Warped(?) rotors... again

Even new brake rotors, after 1000 - 1500 miles makes me a problem, can't brake normally, the steering wheel is vibrating awful, I feel the brake pedal is vibrating, too! It happens above 50km/h speed. Last year I bought Brembo rotors (and TRW brake pads, caliper pins greased w/silicone grease)... same thing . Got them machined and after 1500 miles it happened again... Ten years I can't find out what's going on, I'm tired of this...

These are the fronts only? Both sides?

Who torques the wheel bolts?

Time and time again.... odd. Things work well for 1500 km or so?

Are you sure a caliper isn't sticking? I put new pads and brakes on back in '06 and have not had an issue so far. The past 2 years has put some major stress on the braking system too...

You may have a sticking caliper, this can be caused from several things including too much grease. It's possible the caliper is not retracting properly, it only relies on the piston seal for this, and the pad gently rubbing on the rotor will cause a thin spot. Once you apply the brakes the caliper sees that transition from thick to thin and back causing a pulsation.

If you don't want to spend time tracking it down it may be worth just buying a pair of calipers. Otherwise you can measure the brake plate to brake plate distance with a vernier micrometer in a dozen places radially (like hour positions on a clock) and look for a total variation of more than +/- 0.0015".That's not a hard and fast number, post your results if you go that route.

Are your LCA bushings good? Just something besides the obvious places stated above.

If the problem is occurring on both front rotors I would suspect the master cylinder before the calipers.

Be sure and check your lower caliper pins on both sides. If they seize up they could be contributing to the problem.

Steve

Maybe this thread can give you some insight?
http://forums.tdiclub.com/showthread.php?t=426733&highlight=brakes+102

Thanks for replies, guys.
1. Front brakes only (rears are drums), always for 1000-1500 km.
2. Wheel bolts torqued properly, 110 Nm.
3. Caliper isn't sticking. Pins lubed properly with (not too much) silicone grease.
4. All the suspension bushings and other items, including tie rods and bearings,
replaced a few months ago.
5. What could be wrong with the master cylinder?
6. I'll take in consideration mishkaya's link, so we'll see...
----------------------------------------------------------------
A guy who machines rotors and drums for 30 years, told me that the problem is
in the rotors itself. The material they are made of is very "caprice", so after the
manufacturing, they shouldn't be in use at least one year, because metal is "still
working" inside and it needs time... He advices me to machine old rotors (although
they are 11mm thick (13mm is proper thickness, that's why I bought new ones - and
because of the vibrations...), so we'll see. The new ones will "rest" for a year. I hope
everything will be ok... I hope...

I think I found out what was driving me crazy last ten years...
I changed the rotors, put the (machined) old ones on and after 1500 miles I have a slight vibrations while braking, not the "earthquake" like before Why? Well, I have inspected and tested EVERY piece of the front brakes veeeery carefully and found out that the left upper caliper pin is slightly bent and doesn't fit full length in the caliper hole (some 6 - 7 mm is out), so it gets stuck after a while... that's why my outer brake pad is (always) worn out 50% while the rest ones are only 20% (and the wheel is always slightly warmer than the other one)! While replacing the rotors I turned the pin, as much as it was possible, on the position that will not stuck in the caliper hole (I had no spare pin at that moment). So, the result was less vibrations! Now I'm going to buy a pin (already found one) ...maybe I should also buy the outer caliper (the part where pins go)?
Well, in near future (when I get some time off) I will machine Brembo rotors and I'll buy new pads and I think I'll have nice, strong and vibration-free braking. Thanks for the suggestions.

Solved!!!

No, I had not "...nice, strong and vibration-free braking...". The vibrations got back after, of course, 1000 - 1500 miles. Sigh, what to do? Rotors machining again... Done, but...!!!... this time rotors were machined ON the car, I didn't take them off! And guess what - 3000 miles, and car brakes w/o even the smallest vibration! So, after a looooong time I (?) solved this pain in ...! And I think that the problem is in the hubs, too. Take into consideration this, guys. Good luck.
(Happy, happy, happy).

LLL said:

No, I had not "...nice, strong and vibration-free braking...". The vibrations got back after, of course, 1000 - 1500 miles. Sigh, what to do? Rotors machining again... Done, but...!!!... this time rotors were machined ON the car, I didn't take them off! And guess what - 3000 miles, and car brakes w/o even the smallest vibration! So, after a looooong time I (?) solved this pain in ...! And I think that the problem is in the hubs, too. Take into consideration this, guys. Good luck.
(Happy, happy, happy).

Click to expand...

That is your problem. Your machinist is just taking your money for something you don't need.

VW rotors are made with such little extra material that turning them results in them being under limits and warping in service. When you install new VW rotors do not have them turned.

LLL said:

A guy who machines rotors and drums for 30 years, told me that the problem is
in the rotors itself. The material they are made of is very "caprice", so after the
manufacturing, they shouldn't be in use at least one year, because metal is "still
working" inside and it needs time... He advices me to machine old rotors (although
they are 11mm thick (13mm is proper thickness, that's why I bought new ones - and
because of the vibrations...), so we'll see. The new ones will "rest" for a year. I hope
everything will be ok... I hope...

Click to expand...

Sounds like hogwash to me Especially the recommendation that have your already undersized rotors turned. I think he just likes to turn rotors.

The machinist is ok. When he does other clients rotors, they are ok,
no complains from them. When he does mine, they are starting to
vibrate after some amount of miles... Why? What about hubs? Don't
you think that hubs are the problem? (Before I did the on-the-car
rotors machining, I've told a mechanic, kind a friend of mine, about
my brake problem. He listened very carefully and after I finished, he
said: change both hubs! The end!). And, these rotors were first ones I
have machined before installation. So, for me there is no doubt where
is the problem. Especially now, when the problem is solved.
P.S. Does "turned" mean "machined"?

LMAO @ turning the tiny rotors on a B4 Passat 4cyl....

Your REAR brakes may not be working properly either. Unloader valve on rear beam stuck and/or full of crud, sticking shoes and/or wheel cyl pistons, etc.

Do you have vented front rotors? With rear drums I can't remember what they used up front but some cars got the solid front rotors.

Steve

LLL said:

The machinist is ok. When he does other clients rotors, they are ok,
no complains from them. When he does mine, they are starting to
vibrate after some amount of miles... Why? What about hubs? Don't
you think that hubs are the problem? (Before I did the on-the-car
rotors machining, I've told a mechanic, kind a friend of mine, about
my brake problem. He listened very carefully and after I finished, he
said: change both hubs! The end!). And, these rotors were first ones I
have machined before installation. So, for me there is no doubt where
is the problem. Especially now, when the problem is solved.
P.S. Does "turned" mean "machined"?

Click to expand...

You need to read and comprehend my first post.

Ol'Rattler said:

VW rotors are made with such little extra material that turning them results in them being under limits and warping in service. When you install new VW rotors do not have them turned.

Click to expand...

"You need to read and comprehend my first post."
So do you!... my previous. I'm not in the mood
now to prove something obvious. I'm off - click!
oilhammer, I have drums rear.
No, Steve Addy, I have solid rotors.

LLL said:

"You need to read and comprehend my first post."
So do you!... my previous. I'm not in the mood
now to prove something obvious. I'm off - click!
oilhammer, I have drums rear.
No, Steve Addy, I have solid rotors.

Click to expand...

I had wondered about whether you did or not. I would definitely be upgrading to vented 10.1" front rotors! I'm not sure but you might be able to support them without changing anything else.

Solid rotors on a car that large was not a good idea to begin with.

Steve

You can swap the vented front rotors in along with the corresponding pads with no other changes. The pads for the vented rotors are thinner to make up for the thicker rotor meaning they will wear out a little sooner.

Sent from my XT1097 using Tapatalk

LLL said:

"You need to read and comprehend my first post."
So do you!... my previous. I'm not in the mood
now to prove something obvious. I'm off - click!
oilhammer, I have drums rear.
No, Steve Addy, I have solid rotors.

Click to expand...

You must be one of those type of folks that keeps repeatedly posting stupid question until you get the answers you want.

What I was telling you is absolute gospel for modern Dubs. anyone that thinks you need to turn modern dub rotors is an imbecile or is living 30 to 50 years in the past when we did turn rotors and drums routinely.

Modern VW recommendations are to discard the rotors at every pad change. There is absolutely zero recommendations from VW to turn the new rotors at that time.

Your "rotor turner" is living in the past when turning disks and rotors was a common practice. turning rotors mounted on the car went away just so many years ago as well.

Seriously, you need to wake up.

I replaced my rear disks and pads about 70K miles ago, and all I did was put the new parts on, check for binding guide pins and go. No turning or theoretical troubleshooting issues. So far, my brakes are flawless.

IDK how many different ways I can tell you. You do not need to turn VW rotors because when the pads are done, the rotors are done and need to be replaced.

Ol'Rattler said:

Modern VW recommendations are to discard the rotors at every pad change.

Click to expand...

Seriously? Didn't know that. Costly!

Ol'Rattler said:

You must be one of those type of folks that keeps repeatedly posting stupid question until you get the answers you want.

What I was telling you is absolute gospel for modern Dubs. anyone that thinks you need to turn modern dub rotors is an imbecile or is living 30 to 50 years in the past when we did turn rotors and drums routinely.

Modern VW recommendations are to discard the rotors at every pad change. There is absolutely zero recommendations from VW to turn the new rotors at that time.

Your "rotor turner" is living in the past when turning disks and rotors was a common practice. turning rotors mounted on the car went away just so many years ago as well.

Seriously, you need to wake up.

I replaced my rear disks and pads about 70K miles ago, and all I did was put the new parts on, check for binding guide pins and go. No turning or theoretical troubleshooting issues. So far, my brakes are flawless.

IDK how many different ways I can tell you. You do not need to turn VW rotors because when the pads are done, the rotors are done and need to be replaced.

Click to expand...

How about we not say things that are hurtful when the person was seeking comments about his braking problem.

What may be common practice for you here in the US might not be that in other parts of the world.

It's this sort of thing drives people away, let's not do that, ok?

Steve

I'm so sad that there is no "block" option here .

LLL said:

I'm so sad that there is no "block" option here .

Click to expand...

Since when?

To activate it, click on their name, and under the heading that says 'User List', click on 'Ignore this user' and you won't see their posts and they won't see yours.

lisab4 said:

Seriously? Didn't know that. Costly!

Click to expand...

Not all that much more than turning them and then if you do turn your old VW rotors they will be under limits and need to be replaced anyway.

Some folks have had good luck with just replacing the pads if the rotors aren't seriously glazed or worn from metal to metal.

Steve Addy said:

How about we not say things that are hurtful when the person was seeking comments about his braking problem.

What may be common practice for you here in the US might not be that in other parts of the world.

It's this sort of thing drives people away, let's not do that, ok?

Steve

Click to expand...

Well, my apologies to the OP then. LLL I just sensed (right or wrong) a "deer in the headlights reaction from you and I should have been more tactful.

I'll work on that..............

I didn't know that, Abacus, thank you!

I formerly worked for Akebono, I've dealt with dozens and dozens of "warped rotors".

You need to indicate the hubs and make sure they're running true.

Then you need to measure your rotor not for runout, but for thickness variation across the surface (inside to outside face) if you see any more than 0.003" that's an obvious cause of brake judder.

Secondly which brake caliper grease did you use and how much? Did you replace the guide and lock pins? Did you clean the bores thoroughly until they were spotless so you could check for wear marks?

Usually a quick cleaning is enough but because this a continued issues this warrants more serious investigation.

Secondly I would use a bare minimum of grease, in a caliper that size 5 grams +/- 1 gram is plenty per pin. Remember the only thing retracting your pad is the O ring. If the piston is not retracting properly the pad will hang up and eventually (10k miles) wear a low spot on the rotor. You'll feel this as warpage or judder.

No such thing as warped rotors. Deposit on the rotors, sure.

My brake vibration problem is solved, please read one of my previous posts

I've had this problem from time to time. So don't feel bad. LLL The brake problem that is.