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Causes of "Brake Shake" if not the rotors?

9K views 24 replies 8 participants last post by  Gaius 
#1 ·
My 99 4X4 shakes when I apply the brakes at off-ramp speeds. The higher the road speed, the more violent the shake. Below 40MPH, the shake is almost non existent. Stock wheels and 235-85 tires. It's done this since I got it 3 years and 45K miles ago. I seldom use the brakes, as it's an Interstate cruiser, so I haven't been hard pressed to fix it.

All 4 rotors have recently been replaced. The fronts about 8,000 miles ago and they helped, the rears last week, and they didn't help the shake at all.

The frequency seems too high to be a rotor(s). It's like driving over rumble strips. I can't really feel it in the steering wheel or the brake pedal. The pedal definitely does not pulse. Probably more on the front axle than the rear, as the dash and drink holders are where the shake shows up.

Any ideas? Thanks.
 
#2 ·
If they don't get used much, the rotor surface can get an "uneven" surface for braking where there's a slip & grab that will do that. Proper bedding-in is important when they're new, and you can actually re-bed them now! Go Smoke 'em up some...

I'd try that first, and hey! it's Free ;)
 
#3 ·
Update:

I really don't think it's the brakes themselves. There is NO vibration in the brake pedal. I reached down and felt it with my hand. No vibration.

And newest discovery: It barely does it in 4X4. I was in winter conditions yesterday in Northern California. I had opportunity to mess with the shake. Definitely is a lot better or non-existent when in 4X4.

I'm going to look at spring bushings, tie-rod ends, etc. It's really bad. Especially when NOT towing, because I can't use the trailer brakes for the majority of the braking.
 
#5 ·
Did you replace the rotors with cheaply Autozone or similar?

My wife's Toyota and my car would do same thing with cheap rotars.... I decided to try the pricey oem and even with cheap pads the shake was gone...

I even swapped back to the cheap Autozone ones and it would do it at high speeds. So then put back the pricey oem and the shake is gone.


I didn't feel my brake pedal vibrate either. Also did you get the rotars spun and then scuff up the pads with some sand paper?
 
#7 ·
Did you replace the rotors with cheaply Autozone or similar?
They came from a parts jobber, but they are Chinee. Probably the same part Vatozone sells. Right at $60 each, I didn't expect much, but machining is machining. If the faces are parallel, and runout is controlled....

I've installed hundreds of rotors on my personal cars, and professionally as a dealership mechanic. My experience has been that cheap rotors start out fine, but may warp and develop runout fairly quickly compared to OEM. And are sensitive to warping from uneven lug nut tightening with impacts.

My wife's Toyota and my car would do same thing with cheap rotars.... I decided to try the pricey oem and even with cheap pads the shake was gone...

I even swapped back to the cheap Autozone ones and it would do it at high speeds. So then put back the pricey oem and the shake is gone.
I saw this post recently. Interesting. I may try OEMs on the front and see if it makes a difference.

Also did you get the rotars spun and then scuff up the pads with some sand paper?
No. But again, on the hundreds of rotors I've installed, I haven't scuffed many of those either. I have had very few un-satisfactory results with my work over the 50-ish years I've been working on cars.

I DO break-in new pads and rotors now. When I did the fronts a few months ago, I broke them in. No issues, and replacing the fronts seemed to improve the shake a lot. When I did the rears, it was much more difficult to break in the rears because there is little braking at the rears. The fronts do 80% of the work, so they get too hot while trying to generate heat in the rears. I didn't want to warp the fronts while breaking in the rears.

I'll keep messing with it. I'm driving it 500 miles tomorrow back to Los Angeles on 395. Lots of opportunity to apply brakes from highway speed to township speed limits.

I would also like to put it on a 2-post lift in 4X4, spin it up and see if I can tell where the shake is coming from. Or if it only shakes when the suspension is dynamically loaded by braking forces.

Thanks for the interest.
 
#8 ·
i suggested that because your first post referenced rumble strip feeling which is common for bad needle bearings. Locking it in 4x4 makes the noise/feeling go away.

That's what noralph was suggesting as well when he said lock one side in at a time to see which is doing it
 
#9 ·
Ok. You guys are right, and I am wrong. I deleted my three posts above, rather than leaving incorrect clutter in the thread. My experience is with older Dana 44 and 60 type axles. The outer shell of the needle bearing is pressed into the spindle which never rotates, so neither does the needle outer shell.

I found this pic. The outer shell rotates with the bearing. The shaft does not in 2WD, so the bearing is "in play" in 2WD. In 4X4, all componets rotate at wheel speed, the bearing is NOT "in play". The exact opposite of what my experience was telling me.

Now I know. Please accept apologies for my ignorance.

 
#10 ·
Update 7/25/16

I replaced the front rotors with Ford, and the shake went away. Night and Day difference. It was GONE.

But now it's back with a vengeance. I've driven 7,200 miles in about 10 days of in-the-seat with my car and enclosed trailer in tow, and it shakes as bad, if not worse than ever. Very high frequency, ie, seems faster than rotor speed. Also seems to have a 'vertical' component to it, as the dash and cup holders shake violently up/down, compared to my seat, floor, or pedals (all fore-aft direction) which I don't feel it in.

I love this truck, but this dam brake shake that won't go away has me close to burning it. Hard to drive a truck that you can't use the brakes in because if you do, it just pisses you off. Not to mention un-safe because it's so violent, you don't use them when you need to.

Why did new rotors solve it for a couple hundred miles, but then it came back worse than ever?
 
#11 ·
And this is Only under braking?

If so, reread my "bedding" suggestion. What can happen is that the rotors surface gets contaminated (some pads do this more than others) and causes, not a "warp" the way is often misdiagnosed, but rather that Slip & Grab that makes you think of runout as being the problem. (and again, Free Fix so always worth a try) ;)

Other than that, you've checked all the fasteners? All the FE parts are pretty tight?
 
#12 · (Edited)
I'm familiar with "bedding". I did it on both the "old" brakes that shook, and these that shake after a couple hundred miles.

I drove the rig 1,270 miles YESTERDAY in one 20-hour stint. With the truck, car and trailer I'm at 13,500 GCVW. I had unexpectedly come to a complete stop from about 70 mph. The rig just didn't stop the way I expected it to (I later tried the trailer brakes, and they aren't functioning, that's why it didn't stop very well. I'm going to work on that today for the final leg of this 5 week trip), but it did by REALLY standing on the brakes. If THAT stop didn't "bed the brakes" nothing is going to. They still shake.

EDIT: Ralph: This is not a mild "annoyance". It shakes the crap out of everything. Seriously, if anyone was with me, they would get out and take a bus. It's REALLY bad. It's not the rotors, the pedal is smooth. If I knew how to take and post a video, I would. I've been working on cars professionally for 45 years. What ever is causing this, hasn't revealed itself yet. Thanks for the interest.
 
#13 ·
Can you get under it with a bar and go-over All the parts? Jack it up, spread the calipers open some, shake the wheels, lift the BJ's, the tie-rod ends, ALL the bushings in the springs, panhard rod & stabilizer, something's just got to be lose then I'd think...
 
#15 ·
Three sets of rotors, three sets of Ford pads over the past 20,000 miles, and the three sets behaved the same. Plus I've driven it 7,200 miles in the past two weeks, it can't be that the rotors "aren't clean". And the panic stop from 70 MPH @ 13,500 lbs with no trailer brakes got things plenty clean too.

I'm going to drive it for errands today. I want to try manually locking the hubs, see if that makes a difference; in an earlier post, I felt that the shake was diminished during 4X4 operation. That was with the last set of rotors and pads. I'm curious whether the spindle bearings may have something to do with this. Seems like the severity of the shake would require more mass in the components than front axle-shafts that aren't turning anyway could cause.

I'm also having trouble getting my head around something like ball joints, bearings, or other things because when the rotors and pads get changed, the shake goes away for awhile, but eventually returns. If it's something else, changing the brakes shouldn't affect the shake.

Thanks for the interest.
 
#16 ·
I'm also having trouble getting my head around something like ball joints, bearings, or other things because when the rotors and pads get changed, the shake goes away for awhile, but eventually returns. If it's something else, changing the brakes shouldn't affect the shake.
It's got to be one-or-the-other though, you can't have it both ways...

If you're sure that if you changed rotors & pads, right now, and it would "all go away for awhile", then you've certainly found your problem :wink[3]:

Are you saying you have just replaced them each time with the same product? You keep buying the same pads again and again???

If so, and as I said earlier, some pads are more susceptible to loading-up on rotors than others (maybe your driving style and use are incompatible with them).

Give ttyR2's suggestion a try (couldn't hurt) and go with EBC brakes & rotors (or something like that) next time if it cured it!
 
#17 ·
Locking the hubs made no difference.

The first set of rotors were on it for 100K miles. They were Chinee Power-slots that were drilled. They were badly corroded and deteriorated from 10+ years use in Colorado Winters. These were fine for years, but by the time I finally replaced them, they were beyond their service life. For cheap junk parts these were the best

The second set were Centrics from a local jobber with Ford pads. Again, Chinee rotors. There was still a bit of shake right from the get-go, which I assumed was the now very old and deteriorated rear rotors. I changed the rears, and the minor shake remained. By 18,000 miles on these, the shake was back with a vengeance.

Set #3 were installed 6 weeks ago. Ford OEM, direct from Ford. The pads were changed too again with Ford. The shake was gone for the first time in two years of owning this truck. It came back after a few hundred miles. This set now has 7,500 miles on it, all in the past 4 weeks. The shake is worse than its ever been.

I don't use the brakes much because this is primarily an Interstate cruiser towing my hobby-car in its enclosed trailer to events all around the country. I'm gentle on them when I do use them. It costs money to keep buying parts for it without any assurance that "this will be it". I'll figure it out eventually.

Thanks for the continuing input and suggestions.
 
#18 ·
I know this may be obvious but have you checked your alignment because that can cause it to shake when you brake...
 
#20 ·
You must not be breaking the brakes on correctly. When you are doing it and they are hot, DO NOT STOP. This causes brake material to adhere and cause vibration later on.

BTW, you can't warp cast iron rotors. You are feeling what's called DTV, and it's caused by not breaking brakes in right.

Sent from my SM-G930V using Tapatalk
 
#21 ·
You are feeling what's called DTV, and it's caused by not breaking brakes in right.
Thank you for this. I had to look up "DTV", and I found some very useful information and hints. The articles I found made no mention of "break-in" being a cause, nor even that break-in is necessary, but there were several insinuations that excessive run-out will cause DTV to develop.

Disc Thickness Variation (DTV) develops from excessive run-out (>.1 MM) that wears the rotor during non-breaking driving. Hence the shake develops after a period of time in service.

I have never checked the run-out with any of the new rotor installations. One of the hints I just read is "volcanoing" of the hub surface around the wheel studs can cause excessive rotor run-out. This truck over the years has had numerous seasonal tire changes, always using an impact gun. It also has its original bearings and hubs. There is a strong possibility that the hub surface is irregular, causing rotor run-out.

When I get back, and get a chance I'll check the run-out, and bearing condition. It will also give me an opportunity to service the needle bearings and ESOF hubs (which work, but are stiff manually). I may also investigate on-vehicle brake rotor machining, as that seems like a possible benefit for a problem-case like I have.

I understand that "bedding brakes" is important, I know there's more to it in this case than "improper break-in" because in 1.2 Million miles and literally dozens of sets of pads over 45 years on 30 different personal vehicles, I've never paid much attention to it, and never had a deal like my Super Duty. There's more to it than "I didn't break them in properly".

Again, thank you for the hint "DTV". This helps. Makes a ton of sense, and I now know how to check for it, and its root cause. (run-out).
 
#23 ·
I would also add torque sequince (with a torque wrench), and a drop of oil on the washer nuts. Also cleaning the crud from inside the wheels and hub surface. Clean, clean, and clean some more. Grease the pins every time it's apart. Anti-sieze on the wheel/hub interface, grease the ears on the pads to the clips.
*I think you have something else going on like worn suspension parts somewhere, but through the power of OCD with cleaning,lube, and proper assembly it can minimize problems. The slide pin bolts aren't all that much tourqe, but the caliper bracket bolts are something like when your right nut pushes out your belly button, with locktight...
I also open the bleader when compressing the caliper and vacuum bleed evert time. If "new" calipers get with new brackets and pins, once the old bracket - pins get frozen the heat cycle can't be good for that poor little bracket.
 
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