Front brake rotors warped on 99XJ

Is it just me or are the front rotors undesized on these XJs?

I have a 99XJ, 4WD, with 225/75R15 tires.

About 2 years ago my old rotors warped.
At that time I bought new Raybestos rotors and ceramic pads.

The pulsating has started again.

It seems to me the front rotors were under sized for this vehicle.

Should I get used to buying a new set of rotors($80-$100) every time I replace the pads?? This sucks.

MAP

You might want to make sure that the lug nuts are being put back on properly. If they are just using an impact they may be way overtightened. They should use a torque stick or torque wrench. An impact wrench warped the rotors on my moms car a few years ago.

Where the hell are you buying rotors that it's $80-100 for a set? Mine were $16 each at Autozone.

RyleyF said:

Where the hell are you buying rotors that it's $80-100 for a set? Mine were $16 each at Autozone.

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...maybe he is buying halfway decent ones, instead of that CCC (cheap Chinese crap) that are guaranteed to warp by next week or your money gladly refunded in Yen.

At the time I bought them, only Raybestos made that particular part number. In 97 or 99 they switched the height of the rotor and I had a hard time even finding the things..
At the time I bought them they were $35 a piece. If you look up the price of rotors at Autozone, they have Bendix rotors for $100+ each!!


$16 bucks... I can't even find pads that cheap.
What year XJ do you have? Those must be those older cheap ones with the sheet metal hat...

I only use a torque wrench for tightening the wheels.(100ft.lbs, manual says 85-115ft.lbs.)

MAP

MAP said:

Should I get used to buying a new set of rotors($80-$100) every time I replace the pads?? This sucks.

MAP

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many people here swear by the cheap rotors/expensive pads. I replaced my rotors 3 times in 2 years. It got so annoying I tried cheapos from Pep Boys. they have been great now going on 2 years. I also lowered the torque down to 90. Mine is a '00. I may wear out the pads first for a change.

I say you got nothing to lose trying the CCC's. I paid around $25 each.

I'm familiar with brake work, but not specifically the XJ rotors. Anyone tried the drilled/slotted variety, and if so, at what cost/where? A friend found some for his ZJ $80 for the pair. My '99 has started to pulsate and veer slightly on very hard braking, NoVA style hard.

(For you West-Coast guys, NoVA hard braking is like SoCal braking when an SUV just in front and two lanes over sees a mall and instictively swerves at 70mph).

Even with just 31" tires, the first time I did some fast mountian trails I warped my stock cast rotors pretty bad.

There are a couple different people selling crossdrilled rotors for the cherokee on ebay, and of course many places sell powerslot too. Personally, I don't like slotting, so I just ordered a set of the crossdrilled only and we'll see how that goes... total including shipping was about $100. If these warp then Autozone can special order some Baer crossdrilled/slotted rotors for 180, and I might try those next if these no-name turn out to be crap.

Let us know how that goes.

I like Ebay, but I won't buy brakes or suspension stuff there. Feedback doesn't mean sh!t if I step on it and don't stop. I've got precious cargo.

I got my last set of rotors from carquest, $20 ea or so, pads were $30 [blueline] and so far so good. They do dust a lot though. Oh, they are also NOT composite rotors and I torque them to 90ft/lbs, carry a $25 long 1/2 torque wrench, extension and socket under my back seat just for wheels and such...

I guess I'll give a cheap set of rotors a try.
I believe Autozone has some for $20..

Thanks,
MAP

MAP said:

Is it just me or are the front rotors undesized on these XJs?

I have a 99XJ, 4WD, with 225/75R15 tires.

About 2 years ago my old rotors warped.
At that time I bought new Raybestos rotors and ceramic pads.

The pulsating has started again.

It seems to me the front rotors were under sized for this vehicle.

Should I get used to buying a new set of rotors($80-$100) every time I replace the pads?? This sucks.

MAP

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Stay away from the ceramic pads they will cause havic on the rotors. go with non ceramic. jeep pads and a good set of aftermarket rotors. and torque the wheels. How about the calipers, they good. How about the caliper slides on the knuckle, are they smooth or are they marked up?

Pete

No luck finding inexpensive rotors. I show 2 different rotors for a 1999 XJ in all my searches. One is 3 1/16" overall height and the other is 3 3/16".

For the 3 3/16" rotor the lowest priced rotor was $20.

Unfortunately the lowest priced rotor for the 3 1/16" rotor is $30.(at Autozone)

I found $21 rotors at rockauto.com but ground shipping is $25 which defeats the purpose of buying cheap rotors.

I just realized that I've had the same rotors and set of ceramic pads on my XJ for 60,000 miles. Considering how long they lasted, I guess it wasn't a bad deal.

The ceramic pads are on the thin side now.

Since I'm going to replace both disks and pads, I think I'm just going to let them wear until the warping gets annoying.

I'll probably put in the $40 rotors from Autozone. The cheap rotor they had is only $10 less. I might go with ceramic pads again.

Can someone explain why the ceramic pads are bad?
All I've read are good things about them?
My current set have certainly lasted a long time.

Thanks,
MAP

Ceramic pads are fine if used on rotors made for them. With stock cast rotors you can figure on replaceing the rotors and the pads. The ceramic pads are as hard as the rotor so the both get wore out at the same time.
As a guide, with non-ceramic pads you change the pads every 30k miles and the rotors will last three pad changes. With ceramic pads you will need new pads and rotors every 60k miles.

I had my rotors slotted at the local machine shop for $25 no big deal makes a big differnce in long hard stopping situations like towing and steep hills. Ive never had good luck with crossdrilled rotors not either cracking between holes or warping so I paid $45 each for a set of cast rotors from a reputable company and had them slotted in 5 places each side. almost 40,000 miles and im stil on the same set of ceramic pads and rotors. As it was previously stated ceramic pads on rotors not designed for them will chew them up very quickly. BUT putting crappy pads on a crappy rotor will have the same effect

Not to be argumentative... we'll maybe I am.

The ceramic pads are hard but there's no way they are harder than the rotor. The ceramic pad wear has been considarable over 60,000 miles.(but long lasting considering..) The rotor wear has been very slight. The ceramic pad manufacturer's don't specify that they are to be only used with certain rotors.

In my opinion, the reason these rotors warp is because they get too hot and do not dissipate heat as well as they should.
The only solution would be for the rotor braking surface area to have been bigger/wider. I still believe these things were underdesigned and the fact that so many people here have had problems supports this.
If the problem is the surface area being too small, no matter what disks I use, they will end up eventually warping.. unless I use some pricy cross drilled/high performance rotors that are designed to dissipate heat better.

Of course a cheap set of rotors will probably warp more quickly no matter what set of pads I use. So, it all depends on how often I want to change the brakes rotors. langer1's guidelines are a direct reflection of my situation.

The issue is the only way to have consistent/predictable results is to use the same set of rotors I had.(Raybestos) Unfortunately these rotors are $20(each) more expensive than when I last bought a set 2 years ago.

So here's what I'm going to do. Run what I have until the pulsations annoy me then replace with a set of Autozone rotors that have 2 year warranty for $40 bucks each. Then I just need to decide whether to use ceramic pads or carbon/metallica pads.
Any one have any suggestions on one over the other?

Thanks for all the feedback.

MAP

kevin s said:

...maybe he is buying halfway decent ones, instead of that CCC (cheap Chinese crap) that are guaranteed to warp by next week or your money gladly refunded in Yen.

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Chinese currency is Yuan, or RMB.
I actually returned from China on 8/28. The factory making parts for my company also makes brake drums and they actually look decent.
I also saw another company in Dalian that machined (not cast) rotors. Their machines were all computer controlled and less than 10 years old.
But I concede that one common problem is the quality of the material going into the parts (aka: garbage in = garbage out).

kevin s said:

...maybe he is buying halfway decent ones, instead of that CCC (cheap Chinese crap) that are guaranteed to warp by next week or your money gladly refunded in Yen.

Click to expand...

I am owned by my own post!

I have purchased CCC in the past. I frequent Harbor Freight, too. My original response was more a reaction to the seemingly common opinion around here that you have to get the cheapest price on everything, or you are a dunce. I try to buy "important" parts at NAPA or the dealer, but even NAPA has its lower line of products from our friends in the east.

As far as rotors go, the way the NAPA guy explained it, you can get the good ones and turn them next time around, or go with the cheap ones and replace them next time around. It's a lot less hassle to put on all new parts, rather than find a place to turn them, and maybe have to leave them and come back. Time is money. By the time it's all said and done, the CCC is usually adequate, at least for street machines and stock tires. That's my take.

I must be very lucky. I've had the same rotors on my 89 axle for the last 50K with no problems and never turned. I'm on my second set of Bendix SUV pads.

Just thought I'd add some info and thoughts on this topic.

This past weekend I replaced my pads and rotors. Now the braking is nice and smooth, so the rotors were definitely warped.

Now here are my thoughts on this. I replaced the rotors with a set from Autozone and a set of carbon metallic brake pads.

Right away what I noticed was that the braking was smooth but I also noticed that the brakes didn't have the nice grab that the ceramic pads had.

I have to press harder on the brake pedal to get these brakes to grab.
(I did not open any brake lines so there is no reason to suspect air in my lines)
But although I get better braking with the ceramic pads, I think this may be the reason that my rotors may be warping.

I've used ceramic pads exclusively on my XJ since I've had it over the last 5 years/100,000 miles. My last set of rotors also warped.(prior to the ones I just replaced)

Prior to my XJ I had the 1st year model of Chevy's first front wheel drive econo sedan. I'm not going to mention models...
But anyway, I used ceramic pads on that thing and had the same problem. My rotors warped.

My thinking is that since the ceramic pads are better insulators of heat, they do not allow for heat to be dissipated from the rotor when braking and this may be what is causing the rotors to warp.

Only time will tell. If my theory is correct, my new rotors should not warp, if I avoid the ceramic pads.

MAP