Has anyone anywhere any car ever figured out this problem

Hey all

A number of months ago there was a chap trying and asking what was causing the vibration when the brakes are pressed coming from the front end.
I have the same problem and it has been going on for what seems like ever no amount of rotor disc changes solve the problem it always comes back.
There must be a solution taking it to a specialist is an option but when they change the rotors AGAIN and not do anything else would be a huge issue


Any ideas anyone??
Thanks Lez

Worn lower control arm rear bushings will cause brake judder.

If changing the brake discs gets rid of the vibration then it must be disc related so I'd try getting the speed up and braking very hard a few times to get the brakes really hot then a gentle cruise to let them cool off.

I'm thinking that maybe there's an uneven build up of pad material on the disc due to gentle braking. I think sometimes they need a good working to keep them in order.

Take a look at my thread here.

EDIT: I'd warn about doing as Seatman says because I've done this twice with misbehaving brakes and it has made them WAY worse: if you look at the thread I linked to I posted a link to a picture of what this ended up doing to one of my car's rotors. It should not mess them up, but it did. I DO do this procedure (it's a bit more involved than just several hard stops) in order to bed-in new brakes: and it's produced excellent braking.

Lez,

What Fruitcake said. LCAs are probably original on your '04. That's 13 years old.

+1 on control arm bushings. When I changed mine, brake pulsating issues went away as a side benefit.

Brett

The problem went away initially for the OP and then came back. If it was related to the LCA bushings the problem would not have gone away at all (with changes to the brakes).

I'd still check and replace LCA bushings if they are done.

OP, what's your confidence in the quality of the brake jobs? Was the mating surface between the hub and rotor thoroughly cleaned and flat? Uneven surface will cause rotor run-out. You can have on-axle run-out checked. Were the guide pins removed, degreased, and re-greased? Sticking pins would be a problem. Replace flexible brake lines. Old lines can swell and block fluid flow. Rebuild calipers. Fresh seals are never a bad thing, and it's good to ensure the surface of the pistons are clean and not degraded.

Brett

If the problem went away with the installation of new bits then at some point all the other components would have had to have been behaving properly. The new bits changed the behavior. Why? And then the problem returned.

Lez, what pads and rotors did you purchase? How did you install? Did you break in the brakes? How? Give us some details, as without them you could readily repeat any errors: and it might be that that's all that's at issue here.

I'll note that after installing pads and rotors on the fronts of my car that I was quite disappointed not long after the install to hear a slight squeak coming from them as I drove along. I took everything apart and re-greased and it's been totally silent since (over 30k miles): my mistake was that I didn't use enough grease on contact points- I bought a large container of brake grease so I now am sure to not make that mistake again (of course, I'm NOT slathering all over the place- just enough on contact points).

Other things to check:

Ball joints at end of control arms.

Upper strut mounts.

The pins that the brake calipers slide on. (Loose or worn?)

Wheel bearings.

Uhhhh, that's all I can think of at the moment.

thanks for all replies

two sets of discs from different suppliers.. Occasionally problem will lessen or go away. When I brake hard problem is not noticeable. GENTLE lengthy braking produces the most judder.
Thanks Lez

One other thing to check. VW uses lug bolts instead of lug nuts, because they do this the rotor is held in place by a small Phillips head screw. So that when you're trying to put a tire on and line up the holes on the rim with the holes on the rotor it's a bit easier.

As anyone who has driven around in the salt belt knows those screws only last a few years and then break off. Occasionally they don't break off flush but leave a little bit of metal sticking up. Make sure if that is your case that the broken screw is flush with the hub so that it does not keep the rotor from sitting correctly on the hub.

lez said:

thanks for all replies

two sets of discs from different suppliers.. Occasionally problem will lessen or go away. When I brake hard problem is not noticeable. GENTLE lengthy braking produces the most judder.
Thanks Lez

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Please answer my questions, otherwise I'll spend my time elsewhere.

I vote for ball joints. Any creaking when turning?

Could be about anything. Flat spot on tire, alignment, tire out of balance, tie rod, ball joint, cv, strut, bad steering rack, bushings, crappy roads, wheel bearing, bent rim. Maybe even a worn dmf. I'd start with a tire balancing and work my way in; check runout on rotors and rims. Unless there is obviously other worn parts.

Never come across this problem in my 50 years ... slap on the discs pads and you good to go no braking in and all that stuff. Original rotors were getting a little rough so I figured I better change them.
The problem went away for a short while when I had my clutch replaced... several different wheels and tyres SAME...Everything with car works just fine....dosnt do it braking on curves? think I might take the control arm suggestion to heart and change them.

Judder can be caused by rotor disc lateral runout. Much information on it online. If the hub is not bent and there is not rust on the rotor to hub surface, the ultimate fix is to have the rotor cut on the vehicle as it gives you zero runout. I don't disagree that worn LCA bushings can make it feel worse, but ultimately to fix it you need to minimize that runout.


I have 2 mils of runout and judder that I'm fighting with. Called 4 different shops, none do on-the-car rotor turning. The VW dealer I called said they just got a machine in a month ago but they want $200 to just cut both rotors on the car.

Here's links talking about it.
From EBC
https://ebcbrakes.com/articles/how-to-solve-brake-vibration-permanently/


http://www.brakeandfrontend.com/rotor-runout-cause-and-correction/

This link is a 'test' for mechanics learning about brake problems but they give a good explanation of what's going on.
https://aviondemand.com/insider/ase-a5-test-prep-brake-pulsation-runout/

http://www.centricparts.com/files/technical guides/CommonCausesofBrakeJudder.pdf

Doesn't do it on curves… That is a dead giveaway to me that it is steering linkage, not rotors.

Trade Wind said:

Doesn't do it on curves… That is a dead giveaway to me that it is steering linkage, not rotors.

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Again, if the problem ceased after the new rotors and pads were installed then how could the steering linkage manage to cease acting up?

Not to bash the OP here, but I think there's something being lost in translation. Something is missing: I"d asked for very pertinent information and it was just brushed aside- troubleshooting without good data isn't really troubleshooting- it's guessing, which it seems we're all relegated to doing now.

OP, have fun tossing parts. I'm out of here...

lez said:

GENTLE lengthy braking produces the most judder.
Thanks Lez

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This is the exact situation when play in the suspension/steering will cause the pulsation. Under the low forces of gentle braking (i.e. bushings aren't fully loaded), the suspension can oscillate from one extreme of the available play to the other. Under harder braking, the loose part or parts get forced all the way to one end of their play and stay there until you stop braking so hard. No pulsation felt. This was my exact experience with spent lower control arm bushings. It's worth a front suspension refresh if nothing's ever been done under there. Control arm bushings, ball joints, and tie rods at a minimum. Strut mount stuff if you want to go farther.

Brett

Will start this weekend weather permitting anyone know of reliable testing to see what joints and bushings are worn? Will test for run out as well just dont know where I can stick the base
Thanks All

After fighting this issue and spending way too much money on it, I wanted to let you know I really appreciate the title of the thread.

lez said:

Will start this weekend weather permitting anyone know of reliable testing to see what joints and bushings are worn? Will test for run out as well just dont know where I can stick the base
Thanks All

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The rear control arm bushings should be obvious. If they're not the solid ones, you'll see the rubber is torn. The front ones are less likely to have issues. You can't really see them, but you could put a pry bar on it and see if there's excess movement at the joint. For the tie rods, disconnect the ball joint end from the knuckle and then push and pull on the rod. Feel for in-out play at the inner side when there should be none. I had around 1/16-1/8 in. of play on the tie rods. Ball joints you can put a pry bar on as well.

Again, if there's never been any suspension work done up front, just replace the bushings, ball joints, and tie rods altogether. Total parts cost isn't extreme for all of it (particularly if you're replacing the bushings instead of buying all new A-arms). Like others, I recommend the solid rear bushings. Much more robust for very little compromise (if any) in ride comfort. Don't buy Chinese made non-solid bushings. I tried some. They came apart in less than 10,000 miles. I went with solid ones after that.

Brett

I like knowing why I'm replacing parts that I'm replacing. So I test everything before replacing it.

If I was dealing with this issue, I'd first want to know if my rotors are warped. So, that means slapping a magnetic base on the steering knuckle (above the rotor and right where the strut joins up) and putting a dial indicator on the rotor. Use some M14 bolts to keep the rotor torqued down to the hub (the wheel bolts are too long and will hit the ABS trigger wheel).

If I find 'some' runout that I think is beyond acceptable, I'd remove the rotor and test the hub. Does the hub display roughly 1/2 the runout of the rotor? The hub is smaller, so the runout would be less pronounced closer to the center of the axle.

If no runout at all is found, then the rear control arm bushing would be up next. That's an easy visual check aided with a prybar.

Balljoint is also a prybar check. Tie rods, I like to separate them and check them by hand. Very easy to check for play that way.

Wheel bearings you can grab the hub and check for play. I haven't found this method to be super reliable, as I've had bad wheel bearings that you could hear but not feel. Confirmed bad after replacement made the noise go away, but on the car they 'tested' fine. I doubt this is the case for you since you make no mention of howling noises.

Lastly, if rotors are found to be warped, it isn't a rotor quality issue or massive braking effort, it's your brake pads hanging up somewhere. Whether a piston isn't retracting, pads not sliding on the carrier, or slider pins binding up... something in that assembly isn't doing the job. Inner vs. outer pad/rotor wear pattern will shed light on which component is likely bad. If the outer pad is untouched but the inner is badly worn, then the sliders aren't doing the job. If both inner and outer are worn, but more wear on the inner, possible the piston isn't retracting and the inner pad is always braking. Whenever I'm on the highway, I make a point of pulling over to a rest stop without using brakes at all, I lift off and coast to a stop. Then I touch all my brakes and make sure they are all ambient temp, or if I've planned ahead, I use my laser thermometer and check inner and outer rotor surface temperatures.

I just want to let all you folks know the problem with my brakes was finally solved after more than 2 years many discs pads and control arms and ball joints
Yes my control arm on the right was crap and needed changing and no my tie rod ends were perfect. IT TURNS OUT THAT DISC MATERIAL AND PAD MATERIAL IS CRUCIAL.........
After moaning and crying to the parts guy he told me that vw requires a disc with high nickel content and a metallic pad with no kevlar mylar carbon or any other ****e.
I was sold these high end metal sprayed rotors with special pad with brake in strips on the friction material and special compound on the pad back that
looked like felt. I suspected that pin lubricant was critical as well and after checking the WWW indeed it was especially with rubber slide pinguides I went with SIL- GLYDE.
Although I had went with good parts previously they wernt good enough I guess if Ihad got the stuff from the dealer this would NEVER have been a problem.
Lez

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Resolution post copied from other thread started by OP.