Virbations when braking from high speeds.

[Seraphim.312]

I'm noticing i'm feeling shaky vibrations when braking at high speeds on my driver side front wheel. I'm not sure it its the CV joint or Wheel bearing.

Does anyone have any ideas? 2016 SHO

 

[yaycandy]

Brake hoses fail on this platform alot. I just had to change my left rear pads out for the same reason. They were wearing unevenly. Other side was still good. Just put the pads on a couple months ago. So check your pads, even if they are newish

 

[jman1200]

CV joint will vibrate under load, when accelerating, so no.
Wheel bearing is unlikely to cause vibration, will be making lots of noise before that.
Your issue is most likely brakes, as said it could be the hose or you need to reseat your brake pads. Many people might say "bent rotors" but over the last year I've been reading a lot of articles about this and it appears that all you need to do is repeat the pad/rotor seating procedure (assuming rotors and pads are in good shape).

 

[Seraphim.312]

I just did my brakes about a month or two ago, so I'll def check it out. I do notice there is a droning sound when the car coasts down from high acceleration in the same area, would that still be the brakes?

 

[yaycandy]

I just did my brakes about a month or two ago, so I'll def check it out. I do notice there is a droning sound when the car coasts down from high acceleration in the same area, would that still be the brakes?

not sure on the miles you have on the car but a collapsed brake hose would cause them to drag. Even a little bit would cause a drone sound and glaze the pads.
Really there is alot of different answers for this but checking the brakes and hoses is the easiest. Its hard to check the bearing on the rear because of the multilink. You cant have full droop to check like the old days. You need to pressure off the wheel and then jack up a certain point on the suspension to check bearings on this platform. I saw a vid somewhere but its better to have Ford check it out if the brakes are fine and still droning

 

[Seraphim.312]

I may just need to take a look myself, but some braided steel hoses might fix that issue you are referring to right?

 

[yaycandy]

I may just need to take a look myself, but some braided steel hoses might fix that issue you are referring to right?

Yes

 

[stripSHO]

I just dealt with a collapsed line on the front right of my f150 three weeks ago. Shook the truck so hard going down the freeway that all the change in my cupholder was splashing around. BUT the vibration only really occurred after I let off the brakes, not while actively braking. The problem wheel was really easy to spot with an infrared thermometer; I think that rotor was like 660 degrees by the time I got home and even the wheel itself was too hot to touch.

My SHO has developed a significant rumble at high speed braking, a light pulsing under low speed braking, and a faint tick while driving that is in rhythm with vehicle speed. I assume I have a rotor ******* up, but I've been so frigging busy lately that I haven't bothered tearing into it yet. I've probably only driven the car 500 miles this year so I'm not overly concerned about it yet. But I'm excited to see what you come up so that hopefully it will cut down on my diagnostic times!

 

[stripSHO]

Wow they censored scr ewed. This is way out of control.

 

[stripSHO]

I may just need to take a look myself, but some braided steel hoses might fix that issue you are referring to right?

If you think a brake is dragging, do this:

1) Take the car for like a 5 or 10 minute drive with at least a few stops in the mix. Just normal driving is fine. A couple firmer stops might help, but no need to do full brake skids or anything. Then go back and immediately check the temp of your rotors with an infrared thermometer. They should all be roughly equal in temperature and I'm gonna say, less than 200 degrees. If one is drastically different from the others then it's probably dragging. If you've got multiple rotors at 250+ degrees then probably more than one problem exists. In my case I discovered in addition to a faulty hose up front, both my rear parking brakes were hanging up after just recently using them.

2) Jack up the suspect wheel.

3) Verify the wheel spins freely. If it has a lot of rolling resistance even though the brake pedal hasn't been touched in a long time, then your problem is not likely to be hydraulic so you might stop here. Caliper seized or something else mechanically wrong.

4) Give the brake pedal a good press and release then see if the wheel still rotates as easily as before. If it does, that brake isn't dragging. If it becomes difficult/impossible to move, then you know you're at the right spot. Go ahead and remove the wheel to get it out of your way. Once off I'd recommend throwing a couple lug nuts back on to hold the rotor in position and to give you a place to put a wrench for a bit of leverage when trying to spin it.

5) Pump up the brakes again, and crack open the bleeder on your caliper. If the wheel does not immediately free up then your caliper is shot. If it does begin to spin easily then close the bleeder and move on to the next step.

6) Pump the brakes again, and loosen the connection where the flex hose meets the hard line until fluid starts to leak out. If the wheel frees right up, then the hose is bad. Most likely you won't have to go any farther than this. But if that doesn't do it then retighten the fitting, find the next fitting upstream, pump the brakes again, loosen that one, etc. If there's a blockage in a line you'll be able to positively identify which section to replace this way. If you make it all the way to the ABS controller (or whatever the line eventually goes to) without being able find the restriction then it's time to crack open the service manual and go from there.

 

[rubydist]

Sometimes the new rotor will warp and that will cause the symptom you report as well.

 

[RonPorter]

Rotors don't warp. Ever. It's a brake pad issue, most of the time. It could be a CV, but that would be also on acceleration.

 

[stripSHO]

Rotors don't warp. Ever. It's a brake pad issue, most of the time. It could be a CV, but that would be also on acceleration.

Saying rotors don't ever "warp" is technically true but also mostly semantic.

Solved: The Mystery of Warped Brake Rotors

www.mechanic.com.au

 

[rubydist]

I guess we have to agree to disagree on that, because I know for a fact that brake rotors warp. Sometimes the warping is causes by pads not releasing properly, but there are several other reasons including poor casting quality that have nothing to do with pads.

 

[SHOrod]

If you're noticing the vibrations only during high speed braking, and it is no longer felt if you release the brake pedal, that indicates an issue with one or more brake rotors. If the vibration can be seen in the steering wheel, at least front brake rotors are involved. If it's only noticed in the chassis/seat, then it's likely limited to rear rotors. It might be due to improper torquing practices of the wheel, it may be due to glazing of the rotors, or it may be due to runout of the rotors.

As someone who spent several years of my late childhood working at my dad's auto repair shop and specializing in brakes, I can say with confidence that rotors definitely do get runout issues, often referred to as "warping." I have hundreds, if not thousands, of hours running a brake lathe and was trained to start with a 0.003" cut on both friction surfaces of the rotor. That light of a cut often showed surfaces that were not true. The surfaces were often also not parallel, which I suppose could suggest that the rotors are not truly warped, but it was definitely not just due to glazing of the friction surfaces.

A collapsed brake hose may contribute to glazing, which can cause vibration when braking, but as mentioned by stripSHO, this will almost always result in dragging brakes and therefore the vibration would likely not go away immediately when the brake pedal is released, and can typically be diagnosed by checking for exceptionally hot brakes/wheels after driving. If the mechanical components of your brakes are otherwise working fine (aka caliper slide pins), a collapsed brake hose will not cause uneven pad wear since the hose by itself will not effect the floating ability of the caliper. The excess heat generated though, over time, may cause the brake grease to get gummy and prevent proper floating of the caliper, but just replacing the hose will not remedy uneven pad wear by itself.

-Rod

 

[Seraphim.312]

If you're noticing the vibrations only during high speed braking, and it is no longer felt if you release the brake pedal, that indicates an issue with one or more brake rotors. If the vibration can be seen in the steering wheel, at least front brake rotors are involved. If it's only noticed in the chassis/seat, then it's likely limited to rear rotors. It might be due to improper torquing practices of the wheel, it may be due to glazing of the rotors, or it may be due to runout of the rotors.

As someone who spent several years of my late childhood working at my dad's auto repair shop and specializing in brakes, I can say with confidence that rotors definitely do get runout issues, often referred to as "warping." I have hundreds, if not thousands, of hours running a brake lathe and was trained to start with a 0.003" cut on both friction surfaces of the rotor. That light of a cut often showed surfaces that were not true. The surfaces were often also not parallel, which I suppose could suggest that the rotors are not truly warped, but it was definitely not just due to glazing of the friction surfaces.

A collapsed brake hose may contribute to glazing, which can cause vibration when braking, but as mentioned by stripSHO, this will almost always result in dragging brakes and therefore the vibration would likely not go away immediately when the brake pedal is released, and can typically be diagnosed by checking for exceptionally hot brakes/wheels after driving. If the mechanical components of your brakes are otherwise working fine (aka caliper slide pins), a collapsed brake hose will not cause uneven pad wear since the hose by itself will not effect the floating ability of the caliper. The excess heat generated though, over time, may cause the brake grease to get gummy and prevent proper floating of the caliper, but just replacing the hose will not remedy uneven pad wear by itself.

-Rod

Thanks for this, So going back to the improper torquing if I torque the wheel nuts to tight? or the brake caliper after changing, im guessing that could be the cause from what you are saying. I normally don't tight the nuts super tight but just tight enough so they can't get loose if that makes sense? I just got the new front rotors but they do look like they are forming "rings" from the brake pads, I imagine it might just be one of the calipers acting up so I'll need to to test them this weekend and get a new caliper slide and possibly getting the surface of the rotor machined

 

[RonPorter]

The rotors themselves do not warp. Period. How many article links do you want to see from brake experts on that.

This myth has, across every car group I'm in, caused people to attach some mythical power to brake rotors, and they way overspend on the drilled/grooved/slotted/sprinkled with pixie dust overpriced carp, when their problems are from the cheap *** pads they get. Which even includes factory pads. People buy the high dollar brake kits, they believe these new rotors "fixed" their issues, when really the better pads that came in the kit are what actually fixed their problem.

The issue is pad deposits on the rotor, which yes, can manifest itself by appearing to be "warping", because of the uneven surface.

Years ago, the generally accepted myth about SHO brakes, with the 10.2" rotors, is that those rotors were constantly "warping". Not true. Back about 10 years ago, I put Carbotech XP10/XP8 pads on the stock rotors on my white 89 SHO. I then proceeded to run VIR at the 2011 Charlotte Convention, and Brainerd (BIR) at the 2012 White Cloud SHO Convention. Both of these are long, high speed tracks. This was running in my usual Advanced/Instructor Class. Guess what? ZERO brake issues, and the brakes worked flawlessly. At the time, these were $350 pads for the set, and the rotors were the cheapest blank rotors I could find at Rock Auto (IIRC, maybe $20-$25 each).

It's the pads, folks. Not the rotors. If you aren't spending over $100 for a set, they're cheap soccermomobile parts store pads.

FWIW, just got a full set of Carbotech XP10 pads, for running PittRace at the 2021 SHO Convention over Labor Day. I needed new front 15.35" rotors for my 6-piston Brembos, but the pads, at $567, were more expensive than the rotors.

Spend your brake money for what matters, not what the traditional myth tells you!

 

[rubydist]

Well, you will have to explain that to the guys who resurface brake rotors every day that take more off one side than the other because the rotor is warped. I've seen it enough to know its not often caused by pad residue. This is reality, not myth.

 

[stripSHO]

Guys this is a troubleshooting thread. I don't see how arguing the universally accepted colloquialism for uneven rotor surface, aka warping, helps anything here. Yeah whatever, maybe poor pads are to blame, maybe the brakes didn't get a good bedding, maybe she was rode really hard and put up wet, I don't know. But the bottom f*cking line is that here in realityville 99 out of 100 times brake pulsations are from wArPeD rOtOrS. And it won't matter if you buy $350 pads or $1000 pads because once the damage to the rotor is done and it isn't going to magically go away anytime soon just by unnecessarily slapping fancy race pads on a commuter car. Get the rotor turned, use whatever pads best suit your driving habits (which for most of us is [gasp!] cheap pads), give them a proper bedding and move on with life. If anything I've said is wrong or ignorant, feel free to correct me. Or, just postulate about how many links you could theoretically post to correct me without actually doing anything.

Btw Ron I'm sure F1 teams around the world are now throwing away their $50k carbon fiber rotors on the news that it's all just pixie dust and they can get the same performance with a 10" sho rotor.

 

[jman1200]

After reading some posts, I am never going to mention how much I usually spend on brake pads... I feel disgusted to realize how cheap I am... lol !