Vibration when braking at highway speeds

[alms_lefko]

So I assumed my rotors were warped... Changed the front rotors and pads, there was still a good deal of life left on them.

Still getting a vibration when braking but only when I'm above 60mph.

Around town - no vibration.

What else would cause this!?

 

[DisguisedRope]

Could be your rear rotors, or a stuck caliper somewhere. Where all eight front calipers moving freely when you changed the front rotors/pads?

 

[alms_lefko]

Could be your rear rotors, or a stuck caliper somewhere. Where all eight front calipers moving freely when you changed the front rotors/pads?

I think you're right... I recall one of the pistons not retracting like the others... guess that was my sign then... :moping:

 

[thzpcs]

Did you lubricate all the sliders?

 

[DisguisedRope]

I think you're right... I recall one of the pistons not retracting like the others... guess that was my sign then... :moping:

I just replaced all my rotors and pads and found a stuck piston on my front passenger caliper. I believe it was the inboard lower piston. I replaced both front calipers because the pistons on the drivers side caliper looked like they could be on their way out as well. Replaced the rubber flex lines with new braided stainless ones because I had to bleed the brakes anyways, so I figured why not.

Also, be careful with the parking brake assembly in the rear if you change those rotors. My parking brake shoe retaining spring assemblies got messed up when I tried to force the rotor off without properly detensioning the parking brake, so I had to get a hardware kit and replace them. Only $15 bucks, but man is it frustrating trying to get it all back together with the small amount of working room in there.

 

[paraordnance]

It most likely the rotors. But not warped. There is no such thing as wrapped rotors, its a myth. What happens is brake pad material gets deposited on rotor unevenly and this causes vibration when applying brakes at high speed. The best way to avoid that is to properly season your newly installed pads and rotors.

 

[having fun]

You might check your LCA bushings, had the same thing you have and though the same on my rotors for 3 yrs.

Changed to poly at 105k. No more shakes.

Edit... Still haven't replaced my rotors or calipers.

 

[alms_lefko]

It was my drivers side caliper. Got one at Napa for $85. should I replace the passenger side as well... It's fine now, but who knows for how long?...

 

[alms_lefko]

I just replaced all my rotors and pads and found a stuck piston on my front passenger caliper. I believe it was the inboard lower piston. I replaced both front calipers because the pistons on the drivers side caliper looked like they could be on their way out as well. Replaced the rubber flex lines with new braided stainless ones because I had to bleed the brakes anyways, so I figured why not.

Also, be careful with the parking brake assembly in the rear if you change those rotors. My parking brake shoe retaining spring assemblies got messed up when I tried to force the rotor off without properly detensioning the parking brake, so I had to get a hardware kit and replace them. Only $15 bucks, but man is it frustrating trying to get it all back together with the small amount of working room in there.

So what's the trick with the rear? That's on this weekends agenda...

 

[TORCH]

It most likely the rotors. But not warped. There is no such thing as wrapped rotors, its a myth. What happens is brake pad material gets deposited on rotor unevenly and this causes vibration when applying brakes at high speed. The best way to avoid that is to properly season your newly installed pads and rotors.

what's the process of seasoning the new rotors/pads?

 

[DisguisedRope]

what's the process of seasoning the new rotors/pads?

The instructions that came with my powerstop drilled and slotted rotors/pads said to do 5 moderate to aggressive stops from 40 mph to 5 mph without coming to a complete stop and without letting the rotors cool in between. Then doing 5 moderate stops from 25 mph to 5 mph without coming to a complete stop but WITH letting the rotors cool in between. Not sure if its different for different rotor pad combos though, because the instructions on their website are even slightly different: Brake Pad Break-In Procedure | Power Stop
I went with the "Power Stop Z36 Truck and Tow Brake Kit" I have the smaller, 319mm front rotors so it was part number K138-36.

 

[DisguisedRope]

So what's the trick with the rear? That's on this weekends agenda...

This thread helped me a lot when I did it:

http://www.toyota-4runner.org/4th-gen-t4rs/166216-4th-gen-4runner-rear-brake-rotor-pad-diy.html

I got confused with the star adjustment because I didn't print out the thread and was following my Haynes manual. It says something along the lines of "insert screwdriver into lined up hole and adjust star upwards until fully retracted" to me that means click the front of the star up which is incorrect. what they mean is move the handle of the screwdriver up to click the star down like the following picture I found after I f'ed it up

I incorrectly assumed that the rotor didnt want to come off because it was a bit rusty, so i tried to whack it off with a rubber mallet. Don't do that if you don't want to spend hours trying to get little springs to go back in place haha.

 

[gm350reratliff]

I'm now going through this on my 4th gen. Shakes like the rotors are really warped but only when stopping over 60 mph. I just did the brakes last year with new slotted and dimpled rotors and pads. Calipers were not seized then and I don't believe they are now. All wheels spin freely, rotors are all about the same temp after a long drive (not hot at all), balljoints and bushings seem ok.

The other issue is, I can't find anyone to machine these rotors because they are slotted and dimpled. Also, I contacted the company who claims their rotors do not warp and they are don't believe they are warped but the only way for them to check is for my to send them in and let them examine the rotors. Well, that's great if I want my 4runner to sit for 3 weeks-yeah not going to happen.

Pretty surprised the rotors are like this because I do mostly rural highway driving and don't use the brakes much.

 

[alms_lefko]

This thread helped me a lot when I did it:

http://www.toyota-4runner.org/4th-gen-t4rs/166216-4th-gen-4runner-rear-brake-rotor-pad-diy.html

I got confused with the star adjustment because I didn't print out the thread and was following my Haynes manual. It says something along the lines of "insert screwdriver into lined up hole and adjust star upwards until fully retracted" to me that means click the front of the star up which is incorrect. what they mean is move the handle of the screwdriver up to click the star down like the following picture I found after I f'ed it up

I incorrectly assumed that the rotor didnt want to come off because it was a bit rusty, so i tried to whack it off with a rubber mallet. Don't do that if you don't want to spend hours trying to get little springs to go back in place haha.

Your pic didn't show...

 

[DisguisedRope]

Your pic didn't show...

Here's a link to the pic:

Imgur