karlr

Hi there,

I've joined this forum to attempt to find a problem to an ongoing problem I have with my truck. I have a '98 G1500 full size van (sorry, I'm posting to the Tahoe section, but it seems like a popular group, and these vehicles have a lot in common).

I have 215K miles. Original brakes lasted over 125K miles (lots of highway), were replaced, and lasted another 50K, and since then, have needed replacement ever 5-10K miles. It's getting ridiculous.

I have been diligent about putting on new wheel bearings with new rotors, and have tried everything from cheapy AutoZone rotors to really expensive high quality rotors made here in the U.S, as well as Canada. I've tried doing a final grind before installing, per other recommendations, to guarantee that the rotors are truly flat before install. Nothing works. They keep warping, at the same rate they always do.

My technique for installing rotors used to be tighten the bearing nut on the end of the spindle with a wrench, to a few foot lbs (maybe 10), then back it off, and tighten it as much as I can with my fingers until I can slide the pin through. I've been told to be more aggressive with overtightening initially, to guarantee that the bearings seat properly. That has not made any significant difference. I've also tried adding a little bit of extra preload to the bearings before pinning, with no luck.

I've been careful with torque on the lug nuts (i.e not overtightening the nuts). Nothing seems to make any difference.

I use high quality Napa brake pads, and have tried the crappy $20 Autozone pads in the past.

I've had similar experiences with past vans. Other mechanics hear my story and are not surprised. I feel like nobody knows what is going on.

I am wondering if the wheels bearing spindle could be affecting this. The spindle is definitely worn, probably from the bearings wobbling around during the worst vibrations. I have a hard time believing I'm the only one that has this problem, and find little evidence of this being a common replacement on trucks (spindles seem to be mostly sold as a complete disc brake kit for custom work). Has anyone been able to correlate this to warping rotors? I see no evidence of blown balljoints or steering joints, and the shocks are performing fine (I've heard lots of people blame warped rotors on front end problems, and I'm skeptical).

I'd appreciate any input.

Thank you,

Karl

stickershock

I have had to replace the front wheel bearings on two cars recently, one a Corolla and the other an Impala... neither one had made it to 100K miles yet either! Your spindles might be galled from previous bearing damage I should think. I would also think that if you are not using a torque wrench to tighten to specifications.... well maybe that is a problem as well. I would think also that the runout of the rotors would tell you if they are in specification. A tech would put a dial gauge on them and spin them. There should only be so much plus and minus from zero readings (ie, the runout). Sounds like this is old news to you, but just trying to throw out some ideas.

loulblades

An issue that can add to this in our older vehicles is the caliper not sliding freely enough to allow the outside pad to disengage completely from the rotor, causing the rotor to heat.

Search this forum for some info on the proper lube to use to aid in allowing the caliper to float more freely on the pins.

I currently upgraded to SSBC calipers and rotors and we will see how that goes.

EvansBlue

I'll move this to the Express section after a while. We have good techs that go all over the forum, so no need to post in the wrong section to get an answer.

Expresses and G vans have big problems with wearing out pads prematurely. You may want to try ceramic pads next time to see if you can cut down on the heat buildup.

stickershock

Thats a good point about calipers needing to slide or glide to function properly. If your pad wear is even then there is no issue, but I had uneven pad wear and the problem was rusty caliper pins that wouldn't allow the caliper to function properly. Root causes are really nasty to determine, aren't they. By the way, my ATV manual calls for silicone grease, if that can extend to car brakes, but ATVs are in the water more than a car, so maybe cars use something else. A call todealer service would advise you.

Then again, maybe a simple call to thedealer service dept. might tip you off to a solution, since they may see the issue frequently and know the fix. Some dealer service people are good about kicking around ideas on the phone, some aren't, so try a few if you haven't already. Also, Euro's idea is good as well about the posts.

karlr

Thanks for all the input so far!

I don't have the info on the NAPA pads that I am using. I expect they are ceramic, but I might be wrong. They have a lifetime warranty (meaningless, really), and NAPA will give you replacement pads for the life of the pads. They came with all new lube and seals for the calipers, and prior to using these pads - these are the nicest set of pads I've ever seen for a van, and at $85, the most expensive.

I do make a point of re-lubing, and using a brillo pad on the glide pins if there ever were to be any rust on them. There is none on these, and they're nicely lubed. That does bring up a question though - it seems that an extraordinarily small amount of lube should be used. These pins have a fairly high tolerance, and if you put on a dab of grease, they tend to not pull in and out easily, since the lube fills the gap and creates a pocket of stuck air at the end of the pin, in the blind hole into which they insert. I wonder...

The spindle is not really galled - it's just worn, kind of like a cam lobe with high mileage. It's not worn uniformly though, so I worry about high tightly that inner bearing race sits on there, and the fact that it is clearly rotating on the spindle (or a set of bearings did at some point, probably due to inadequate bearing preload), which I expect it is NOT supposed to do. I just hate to spend a small fortune replacing them if there's no indication that this is the source of my problems. I'll see if I can take some pictures - I think that may help y'all determine if this is at all significant.

Thanks!!

Karl

e

Have you applied slide lube to the surface of the spindle where the caliper rides? You should be able to move the caliper freely side to side after the install with little force. If the caliper isn't moving freely than the heat build up and uneven pad wear will happen.

in2pro

A couple of things to check ( I had a 1997 Tahoe that went thru rotors also) service your rear brakes they help keep some of the load off the front ( 70% front 30% rear typical loading)
check your front calipers as they may be clamping down on the rotors differently and casuing excessive heat, don't forget to check the brake lines also the can sludge up after many years of not being bled.
given that the truck is 10 years old I'd consider replacing the front calipers and brake hoses along with servicing the rear shoes and brake assembliesand checking out the proportioning valve.

cheyenne

HAVING SAME PROBLEM WITH MY 2008 CHEVY EXPRESS VAN
MY PROBLEM ----COPY & PASTED FROM ANOTHER THREAD----

I bought it certified with 14,000 miles. It came with a 36,000 warrenty. I now have 94,000 miles on the vehicle and I am on my fourth set of rotors!! And on top of that I have the original brake pads. As a matter of fact from 14,000 mi to 94,000 my brake pads have not worn at all. Chevy gives you a print out of how much remaining brake pad is left and my brakes have not worn AT ALL in 60,000 miles. Every old school mechanic I talk to says this is a RED FLAG that my brakes are not operating properly. I had to cut the rotors at 30,000, and then at 50,000 they were warped and too thin to resurface. I Replaced them again. At 80,000 I had to have them cut because they were warped. Then at 85,000 I had to have them replaced again because they were warped. I live in Illinois but use the vehicle for a business that has me traveling from state to state. Everytime I take it in the rolling hills of Missouri, of god forbid the mountains of Colorado, after 1 hour of hills or mountains, I can feel that they are warped. Within 1 hour of mountain driving my rotors get to hot that when I brake, my whole steering column shakes and the vehicle swerves to hard that I can barely stay within the lines on the interstate. I seriously feared for my life the four times that this has happened. I have tried to have Chevy look into this and everytime they just slap new rotors on and send me on my way. I keep telling them there is something else wrong. They give a 12,000 mile warrenty on rotors and they are warping in half that time. Chevy has had to replace them for free under warrenty 3 times and I have had to pay once. I feel like all they want to do is slap new parts on instead of finding the problem or having a
RECALL! As a matter of fact my dealer told me that they have a couple other customers that use their Chevy 3500 Express Van as a work truck and that the same thing keeps happening to them. They try to tell me it must be my driving/braking in mountains. First of all I grew up in Colorado and had a 1984 Dodge Ram Van and never put rotors on in less that 100,000. I know how to drive in the mountains. I have spoke to corporate, who agrees something else is wrong but they won't do anything about it. They say they've checked everything. But they won't check the pressure in the master cylander with a gauge. I finally got the service supervisor to admit to me that these vehicles have crappy metal rotors from China and that they have been failing in the saftey lane tests for their ability to brake and stop in the required distance. I bought the 3500 1 ton van because I believed it would last me for years as a work vehicle. I feel that my vehicle was overated to it's weight limit and it cannot stop itself if it has ANY kind of load in the cargo area. It's just really scary because I use it for work and I have to travel to these areas and I fear for my life everytime I drive in the mountains. I am going to be writing to all kinds of people at Chevy as well as the better business bureau. I have already filed a complaint with the US DEPARTMENT OF TRANSPORTAION HIGHWAY SAFETY ADMINISTATION. THERE NUMBER IS 1-888-37-4236. IF CHEVY RECEIVES 3O OR MORE COMPLAINTS A RECALL INVESTIGATION WILL BE LAUNCHED. I am also going to contact a local Chicago newspaper writer who takes on stories like this when people are wronged by corporations. This isn't really about being wronged as much as it is about being safe.

73shark

Something that can cause warped rotors besides overheating is over-tightening/uneven tightening of the lug nuts.

Also the inner wall of the brake hose can deteriorate and can cause the pressure not to release when the pedal is released thereby keeping the pressure on the pads.