Are all rotors created equal?

ScottWisdom

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My suburban is murder on front brake rotors and brake pads. I go through brake pads every 5000 miles. I've replaced the rotors and they warp almost immediately and it's time to get new ones again.

Are GM rotors any better than the cheapies from Pep Boys or Kragen? Is there a better rotor that won't warp as quickly? I've already tried the slotted/vented type.

By the way, it's a 1995 Chevy Suburban, 3/4 ton, 4 wheel drive with the 454.
 

John Bitting

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Scott do you have the discs in the back? On my older chevy I went through brakes up front quick but it was because the back brakes were no bueno. On my new 02 chevy they say with 4wheel discs you can go like 50k before you need front brakes. We shall see.
 

motoxscott

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Like John said, maybe you should look at converting to discs in the rear. My superduty has about 30K miles on the original pads and I have been pretty hard on them, plus the truck weights a ton.

Also maybe the proportioning valve is off, it might not be sending enough pressure to the rear, so your front brakes are doing all the work.
 

pciscott

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Scott I thought you Pro1600 guys didn't run discs? Why don't you put on a good set of drums? :) Just Kidding.

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jeff

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My 2000 Dakota would warp a front rotor in about 2500 miles. That happened 3 times within the first 8000 miles and the dealer wouldn't fix it anymore because they said it was my driving style. I drive my Dakota MUCH easier than I drove my S-10 and that thing would go 80-90000 miles on pads and not once did I warp a rotor so bad it was noticable in the pedal or steering wheel. I've come to find out that THOUSANDS of Dakota owners around the world have been complaining about premature rotor warpage - you might want to find out if other GM owners have had the same problem as yourself.

I removed the stock Dakota rotors and replaced them with some inexpensive Powerslot rotors using the stock pads. I've driven 65,000 miles since the install and haven't even felt a hint of rotor warpage. The stock pads are about 1/2 left and I'll replace them before I sell the truck (hopefully soon). This includes probably 100 trips up and down the mountain between San Berdoo and Lake Arrowhead, a couple trips where my mom towed some stuff to San Francisco and back, and a whole bunch of Orange County haul ass stop fast freeway driving. I'd never go back to stock OEM stuff after my bad experiences. If the GM rotors are as piss poor as my Diamler-Chrysler rotors were, aftermarket might be your only hope.

Aloha
 

ScottWisdom

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Yup, my Suburban has drums in the rear but they don't do much. I love my Suburban, but Suburbans have notoriously bad brakes. The front discs handle about 90% of the braking. I agree that something's wrong...my guess was the proportioning valve. I've been to the dealer and they can't help. Their solution is to try and sell me the new model with discs on all fours.

At this point, I'm just trying to find good rotors that are more resistant to warping. The Chevy dealer is telling me that the rotors are warping because I didn't use genuine GM rotors when I replaced them the last time. "GM rotors are better than that crap that the parts stores sell."

Sounds like a bunch of B.S. Just thought I'd get a reality check from the experts on RDC!
 

Eric_M

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im curiouse, have ou ever turned your rotors after you noticed they were warped? if not, i would try and turn them and most of the time (depending on how badly the rotors were warped) will be able to be used again. sometimes you can even turn them 2-3 times befor replacing them. just my .02

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evan_clanin

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if u tighten the lugs down to much u can warp a rotor but i would take alot or a extream change in tightness from one to another, but it does happen, usually guys playing in there driveways on the weekends, thinking there on a nascar pit team doing it as fast as they can over and over again, to there wifes new car!!

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ScottWisdom

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I've had the rotors turned after they warped, within a week they are warped again. Don't think I have too much torque on the nuts. I'm not using an air gun. Just using a 1/2" ratchet to snug 'em up.
 

ScottWisdom

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John - Where can I get that done? I've read a few do-it-yourself articles, but I've seen feedback forums with negative results. The kits are using the brake setup off a cadillac or something. Complaints about losing the parking brake. Also complaints that the kits are missing essential parts that the owner must go find themselves. The kits advertise as "direct bolt-on" but all the feedback I've seen said that lots of modifications are required to make it work. After all was finished, most said they spent between $1200-$1500 for a do-it-yourself upgrade for rear discs.
 

John Bitting

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Ouch, that seems rather expensive. I myself have never done it. But I am sure people on here have. I thought the kits were only like $400. Maybe Stillen or someplace like that would know. I know I have seen advertisements in the back of Magazines.
 

Kritter

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Try having them turned on the vehicle as opposed off. I ahve heard that may help. I think somebody from this forum mentioned it...where is our Wilwood brake engineer at?

Kris
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V8Ranger

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Also make sure you tighten them in a criss-cross pattern and gradually work your way up to the proper torque specs (don't tighten one to 80 ft-lbs before snugging up the others).
 

ntsqd

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Right here. Some of us have to work during the day :(

Do you sit at a stoplight with your foot on the brake pedal ? Could be that the rotor mass is marginal (see below) and the uneven cooling caused by the pad being in contact with only part of the outer surface is warping the rotors.

Uneven torque can warp the rotors once they've been heat cycled a few times. Use a torque wrench as the final step in tightening the lugs.

First thing I'd do is get some pressure readings. We sell a gauge that replaces one of our bleed nipples. Those are conveniently 1/4-20 threads so making an adapter to what ever your calipers or wheel cyls have for bleed nipple threads should be a simple lathe operation. I'm guessing the same as others above me have, not enough rear brake pressure. I disconnected the Load Sensing Proportioning Valve on the rear of my Toyota from the axle housing and wired the arm to the cross member. Mucho better stopping. If you have any sort of ride height sensitive proportioning valve make sure it is correctly adjusted first. Then try imitating more rear weight with the adjustment until it stops the way you think it should.

Sounds to me like the rotors may not have enough thermal mass. Seems to be a common thing in late models, the OE's keep trimming weight out trying for the ever increasing CAFE stds and the brakes suffer. Look for the rotor that weighs the most as a starting place in chosing a rotor.

I'm pretty sure we don't have a P-Brake kit for a 6 or 8 lug truck. Later model 14 bolt's came with rear discs. They are a drum p-brake located inside the disc's hat. Far better design than the Cadillac Hydro-Mech caliper design. Might try looking for one of those axles complete.
The Cadillac option suffers from a poor p-brake design. In concept it may be fine, but in application what you end up with is a very sensitive balance to maintain. If the p-brake adjustment isn't spot-on then the rear braking suffers, sometimes rather dramatically. Most of the kits position the caliper somewhat poorly, bleeding usually involves pulling the pin/bolts and repositioning the caliper so that the bleeder is straight up.

Lastly, try some Raybestos "Brute Stop" pads. See if those help any. Could be your pads are having to generate too much heat to get into their heat range in order to stop the truck. Unlikely, but possible. The Brute Stops are agressive enough that you may not need the brakes for as long or as often. Downside is that they do wear a little faster than most.

TS

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fox_mccloud2000

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I know your problem. I used to drive an '87 Ford Van. It ate through the breaks and rotors like a baby eating candy! But the proporshing valve was bad for that year. I wish I still had that van.
I also have the same problem on my '87 4Runner. The origional rotors from 222k ago. Imaginge that. Like before, those rotors warp easily! If I could find someone or company to cross drill them, to despiate heat. Sad thing is I can't find any companies that make custom rotors for my car! BLAH!

anyways thats my 2 cents.

-matt-
 

Billy_the_Kid

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The "el cheapo" rotors from stores like Pep Boys are most likely imports from China and truely are junk from the word go. In recent years they have flooded the aftermarket with junk drums and rotors. I would start by buying quality GM American made replacement parts. I would also check whether or not 3/4 or 1 ton parts would fit and be heavier to reduce the warping.

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FABRICATOR

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John probably made the best diagnosis. Your back brakes may be weak. All you have to do is test it in the dirt. The fronts should lock up just slightly before the rears or at the same time. If they lock up way before, then you need to see why they are out of balance. It could be as simple as the wrong lining or adjusters that are not working in the rear. Unlike cars, 3/4 to 1 ton trucks (and all Suburbans) have brake power about balanced between front and rear. Above this weight rating the rears become a higher and higher percentage of overall braking. A few years back, many truck tractors had no front brakes at all!

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