New Brakes New Shake

[BC240]

Hey,

I searched but didn't find anything too specific to my case.

Me and my friend just installed some new Bendix Pads and Stock Rotors(im a student). Everything was bled, cleaned and lubed up. Pedal pressure is good and it brakes good at city speeds but on the highway 90km/h ++ when I hit the brakes it shakes.. when i'm 150km/h it shakes quite a bit.

Before I rip my wheels off does anyone have ideas? My friend told me it could be the surface on the hub or something behind the rotor.. if it isnt clean it might have play and cause vibrations.

Thanks,

[g6civcx]

Did you install new OEM discs or did you reuse the ones on the car?

Did you bed the pads?

[BC240]

The Calipers? re-used.. My RL pad was at 0% and scraping metal which is why I changed em, all the rest had some meat. Maybe it was seizing.. I've never messed with brakes so this is all a little new to me.

[s14_mike]

check pads for uneven wear and check rotors for scarring. Are the rotors brand new? If not then see if you can get them resurfaced.

pedal vibration is usually due to uneveness somewhere between the pad and rotor

[BC240]

Originally Posted by s14_mike

check pads for uneven wear and check rotors for scarring. Are the rotors brand new? If not then see if you can get them resurfaced.

New Rotors, visually the rotors seem OK but I haven't taken the wheel fully off yet.

update: Just checked, all the rotors are smooth and i've done some heavy braking at highway speeds.. no warping or otherwise.

2 more things
#1 - its not pedal vibration its the car itself, no feedback through the pedal.
#2 - Bedding as in breaking them in? I just went easy on them for about 100km..

[g6civcx]

What you're describing sounds like heat warpage when the brakes heat up unevenly and develop hot spots. It could also be caused by the warpage (uneven wear) on the disc surface itself.

It could also be something not related to the brakes at all, like alignment, wheel balance, suspension, etc.

[BC240]

Originally Posted by g6civcx

What you're describing sounds like heat warpage when the brakes heat up unevenly and develop hot spots. It could also be caused by the warpage (uneven wear) on the disc surface itself.

It could also be something not related to the brakes at all, like alignment, wheel balance, suspension, etc.

uneven wear on the pads? is it possible to even this out? I didn't have this issue before so I doubt its unrelated to brakes.

[projectRDM]

If the caliper is seized you'd get uneven wear on the pads, as one side is compressing more than the other. That would cause a pull or unbalance as it's depressed. Depending on the wheel type you might have it slightly off center on the hub, though that's unlikely. You may also have warped the rotor from improper torquing of the wheel lugs or from overheating, either from the pads not being properly bedded in or the caliper sticking during driving.

[BC240]

Originally Posted by projectRDM

If the caliper is seized you'd get uneven wear on the pads, as one side is compressing more than the other. That would cause a pull or unbalance as it's depressed. Depending on the wheel type you might have it slightly off center on the hub, though that's unlikely. You may also have warped the rotor from improper torquing of the wheel lugs or from overheating, either from the pads not being properly bedded in or the caliper sticking during driving.

I have no pull at all.. maybe ill pull of the wheels and retorque them, my friend didn't use a torque wrench. I have 5-lugs on a 95 LE. I was hittin the brakes hard on the way home from 80km/h to a dead stop with 0 shimmy, its a bit bizarre.

thanks for help

[s14_mike]

hmm....brake pedals not vibrating, but instead it's the whole car when slowing down?
Sometimes when wheel weights are way off you get vibration usually through the steering wheel or sometimes possibly the whole car around 55-65mph. When you take off your wheels check to see if there are any missing wheel weights.
hope this helps

[g6civcx]

I would open the caliper and see if all the pads are seated correctly. Do a quick eyeball check and then torque down everything.

Make sure the wheels sit straight on the hub and torque down the lug nuts.


If that doesn't fix it then you're probably going to need pro help.

[300hp owen]

probably not the brakes, could be a tierod or similar suspension part that now is showing signs of wear because you now feel confident enough to push the limits so much?

or maybe not.

could be one of the rotors not seated flat against the hub surface, just a little spot of rust or crust can make them not aligned and perfectly flat. since that is also the surface the wheel mates to then your wheel is rotating a little off kilter too.

[sldbyuramg]

Originally Posted by BC240

New Rotors, visually the rotors seem OK but I haven't taken the wheel fully off yet.

update: Just checked, all the rotors are smooth and i've done some heavy braking at highway speeds.. no warping or otherwise.

2 more things
#1 - its not pedal vibration its the car itself, no feedback through the pedal.
#2 - Bedding as in breaking them in? I just went easy on them for about 100km..

bedding is not the same as going easy on them... i dont know your specific problem but i would suggest doing some research on what bedding brakes means

[98s14inaz]

I had a similar problem on my Kouki a long time ago. I had these heavy ass ROH wheels on there and the earlier azenis. I'd always get this shimmy in the front at highway speeds, checked alignment-ok, checked tire balance-ok, replaced tc-rods-helped a little, added hubcentric rings to my wheels-fixed the problem.

Bed the pads in properly too. It sounds like you didn't do that.

[redline racer510]

simple, you just forgot to resurface your rotors
you should always resurface your rotors when changing pads even thought the rotors dont look warped its still a good idea so that your pads wear evenly and no brake shutter

[heartagram]

sounds like your rotors. I had the same problem and my rotors were slightly warped.

[0wn3r]

I always use a wire brush and clean the hub off and apply a small amount of anti-seize around where the rotor touches the hub.

Then, make sure you're studs are torque'd down properly and you seat/break them in properly.

(i'm hoping you remembered to spin the rear pistons in and didn't compress them straight in..)

[projectRDM]

Originally Posted by redline racer510

simple, you just forgot to resurface your rotors
you should always resurface your rotors when changing pads even thought the rotors dont look warped its still a good idea so that your pads wear evenly and no brake shutter

You read like a piece of crab grass, he put NEW rotors on the car.

[BC240]

Originally Posted by 0wn3r

I always use a wire brush and clean the hub off and apply a small amount of anti-seize around where the rotor touches the hub.

Then, make sure you're studs are torque'd down properly and you seat/break them in properly.

(i'm hoping you remembered to spin the rear pistons in and didn't compress them straight in..)

Hub was clean and went on perfect, studs were torqued down properly (at the time) and pistons were compressed properly, im not even sure how you could press them straight in?.. either way it's a mystery right now.

I am taking all the wheels off Sunday with my friend and we'll see if everything is seated properly. Thanks for the help

[BC240]

Originally Posted by 98s14inaz

I had a similar problem on my Kouki a long time ago. I had these heavy ass ROH wheels on there and the earlier azenis. I'd always get this shimmy in the front at highway speeds, checked alignment-ok, checked tire balance-ok, replaced tc-rods-helped a little, added hubcentric rings to my wheels-fixed the problem.

Bed the pads in properly too. It sounds like you didn't do that.

I have been driving for over a week, Can I still bed them in? Also I am running stock wheels so I am not sure if hubcentric is needed.

[0wn3r]

Originally Posted by BC240

properly, im not even sure how you could press them straight in?.. either way it's a mystery right now.

haha..believe me, i'm sure there's been people that have some way or another

I think a week later of driving is a little late, usually it's a first-thing-you-do type of thing. you could always give it a shot though, but it almost sounds too late

[g6civcx]

Originally Posted by 0wn3r

I always use a wire brush and clean the hub off and apply a small amount of anti-seize around where the rotor touches the hub.

Then, make sure you're studs are torque'd down properly and you seat/break them in properly.

(i'm hoping you remembered to spin the rear pistons in and didn't compress them straight in..)

Best advice ever///

The rear pistons don't go in and out. You need a caliper tool or something to spin the piston.

[0wn3r]

Originally Posted by g6civcx

Best advice ever///

The rear pistons don't go in and out. You need a caliper tool or something to spin the piston.

you could do it w/ pliers, but MAN it's a PITA. definitely pick up the tool, i'm regretting i haven't yet as I need to put on new rotors as well.

[Jbma327]

I had the same problem with 2 of my car. On one of my car's the calipers were seizing up which is causing uneven brake pressure on the pads(causing vibration during hard braking). On my other car I replaced them with new Brembo rotors and new oem brake pads. The new rotors were defective which wasn't common from what I've heard =/ ... So I had them resurfaced and the vibration when away.


hope this helped