Poor Quality Rotors

Thanks Michael,

I had seen these mentioned on this news group but haven't heard any testimonials. I was contemplating Performance Products Power Slot Brake rotors, but am a little skeptical regarding some of these products quality.

Jerry

I find this thread interesting. I don't live in a big city, and don't drive in stop-n-go traffic every day. I do drive fairly aggressively; I don't get passed by many.

My '98 Explorer has 97,500 miles on it. It has the original front and rear rotors on it. I did its first brake job, front and rear, at about 68,000 miles. It didn't have to do it then, but it was time. Machined the rotors, new Ford pads, and it should be good until 130K+.

The only thing I can think is that I actually see the stop sign or traffic light ahead, let off the gas, and start applying the brakes at some reasonable distance. Or I got one of the magical "good ones".

It does weigh over two TONS. It's not a sports car. The brakes are pretty good... they've impressed me a few times when I needed them. I don't make it a habit of *needing* them at every stop sign, however. :-)

Jack

A big culprit for warping rotors isn't because they are bad quality, but folks who improperly install the wheels.

Not torquing them properly, will cause warpage to *any* rotor... I've seen guys toss the wheel on and hit it with an impact wrench, and not even bother to tighten it in a star pattern !

Bingo, Chief

And binding of brake pads will warp of too. On the 92, we get to grease the caliper slide pins every now and then to prevent this. I don't know what the

"Michael Johnson, PE" wrote in news: snipped-for-privacy@comcast.com:

I just ordered some a couple weeks ago, they were not in stock. But I should be getting them any day.

Zammer

I've had even better results with my 97 Explorer. It has 96,000 miles and I just had the pads and rotors turned for the first time. The front pads couldn't have had more than 2 mm left on them, rears still had a little. I bought the truck used with 29,000 miles so I'm quite sure these were the original pads.

What do you suppose this means?

"Slotting our rotors adds additional cooling by aiding the out-gassing effect..."

As I understand this... Outgassing means that there's a gas made when the pad is pressed to the rotor. This gas will reduce the effect of the pad, causing a need for more pressure to ovbercome the gas, which in turn increases the heat output, increasing the gas output, increasing the need for more pressure.... Slots give an escape route for the gas, keeping the temps down.

I'm not sure how much this actually helps during normal driving, but in severe use, it's a definite help.

My '92 has 141K miles and I will be having the front rotors replaced this Saturday, for the 1st time. I replaced the rear drums last year at about 120K, also for the 1st time. Both had been turned regularly.

Dan

Ford TSB recommends against turning them unless absolutely necessary. Sandpaper instead.

That TSB came out pretty recently, IIRC. Most of the shops I spoke to (mine included) still recommend turning the rotor. I asked specifically about the new rotors that will be going in and was told that the manufacturer [Bendix] recommends turning.

If I start doing my own brakes I will sand the rotors. I don't have a lathe or mill to turn them on and if I have to lug them somewhere it wouldn't be worth doing my self.

I would like to know what the hell happened to the durability of brake rotors and drums in the past 10 years. For my entire driving life, until very recently, turning drums and rotors has been the normal recommended procedure. Even having them turned as part of every brake job they would typically lasted 100K miles or more. Rotors and drums that only last 50K miles under normal use is bullshit.

What happened was the drive to lighten everything to improve fuel economy. Lighter rotors are thinner. Lightening rotating parts provides a double whammy of improvement. Still, I have never actually had a set of rotor warp. I also think the idea that rotors always need to be turned as part of a brake job is definitely old school. I am freindly with a local mechanic who always turns rotors and drums. I asked him why. He said that was the "right" way to do it. In my mind the "right" way is to check the runout. If it is within spec, all you are doing by turning the rotors is removing valuable material. If the runout is out of spec, I throw the rotor away and get a new one. A properly manufactured rotor should be at least as good as one turned by a local mechanic (and probably better).

Whoever claimed that Bendix recommends turn17 Q. Do rotors need to be turned on every job? A. If no excessive pulsation, lateral runout or surface scoring exists and physical dimensions of the rotor are within manufacturer's specs, rotors machining is not necessary.

Regards,

Ed White

Actually, the don't-turn-rotors TSB is many years old, though I think Ford has reissued it every now and then, just like the one reminding the techs to torque the lugs. As C.E. points out (and he is way smarter than I am), if there is no warping or bad scoring, turning only makes them thinner.

Turning is just something mechanics do because it is something mechanics always have done.

Gee Ed, if you are going to interject actual facts and written proof into your posts, how the heck we gonna get a good argument going on this group :o)

Thanks for posting that. Very interesting.

Thanks for the info, I'll be printing the page and talking to the shop about this.