DBA slotted rotors warped after only a year (1 Viewer)

[Spook50]

I used to have a pair of DBA 4000 rotors on the front of my 62 that worked outstanding and lasted about 10 years. So early last year I went with DBA again when it was time to install new rotors. Well the new ones have seen very little service (and I'm not heavy on the brakes) and my brakes are pulsating when braking lightly, a telltale sign of warped rotors. Has anyone else had this issue with newer DBA rotors? I hate the idea of having to replace rotors again already, but I see very little choice in the matter here.

 

[3_puppies]

how long has the rig sat? the rotors can also get a spot on them where the pads rest when a rig sits for a long time. Just went thru this on a 100 series that was working on.
had rotors turned and installed new pads, all good now.
my cost for turning the rotors was $25 or so, total.

 

[TRAIL TAILOR]

how long has the rig sat? the rotors can also get a spot on them where the pads rest when a rig sits for a long time. Just went thru this on a 100 series that was working on.
had rotors turned and installed new pads, all good now.
my cost for turning the rotors was $25 or so, total.

A quicker way to see if its just pad/corrosion spotting is hit the rotor with 400-600 grit paper by hand. Most of the time you can see where the pad has allowed moisture to rest on the rotor causing pitting. I've bought many vehicles over the years where this has occurred. If the pulsing goes away, like Paul said, get them turned. If pulsing is still noticeable, order new rotors.

J

 

[Spook50]

how long has the rig sat? the rotors can also get a spot on them where the pads rest when a rig sits for a long time. Just went thru this on a 100 series that was working on.
had rotors turned and installed new pads, all good now.
my cost for turning the rotors was $25 or so, total.

Since installing the new rotors it hasn't sat for more than two weeks at a time. Once I get a chance to pull the front end apart (can't do anything on my truck where I'm currently living) I'll hit the rotors with some sandpaper and see where that gets me.

 

[TRAIL TAILOR]

Since installing the new rotors it hasn't sat for more than two weeks at a time. Once I get a chance to pull the front end apart (can't do anything on my truck where I'm currently living) I'll hit the rotors with some sandpaper and see where that gets me.

Once I get moved and settled in you are always welcome to come by and wrench when needed!

J

 

[red66toy]

Dang I just ordered these! I hope it's just a case of the pads resting too long and not warping

 

[TRAIL TAILOR]

Dang I just ordered these! I hope it's just a case of the pads resting too long and not warping

Don't think that's going to be the case here. 2 weeks is not enough time to describe the affect I'm referring to. I'd say a warped rotor. Other thing that it could be and worth a check if you haven't been into the knuckles in awhile is bad wheel bearings. They can act similar as well.

J

 

[Spook50]

Once I get moved and settled in you are always welcome to come by and wrench when needed!

J

I'll take you up on that!

I'm crossing my fingers that I'll get my house back and be able to use my shop again, but wrenching with a fellow cruiserhead is always a good time.

I'll retorque my wheel bearing nuts as soon as I get the opportunity and see if that may be the cause. It'd be nice if it's not the rotors. I did the knuckles at the same time I changed out the rotors, a little over a year ago. Installed the thicker axle nuts that use a screw-on lock ring too, so no need to worry about the OEM lock washer.

 

[red66toy]

Found this http://legacygt.com/forums/showthre...l?s=606a5c9d92f775891242d2a60f812372&

 

[Cruising Canuck]

It's actually very rare for rotors to warp, usually that warped feeling is from excessive pad material impregnated into the rotor itself.
What causes this is a pad lightly dragging on the rotor which will heat up alot, then when you stop it will impregnate the rotor with pad material in one specific spot. That spot will grip significantly better than the rest of the rotor, causing a pulsing or warped feeling.

Take it for a drive at speed for like 15 minutes, find a nice country road. Then pull over somewhere and feel for excessive heat from one of the front wheels.

Excessive heat means it's dragging, by by tapping on the rotor you will give yourself a second degree burn if the pads are dragging.

If the pads are dragging you have to ensure the pistons are in good working condition and that the pads can slide freely in the caliper.

What reevesci said is also 100% true, give that a shot as well

 

[FJ60Seth]

Improper lug nut torque? Raybestos Brake Tech School, Part One: Rotors Don't Warp | Hendon Publishing

 

[Spook50]

It's actually very rare for rotors to warp, usually that warped feeling is from excessive pad material impregnated into the rotor itself.
What causes this is a pad lightly dragging on the rotor which will heat up alot, then when you stop it will impregnate the rotor with pad material in one specific spot. That spot will grip significantly better than the rest of the rotor, causing a pulsing or warped feeling.

Take it for a drive at speed for like 15 minutes, find a nice country road. Then pull over somewhere and feel for excessive heat from one of the front wheels.

Excessive heat means it's dragging, by by tapping on the rotor you will give yourself a second degree burn if the pads are dragging.

If the pads are dragging you have to ensure the pistons are in good working condition and that the pads can slide freely in the caliper.

What reevesci said is also 100% true, give that a shot as well

I hope a stuck caliper isn't the case. I did complete rebuilds on both front calipers when I did my brakes & knuckles last year. And new 4Runner calipers are expensive from Toyota

 

[Dynosoar]

x2 check the wheel bearings. I have resolved many brake pulsing problems with a simple bearing adjustment.

Dyno

 

[lovetoski]

Found this http://legacygt.com/forums/showthre...l?s=606a5c9d92f775891242d2a60f812372&

We had both a Passat (POS!!) and a Legacy that had brake pedal pulsing. Rebedding the pads as described in the link that red66toy posted fixed it everytime. Dealer said we had warped rotors, and needed new ones. My fix was free, and easy.

 

[Stoshu]

X3 on properly bedding the pads and rotors. Ask any racing team and they will tell you the same. Absolutely critical to cool the rotors back down after bedding them in with a 5 -10 mile drive with minimal braking or you will get pad transfer to the rotor again. Been doing this for 10+ years and haven't had the dreaded pulsing since.

 

[Spook50]

I'm honestly hoping it's the bearings in my case. There are no good places here to do a good proper bed in unless you're out after midnight.

 

[lovetoski]

I'm honestly hoping it's the bearings in my case. There are no good places here to do a good proper bed in unless you're out after midnight.

Not easy in Seattle either, I do it very early in the morning.

 

[red66toy]

What streets do you use? I was wondering where to do this myself when the time comes.

 

[franklin40]

also check your real brakes. i had some troubles with my diff breather being plugged and the little extra pressure caused oil to leak out my rear seals onto my shoes. the rear brakes weren't working well and the fronts did all the work which was enough extra load to warp them. not saying your rear seals are gone necessarily but a well balanced system from front to back is necessary to make them work right

 

[Skniper]

Hmmm... Very interesting and informative thread. I have never seen brake pulsing or "warping" described this way.

Getting ready to refresh my front brakes. I need to rebuild a leaky caliper, put in new OEM pads, and have two brand new OEM rotors in the box waiting install.
Based on this info I'll probably just have the existing rotors lightly turned (if within spec) and save the new rotors for a rainy day. Sure makes for an easier job not having to press out/in all the studs. Will have to reset bearing preload/torque anyway doing this job.

So, with new pads and rotor surfaces...is it really necessary to break in or bed the new stuff?? I've done lots of brake work, never done this.