Brake pedal vibration only when braking at high speeds

So I replaced the caliper pins and greased them up again. I feel like I’m getting less vibration. Not sure if it’s gone. What would you do next? Change the rotor or caliper?

Did you check the flange for rust?

Tester

I didn’t take off the bracket. I guess that’s an easy free check tomorrow morning.

Myself, I’d check the rotor’s runout next, as mentioned before
(pencil and block). I would check both sides. That will tell you
if either is warped. If warped, there should be some local shop
that can test if it can be turned down, or if it requires
replacement. My local auto parts store does this, but you may need
a brake shop. The rotor(s) are off (supported on a bit of coat
hanger, so it’s time to replace or repair them. Check your pads
and take a best guess if they are “burned” bad enough to need
replacement.

  Yes, I forgot to mention lubing the pins. If they bind it can

cause dragging, as well.

If it’s still pulling to the left is it a tell tale sign that it’s the right front?

It’s pretty easy for a diy’er to check the run-out. Figure out a way to position the tip of something sharp (like a pencil) as close as you can to the rotor surface, but without touching it. Then hand rotate the rotor. The distance between the pencil and the rotor surface should stay nearly the same all the way around. 2 mils is the typical maximum allowed run-out for brake rotors. The thickness of the metal in a beer can is about 4 mils for comparison.

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With the car up and wheel off the rotor is loose. How do I judge the play then?

I’ve never experienced that problem before, as the rotor is usually stuck fast to the hub by both a separate fastener and rust. Stuck rotors are more of a problem for me than loose rotors. That may be a clue btw. You may have to figure a way to hold the rotor tight to the hub using the lug nuts & maybe washers.

Another idea, maybe the wheel installation procedure is warping the rotors. When you install the wheel do you torque the lug nuts in the correct sequence, and in rounds of three. So for example if the lug nut torque spec was 90 foot pounds, you’d torque them all to 30 first, then to 60, then to 90. That method helps prevent slight warping of the rotors.

Put the lugnuts back on (without the tire) to secure the rotor to the hub to measure the round out. I’ve had to put some lug nuts on upside down to do this.

Before getting too crazy into brakes for the pulling issue, try switching the front tires to the opposite sides of the car and see if the pulling changes sides. Ive had this happen with brand new tires.

We have rotated the tires. Still pulls. Lug nuts are the closed kind. :grimacing:

Like mentioned earlier, next time you drive and its up to its tricks stop after awhile and feel both front wheels. If one is significantly hotter that is your problem. Did you ever replace the caliper?

Rotors warped shouldnt cause pulling unless its only pulling when braking…even then it seems a bit much. If your pedal is pulsating just bite the bullet and get some new pads and rotors (or just rotors if you already got new pads on there). Also, make sure youre not missing and clips or anything. Put the car up, put new rotors on, then push the pistons in to re-install the pads. Pad wear should be about the same on both sides of the car. Make sure you out a little bit of caliper grease on the tabs of the brake pads where they ride in the caliper bracket. Again, this will take care of the pulsating, but the pulling needs further investigation.

It is more likely to be the left when going down the road (no
brakes applied), then it’s more likely to be the left. There is no
guarantee, though. It could be something else causing it to
pull… and the off side could be close to fail.

Got the rotors off right now and they dont show much signs of rust on the hub or the rotor or the rim itself. I brought them to the auto parts store and they confirmed with a caliper that the rotor was not out of spec. The next test I guess is to get it back on the hub and see if it runs in or out. Do I put the car in neutral? The rotor does not turn with it just parked…

I just replaced the brake pads on the front both sides. They actually sent the wrong size that I didn’t double check from rockauto and installed them. It formed a lip on the outer most edge. I replaced them with the correct size and will test it on the highway tomorrow. Hopefully that was the fix!

Update with no resolution yet :frowning: I replaced the rotors and pads with the realization that the hardware from the new set was not compatible with my car. So new brakes/rotors on the front and new drums/pads on the back and still getting the wobble just in the brake pedal when hard braking above 40mph. I also cleaned the wheel hub down to metal before I put the new rotors on so that shouldn’t be an issue. What next? Could it be the back brakes? Front calipers? Any ideas please!

Theres another thread on here about Wagner rotors warped out of box. I had a set of OEM GM rear drums warped out of the box. Then put on new Carquest drums. Still the same. What the heck? I must have done something wrong. I ended up taking to a very trustworthy shop who indicated that indeed the new drums were warped right out of the box. So, they turned them and away I went with great brakes. I sent the bill to Advance Auto who paid me back the 100 bucks (after some arguing). This is why its getting nasty to do DIY brake jobs. You can easily get warped parts right out of the box. The mechanic told me he turns everything he installs, even brand new. You now have all new brakes all around. This isnt a bad thing, but it is frustrating. So, if it were me I would check the yelp ratings for independent mechanics and take it in to have him take a looksy before throwing more at it. He can check stuff for out of round and make things true in ways you and I can’t.

Yah at this point I am about ready to give up. I am starting to wonder if it isn’t the rear drums that are out of round. Would that make sense only at higher speeds. Do they not engage (being a fwd car) unless needed more than just stop and go traffic?

They always engage…I too am past the point of speculation. You have done everything I would do. I would take it to a highly regarded shop. 5 will get you 10 they are warped out of box.

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