Rotors warped again, 4th time

[KHarrower]

My front brake rotors are warped again leading to the front end wobble when braking thru 45 mph. My rotors have been turned three times since April, about every 1500 miles. The rear brakes were inspected the second time, (brake cylinders rebuilt, brakes adjusted), new front brake lines the third time (suspected that brake lines were not allowing fluid to return, causing draging pads). I can only suspect 1) as DP commented last time, my rotors have been turned beyond minimum thickness and will warp easily, my brake shop says they alway mike them?? 2) the calipers are not releasing although brake shop says they are, 3) a combination of both. Right now I plan to replace rotors, calipers and install ceramic pads which are suppose to cool faster, although they do wear the rotors faster. Any other ideas from the experts. I dont' know what else to try at this point, and would rather be spending my $$ on new injectors instead of a 4th brake job. I feel that I am pretty easy on my brakes, and that they should last more than 1500-2000 miles. :{

 

[glhs]

I would also suspect thin rotors or cheap pads that get hot too easily.

I just changed my original pads at 124,000 and decided to spend the extra money on oem pads since I never had any problems. I also upgraded the rear brakes to 3 inch shoes and larger wheel cylinders. Is it possible your back brakes are not working/helping at all? The back brakes help more than what most people think. My 2 cents.

Kurt

Kurt

 

[DPelletier]

Yes, its possible your back brakes need to be set-up. Back brakes provide 30% of your stopping force, when properly adjusted. It is common for drum brake star-wheel adjusters to be frozen and not keeping the rear brakes adjusted properly. Manually adjust them if necessary or if the owner's manual "go fast in reverse and brake strongly" every week or so isn't working. I know you said the rears have been adjusted, but maybe they weren't working properly before.

As far as the rotors go, unless you are panic braking while towing, the rotors shouldn't warp. As I've said before, brake jobs are a bit of a scam in that the shop will always turn the rotors every time they install new pads. Every time the rotors are turned they get thinner and more prone to warping. So, they turn them, they warp more easily, they turn them again, they warp even more easily and so on until the rotors are thinner than the manufacturer's minimum thickness and you have to buy new rotors. Yes, they'll tell you that they mic them and there still within spec, but think about it for a minute; they're warped right? That means when they turn them they are no longer uniform in thickness. When it isn't uniform thickness anymore, it heats up and warps much more easily than before.

I have a small fleet of trucks now and no longer have the time, but when I was younger, I simply would put new rotors on and just keep and eye on the pads and replace them myself when necessary. Sure, it would take a little while for the new pads to wear in to the grooves in the rotor, but my rotors seldom warped. It's a heck of alot cheaper to replace pads every so often than it is to pay for pads, calipers, rotor machining etc. etc. Brake pads were maybe $75. 00 compared to the full blown brake job at several hundred dollars.

If I were you I'd forget turning the rotors and buy new ones (if OEM rotors aren't too much $, they'd be a safe bet) and then follow the above procedure. Make sure your driving habits aren't contributing to the problem. Never ride the brake. Brake when you need to and then let off to let them cool down, especially towing loads downhill.

Some vehicles just had rotors that were too small or too thin and they warped easily. Ford F-150's and Explorers are among the worst offenders. Most 3/4ton trucks have big enough rotors to hold up.



Sorry for the long post,

Hope this helps,



Dave

 

[BushWakr - RIP]

The latest TDR mag has a great article on brakes/proportining valves/brake system operation... give it a read thru. It's a tad technical but it's worth the read.

I also remember reading somewere that DC started turning rotors while still mounted on the truck. This was a solution to making sure that the rotor was turned "true" while mounted in/on it's operating surface... maybe do some digging on that one...



pastor bob... .

 

[Hohn]

I'd suggest new rotors and cryogenic treatment. I've NEVER heard of a cryogenic rotor warping...

 

[JLEONARD]

Yes, they'll tell you that they mic them and there still within spec, but think about it for a minute; they're warped right? That means when they turn them they are no longer uniform in thickness

FWIW

I'm not ready to agree with that. My son's brake lathe cuts BOTH sides at once to maintain uniform thickness... that's the point.

He also takes a skim cut on ALL new rotors prior to installation... . he's been burned too many times by OEM replacements that are supposedly to spec but give a bad pedal feel.

Jay

 

[1stgen4evr]

front end wobble when braking thru 45 mph.

There is more to that problem than rotors. All the comments are good in my opinion but you may have something else that is contributing to the wobble. Trucks would do the wobble dance long before brakes were rotor/caliper systems. Tires, tire wear, alignment, steering damper, steering joints at the various points, shocks and probably some thing I don't know about can and will at times start the wobble.



To say the least, you repair man is not addressing the problem by turning the rotors and installing new pads FOUR TIMES. What about your steering shaft pot joint? Do you have a Borgsen shaft? The steering box is mounted on a plate on the fwds. Any problem there? Cracks, loose? Once the slightest begining of a wobble starts, it will amplify till you slow down. Check the posts on death wobble on the fwds.



After four times shaving the rotors, you probably DO need new rotors, but look deeper into what is really wrong. I had a sticking caliper on a New Yorker that caused a serious problem. The rotors would heat to the point they glowed. These calipers were rebuilts from a major supplier. If they won't return/release after applying the brake, you will get enought heat in the rotors to warp them.



When you find the real problem, post for our enlightnment. This is how we learn to keep these old trucks on the road. And good luck. Some times these things can be a son of a gun to solve.



1stgen4evr

James

 

[Bob Beauchaine]

While my problems were not as severe as yours - warping every 20 to 25 thousand miles - it was still not acceptable to me. I have not had a problem since I installed my exhaust brake. I use the exhaust brake all the time and have gone over 50,000 with no warp. It does sound as if you've got another problem going.



Bob

 

[Nordby]

I've been through brake hell on my D250, my wife's tow rig 2000 4x4 Powersmoke ( and two horse trailers!) In the last 2 months.



The f*rd rotors we turned twice, and they would blow within 2000 miles or so. It's like they had a memory in the warped position or something. Finally, we went motorcraft, brand new, lifetime rotors. We'll see. When towing the 9k lbs of horses and trailer, the truck and trailer would set to buckin like no one's business, at all brake controller levels. It'd resonate so hard the ABS would fire then the truck would quit stopping! I even pulled the ABS fuse, swapped controllers, etc. Finally I figured it was the truck when I unplugged the trailer completely and got it to happen with no controller/trailer brake, etc. You could barely feel the problem empty and unloaded, the load magnified the problem, as did speed.



My first gen 2wd would go into a tremendous wobble with the warped rotors. Even with recent king pins, tires balanced, bearings adjusted, shocks replaced. It would build on itself, a resonation kind of thing. Fixed with new rotors, even though they were in spec to turn. 4K miles and counting. I went with non metallic pads, in hopes of wearing cheap pads out and not expensive rotors.



Just some ideas.



jon

 

[DPelletier]

JLeonard,

Sorry, I didn't explain that very well. The rotors are hollow ventilated rotors. When they warp there is a "bow" in the disk. When you turn them, you do indeed turn both sides and therefore the outside to outside dimension is constant. HOWEVER the thickness of each side of the rotor now varies. It has to or it wouldn't have been warped.

Also, to clarify, shops (like your son's) have to turn the rotors for liability reasons. They need to ensure that the customer has 100% brakes the minute that they leave the shop. If rotors are warped, turning or replacement are the only two options. When you put new pads on old rotors, the rotors have grooves in them and the pads need to seat before you get 100% braking. Your son's customers expect (rightly so) that everything is done and working perfectly. He can't risk someone coming back with a leaking caliper or wheel cylinder and that is why almost all brake shops insist on rebuilding or replacing the calipers. Yet I've installed new pads dozens of times without getting a leaking caliper. Shops can't take the risk. The bottom line with brake jobs IMO is that you can often "get away" with only replacing pads at a fraction of the cost of a total brake job and your rotors will last longer if they're not turned every time the pads are replaced. If they're warped, of course, they will require turning or replacement. Past experience has convinced me that the more times the rotor has been turned, the quicker it will warp again.



Dave

 

[DPelletier]

Oh yeah,

I wanted to mention that earlier, As Jon has pointed out if you can find non-metallic pads, they will help the longevity of the rotors. The downside is slightly reduced braking power. Some of the more aggressive pads will really chew through the rotors.



Dave

 

[19Kgvw]

Sounds like you've got all the correct technical comments that you need. :-{}

Just one question: how much do you travel the teton pass with 10% grade and 8400 feet :--)



I was just in Jackson 2 weeks ago on my motorcycle and that's quit a pass. Fun on a motorcycle but he** with a 19,000 lb load.

 

[MrWinkey]

As said before also check the master cyl. I had a valve go out in a previous rig and it would drag the brake pedal at odd times.



Didnt notice it until one time it did it when I stopped. saw everything glowing and realized what the problem was.

 

[KHarrower]

19Kgvw, I will only travel down the pass on the Idaho side with an empty trailer (2400 lbs), 3rd gear, 35 mph, braking as little as possible. I take my truck to the shop tomorrow. We will put a dial on the rotors before taking them off to see how warped they are. My back brakes have been adjusted twice, so I don't think they are the problem. I will install new rotors at a minimum, most likely put on new calipers as well. And new tires. I am tired of the "death wobble", especially descending the Pass. I travel the pass at most a couple of times a month, and very rarely with a trailer. I also have recently installed a new steering box and borgeson shaft. Thanks for all the comments and suggestions.

 

[Wayno]

Well I learn a long time ago that you need to buy rotors that are made in the USA , Canada or Mexico if you want to stop the warping . Those overseas rotors are junk . I got a set from Raybestes that are made in the USA . They lasted a long time before the warped and they shake very little but the again the W. O. T stops I do sometimes doesnt help matters either . I even let my passenger side inside pad get down to the metal and I didnt want to take off the rotor because it is useless to have one turn because the rotors not that thick anyway so I took a small body air grinder and ground down the ruffness and put a new pad on it and it still shakes very little .

 

[KHarrower]

The rotors were miced and were warped again. They are also not at minimum thickness, although I did not witness the measurement. The technician experiened the "death wobble", which does not quit until slowing to 35 mph or less, and thought that something else must be wrong with the front end, but could not find anything. Everything is tight, and I just installed a new steering box and Borgeson steering shaft. I am replacing the tires, calipers, brake pads and rotors tomorrow. Would a steering stabilizer help?? I will do a search on the death wobble, but does anyone know of anything else to check for, or does this sound like the typical wobble which is being induced by the warped rotors?? Thanks again for the comments.

 

[19Kgvw]

A steering stabilizer will only be a bandaid for (mask) the real problem. You still have a root cause for the wobble and warped rotors with normal (not extremely warped) warping will only be noticed when apply the brakes or if really warped, it will be felt when ever the truck is rolling... with the wobble being more noticeable as speed increases. Your mechanic is missing something... king pins, steering knuckles, etc ???? my . 02

 

[Philip]

does this sound like the typical wobble which is being induced by the warped rotors??

No it doesn't. Its time to start looking deeper. The upper ball joints have plastic inserts that ride on a tapered king pin. The plastic inserts are held down with springs. The lowers are a bearing with a stud going threw them. If the bottoms bearings are bad. The would allow the uppers to jump up off the king pins and cause a wobble. The springs like to compress with age also on the uppers. Mine had compressed over 3/8" when I replaced them 2 years ago. We did Case500D's truck last summer. His were compressed 1/4". This was comparing new springs to the old ones. Shorter means less pressure at installed hight.



Is the steering box mounting plate cracked on your W model? Check the mounting bolt holes threw the frame for cracking also. Also check the rivits on the lower raditor support. These also are the front spring hangers. They are noted for coming loose with age.



Check the spring eye bushings close for seperation. This is the rubber to the metal sleve that the bolt goes threw.



On the outside. Check your rear axle for being bent. It can cause the same death wobble you are having also. Here is a link with a pic of what my axle looked like. I chased a death wobble and what seemed like warped rotors for a while.



https://www.turbodieselregister.com/forums/showthread.php?t=56738

 

[Jacek]

You might also check the front rims and tires.

I had a vibration that was finally tracked down to a busted front tire belt.

Just another thought.



Jacek

 

[KHarrower]

Well, I replaced the rotors, calipers, pads and tires yesterday but am still suspecting other possible problems. While checking out the rear ABS, I found that someone (dealer??) had removed the light bulbs from the anti-lock and parking brake annunciator lights, so I had no indication of possible problems, or no way of checking the codes. I will replace the bulbs and see what happens. We, (the brake shop and I) are pretty sure the rear brakes should work normally without the ABS working, but want to check out the system anyway. Lets see, how many months worth of payments could I have made towards a new 600 by now. I also did the skid test to see if the rear brakes are working, (on gravel). Left rear skidded but not the right. I then felt both front rotors. Hot, but I could keep my hand on them, same for the left rear drum, but the right rear drum was only luke warm. Another problem discovered.