Help Diagnosing Vibration under Braking (1 Viewer)

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Irish Reiver

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Back in October I changed out my calipers, rotors and pads with all new OEM equipment. Since then i have done 2 coast to coast trips with some offroading thrown in for good measure (15,000 miles).

I now have developed a very noticeable vibration/pulsing when i am braking. Noticeable at all speeds but definitely worse at higher speeds.
I don't feel the vibration through the steering wheel which is leading me to suspect the rears. I did a quick visual today on the rears and even put a dial guage on the rotors but everything appeared ok. I pulled the pads and inspected them and they also looked ok.

Is there some way to isolate 1 corner at a time to see if the issue goes away? I have some local roads that i could test it on without endangering myself or other.

Any suggestions would be greatly appreciated.
 
Sounds like a sticky caliper has warped a rotor.
Did you grease the caliper slide bolts at install? Did you use new slide bolts? (slide bolts...can't think of proper term for them at the moment) The Permatex type is green, iirc.
 
Sounds like a sticky caliper has warped a rotor.
Did you grease the caliper slide bolts at install? Did you use new slide bolts? (slide bolts...can't think of proper term for them at the moment) The Permatex type is green, iirc.
Remember these were new OEM (not reman) calipers 5 months ago. Slide pins were greased with the Toyota brake lube on install and were sliding freely when i did my visual.
I also suspect a warped rotor but i didn't pick it up using the dial guage.

Would a brake hose clamp on the soft line allow me to disable that corner or would the fluid just push past the clamp?
 
First step i do on any drive vibration is rotate tires. IF you have a single caliper that warped a rotor then the vibration should change. If it doesn't then you have ruled out the rotors and any tire issues.
 
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I recently redid my brakes with new Brembo rotors and Yellowstuff pads. I'm happy with the result. I did the work because I was getting some intermittent vibration that was pretty severe. Having completed the rotor swap, I don't think the rotors were the problem - they are dead flat with very low measured runout (DBA slotted w/ 30k miles). I was however running the 100 series pads on the 80. The pads are larger than the 80 pads and actually hang over the edge of the disk. As the pads wore down, it created a ridge on the pad that made contact with the outside edge of the disk. I think that may have caused the vibration. If I hadn't already replaced everything, I would cut the ridge off of the worn pads to see if that fixed the vibration.
 
It could be pad transfer. Hot pads literally melting from heat and transferring to the surface of the rotor.

It was a common issue with my 2002 Nissan Maxima. Ceramic OEM pads would overheat with normal driving and stick to the rotor. Machining the rotor was only a temporary fix. Lots of folks blamed it on warped rotors but after switching to Hawk pads and later Akebono pads, I never had a problem again.
 
First step i do on any drive vibration is rotate tires. IF you have a single caliper that warped a rotor then the vibration should change. If it doesn't then you have ruled out the rotors and any tire issues.
Help me understand how rotating the wheels helps rule out a warped rotor? My brain can't process that idea at the moment. Not being snarkey just inquisitive.
 
Help me understand how rotating the wheels helps rule out a warped rotor? My brain can't process that idea at the moment. Not being snarkey just inquisitive.
The torque on the studs can affect a rear rotor and warp it due to incorrect torque pattern. (To answer your question back to @REKCUT ) I have had a tire shop do this to one of my vehicles by just slamming it on, hitting it with the impact and not doing a star pattern. It won't do it on the fronts because they are inboard rotors.

I was going to suggest the parking brake. I have accidentally had my parking brake pulled up a couple notches and the shoes caused it to chatter hard. It took me a couple miles to figure out what it was. Maybe you have a rear shoe that has come loose or something, or maybe the handle is down, but the cable is not releasing and the parking brake is still engaged?

Before I rebuilt my parking brake mechanisms, I had to get under there with a hammer and force them to release after I used it.
 
Thanks for the reply. I am the only one who has removed/replaced my wheels. Always torqued and always a star pattern. :cool: I think I can rule out the parking brake (was able to spin the wheels when using the dial gauge checking for rotor runout.
 
Thanks for the reply. I am the only one who has removed/replaced my wheels. Always torqued and always a star pattern. :cool: I think I can rule out the parking brake (was able to spin the wheels when using the dial gauge checking for rotor runout.
I have also had my rotors warp or create vibration after being installed for a while.

Typically I will re-bed the brakes and that solves it most of the time.

If I have hot rotors from a drive, then hit a large puddle, sometimes that can warp them as well. Re-bed and see if that cures it.

I would not place a clamp on the hose because that typically can damage a hose.

You could drive down the left side of a paved road, drop the left side off to a gravel shoulder to brake hard and see if it pulls or slides, then do the same for the right.

Since you ran a dial indicator on the rotors, what about the LSPV arm or chattering inside the valve? Or did you remove the LSPV?
 
Help me understand how rotating the wheels helps rule out a warped rotor? My brain can't process that idea at the moment. Not being snarkey just inquisitive.
You mentioned that you felt like it was coming from the rear of the truck. If you have one or both of your rear rotors with warping and you rotate the tires then the vibration should move to the front. If it stay the same and you feel no change then you can pretty much rule out tires, wheels , and rotor.
 
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Before I rebuilt my parking brake mechanisms, I had to get under there with a hammer and force them to release after I used it.
so you spent all that money when you already had a hammer? ok Money bags just throwing money at the problem..
 
If you have one or both of your rear rotors with warping and you rotate the tires then the vibration should move to the front.
Eh...OCD kicking in. A warped rotor does not move when the wheel/tire does. A warped rear rotor will still be a warped rear rotor regardless of rotating tires.
I'll assume I'm just misunderstanding.
 
It's possible to have a harder section on the rotor. This happens when rotors are hot and then coming to a stop and having to hold your foot on the peddle. The rotor then cools diferentially resulting in firmer spots..... not always a problem and can be turned /machined out when it happens. Rotors may not appear warped but vibration can occur
 
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Check that your e-brake isn’t sticking or dragging. If it is that will heat up the rotor and cause a vibration.
Did that and it's definitely not catching, dragging or sticking. Most of the parking brake assembly is fairly new.
Eh...OCD kicking in. A warped rotor does not move when the wheel/tire does. A warped rear rotor will still be a warped rear rotor regardless of rotating tires.
I'll assume I'm just misunderstanding.
Thank you. I have struggled with this also 😆
 
Eh...OCD kicking in. A warped rotor does not move when the wheel/tire does. A warped rear rotor will still be a warped rear rotor regardless of rotating tires.
I'll assume I'm just misunderstanding.
Ok, So too many late nights and a couple of unexpected repairs and I wasn't thinking straight. Rotors do not move. I still always rotate tires on a vibration just to rule out wheel and tire issues as a cause. Sorry for the misinformation .
 
Did you check your wheel bearings? Prob where I would start since everything is new
 

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