1991 f150 4x4. I bought this beautiful truck with a warped rotor, like badly warped. How big of a job is it? Is it better to just buy the whole hub assembly? Any one have and good links to show how to do it? I am just getting tired of feeling like my fillings are going to shake out of my teeth everytime I brake lol.


Thanks

 

If it's warped that bad you may have to buy new. Otherwise you can have them turned. You do need to take apart the wheel bearings and if you end up needing new rotors it would be a good time to change bearings as well. I don't have any links but if you haven't ever done them it would be good to get a good manual or have someone help you that has done them.

Doing it wrong could ruin your day....

 

why did it warp?

you need to find out and fix that problem.

also, per andym's knowledge, even new rotors may not be true and it is a good idea to have them turned.

 

There are a number of things that can cause them to warp that is not an existing condition. It is usually driving habits or events that cause it. To name a few:

long downgrades
hot brakes and hitting cold water
Sitting with breaks applied when they are hot long enough for them to cool
heavy load breaking

All of these can do your brake rotors in and not be an existing condition. But you should look for something like a brake hanging up which will also do it.

I forgot to hook up my trailer brakes one time coming down a mountain and that's all it took.

 

I personally would not turn a new rotor, if they are not true, take them back. You can only turn them down so much and that takes away from future turns. I have only had troubles with cheap rotors. Sometimes you get what you pay for...IMO

 

i never did this until reading andym's post to do this.

since then 3 of 6 new ford rotors needed a clean up cut.

ford rotors are not in the cheap rotor category in my book.

 

Agreed, I am supprised that that many were not true though. I haven't tried Ford rotors but have never had a problem with NAPA. I tried some Autozone once and they started out good but seemed to warp fairly easy, but again one event may have caused it.

 

I have yet to purchase a set of import-made rotors that were true. One of the two rotors for my F350 wasn't even machined correctly - the outer diameter was shifted off center by about 1/16". Had I put them on the truck out of the box I'd have poor braking and one side would have wobbled as if the tire weights fell off.

So I skimmed the braking surfaces true and corrected the offset diameter issue on the one rotor, then made the other rotor the same diameter.

While I saved a couple of hundred in purchasing import rotors instead of ford dealer rotors, I easily spent three to four hours making them useful. I have a lathe in the garage so it wasn't a big deal. Just annoying.

And whoever said each skim shortens the life of the rotor - they are correct - if I'd have to take off more than a couple thou I'd return them. The only reason why I didn't return this pair (especially with the one that the OD was offset) was my wife took the one working car, the other car was on jackstands with all the suspension bushings out and my truck well, I had the brakes off so I had nothing to drive to return them and impatiently wanted my truck back on the road because this was a necessary repair that interrupted something I had to do that day.

 

It is not uncommon and in fact is almost always necessary for new rotors be trued up once mounted to the hub.

Differences in the hubs make it necessary, they are not exactly the same, a rotor needs trued to the hubs center with the bearing’s raceways in place that you intend to use.
If you are changing the wheel bearings be sure to install the new race's first. The turning/truing process will not harm the new ones.

 

I agree with the poster who said that Autozone/Advance Auto cheapies start out well, then warp. This happened on my Mustang and I simply removed the rotors with less than 1k on them and returned them. 1 thing I will say about Autozone is that they have a decent no quibble return policy. Only thing is once I got the rotors swapped for new ones I was in the same boat 1k later...oh well....
Jay

 

If I go to trouble to remove a badly warped rotor I replace it <(other will be next)For the price.$30 + And if get turned tell them to clean it up. I had more than one trashed that was new because they (auto parts cranked up machine . ) I now have own machine and know you can clean rotors several times and still be well with in factory specs.

And yes new one r warped allot of times.

 

That depends on how bad they are warped. I've turned some one time and they barely met spec. just to get them true. They were new the year before.

I guess you guys that are turning new rotors either have access to a brake lathe or own one. I have never chucked a new one up to check it. I slam it on and if I can't feel it in the car/truck I'm good to go and so far I've been lucky I guess.

 

If the rotors I'm turning fit on my "regular" lathe I'll use that as it's in my garage. If the rotors don't fit, I take 'em to a local service station with a few bagels and just borrow their machine for a while.

I've even trued rotors on my milling machine in a pinch - certainly the hard way but one has to do what they have to do, right?

For my above comments, remember that my truck is an F350, so the front rotors are absolutely massive - If I catch a serious problem before the pad rivets gouge the rotors I can usually get four or five skims out of them before I have to replace them. And, why on occasion I've had no problem using junkyard rotors - because I measure the thickness before taking them home, and if there's enough meat left I can skim them well within spec and not pay for new import rotors that I have to skim anyway.

Other than the factory rear drums that came with the truck, my rear drums have never been replaced with a new one - always junkyard ones, always plenty of meat to skim them true.

 

I may shop at Autozone for most parts, but NEVER will I EVER skimp on brake parts. Not being abot to go is bad. Not being able to WHOA is much worse. I still have the original rotors on my 92, which have NEVER been turned. I replaced the pads at 130K simply because they had 130K on them. They weren't even close to worn out, but had the infamous grabbing problem. I'd never noticed brake dust on my wheels with the OE pads. I put Bendix metalized pads on, because I trust Bendix brake parts (as do most race drivers), and now my wheels stay black with dust. They brake smooth, and don't grab in damp weather, but what's with all the dust?

On my old 'Bird, I replaced the rotors, calipers, and pads because I had a pulsing problem in the front, which I figured was warped rotor. Kinda figured a 20 year old car would appreciate some new brakes too. The new parts did NOTHING to relieve the pulsing though. The only thing I can come up with is a bent spindle causing a wobble. The Ex wasn't very nice to the car. EVERY set of raised letter tires I put on it had the letters ground off in the first 5K miles because of her curbing them, so who knows what she bent or broke under that car. I had the rotors checked, and they're true and round, so gotta be something up with the spindle. Oh yeah, I changed bearings as well. Not much point in putting new rotors on old bearings.

You CAN get good rotors out of the box, but you're probablly going to pay more for them. I don't mind paying a little more for something I may wind up depending on to save my life. I use Bendix rotors/parts exclusively for brakes, no matter where I buy them (obviously not from a dealer).