakes and/or replace your brake fluid? You really should bleed your brakes whenever you replace the pads and rotors. It's possible you've got air in your lines, or uneven pressue, which could cause the pulsating you're getting.

[dude8383]

Did you bleed your brakes and/or replace your brake fluid? You really should bleed your brakes whenever you replace the pads and rotors. It's possible you've got air in your lines, or uneven pressue, which could cause the pulsating you're getting.

I had no idea that was necessary. I don't remember seeing anything about it in the manual!

However, I will bleed em just to be on the safe side.

I'll keep you posted.

Thanks

[T.Dot_E30]

most likely a defective rotor.

Bleeding is not necessary, but it is a good practise.

[PeaveyBassist]

You dont have to bleed them every time you change pads/rotors but it is sometimes necessary otherwise the pedal is soft. Jack the car up and shake the front left wheel side to side like youre turning. Hold the front side of the wheel and back side and shake. Their shouldnt be any play there. If there is, look on the opposite side and all the balljoints and control arm bushing. Shudder when braking could be badly warped rotors, loose ball joints (probably control arm ones), worn control arm bushing, or a caliper starting to lock up.

Will

[StereoInstaller1]

Do you know how to inspect control arm bushings? Mine were shot...the car shuddered like a dog shitting a peach pit while braking...A set of AKG urethane CABs fixed it completely.

GL!
Luke

[e30polak]

check rotors first, if u feel steering wheel vibration they r a very likely candidate, since u just changed them. if it isn't a defective rotor, then check for play in the bushings.

[dude8383]

You dont have to bleed them every time you change pads/rotors but it is sometimes necessary otherwise the pedal is soft. Jack the car up and shake the front left wheel side to side like youre turning. Hold the front side of the wheel and back side and shake. Their shouldnt be any play there. If there is, look on the opposite side and all the balljoints and control arm bushing. Shudder when braking could be badly warped rotors, loose ball joints (probably control arm ones), worn control arm bushing, or a caliper starting to lock up.

Will

The outer control arm ball joint was absolutely done!

I am going to be replacing the control arms tomorrow and going to check the brake disc as well.