Guidance with brake rotors

I consider myself pretty well versed with brakes... at least on the hydraulic/engineering side.  One thing I can't seem to do is find the right pads/rotors.

The F150 I just sold, I had put really good rotors on it and ceramic/semi-met pads.  I did a proper bedding.  A year later, the pulsing was so bad I had to replace the rotors.  Similar thing happened with my Impala SS.  I got the heaviest, thickest rotor I could find and top shelf pads and did a proper bedding.  They lasted about a year and a half before the pulsing became very frustrating.  When I bed pads, I do a cycle of threshhold braking from 60-5 mph, 40-5, then 30-5, repeat the same thing one more time, then drive it for 20 minutes or so without ever coming to a complete stop with the brakes.  I usually get a faint whiff of hot brakes and I know they're hot enough.

The new-to-me 94 Fordzda Branger I just got has a pretty good shimmy (which I knew when I bought it from a used car lot).  Looking at the brakes, it appears they put new pads in it to sell it but the rotors look older.  So it's no wonder that has a shimmy. 

So, when I'm looking for rotors, what do I get that doesn't suck?  Is there something I'm doing wrong with my bedding procedure?  Is it my choice of pads?  I usually get organic pads for appliance cars and ceramic/semi-met for things I care about.  Since these pads are one month old and I'll re-use them, should I re-bed them with the new rotors? This truck is a DD that hauls lumber and sometimes tows 4000 lbs.

I've had very good luck with Centric rotors from Rock Auto. They have survived Lemons, DD in traffic 50K miles a hear, and towing without issue. I run them on everything now. 

In reply to Toyman01 :

+1 on centric rotors from rock auto, from DD-towing-track duty, they do it all very well. 

The set on my dd are coming up on 100K with no vibrations. 

I buy the cheapest rotors I can find and best pads. Proper bed in and roll. The ONLY car I ever had a problem with was the old Elantra but taht was a 2900lb car with 9.9" front rotors and rear drums. It would actually turn the rotors blue. 

The TSX develops a fairly pronounced shimmy over the life of the brakes.  It starts out fine.  In 15,000 miles you can feel it a little.  In 30,000 miles it's bad.  It did it on the OE brakes.  It did it with the Brembo / Akebono replacements I put on and properly bedded in.

What I found when I put the third set of pads / rotors on the front is that the inside surface of the rotor was pretty darn rusty at the margins, and the unmachined part near the back side of the hub was really rusty.  Like, really rusty, enough that it could either have put the rotor itself out of balance, or could even be jiggling the caliper via the pads. 

So I bought Centric high-temp coated rotors this time.  Hopefully they won't rust the same way the raw iron ones do on the inside, or at least not as soon.

I have been buying the Raybestos Advanced Performance rotors lately and could not be happier.  I used to buy Brembos, but the last set wasn't so hot.   Before that I always bought Bendix and was happy, but I'm not sure they are still doing rotors.   

Given the consistency across vehicles and the time frame it sets in, I'm wondering whether you've got some driving habit that's causing problems. But that is absolutely not based on great knowledge of brake troubleshooting.

Interesting:

http://www.hendonpub.com/resources/article_archive/results/details?id=1787

jharry3 said:

Interesting:

http://www.hendonpub.com/resources/article_archive/results/details?id=1787

This is something that I have talked about for 20 years and people look at me like I have apple trees growing out of my ears.

Rotors actually do warp, but it isn't the primary reason for pulsing brakes.  It can cause some pulsing, but on floating calipers, a warp doesn't really cause much pulsing since the rotor just follows the runout.

The real reason for pulsing (and the real reason you want to properly bed pads) is inclusions as this article talks about.

Probably, you are doing something wrong.  Do they sit for extended periods, creating a rust patch?  Do you come to an aggressive stop, then sit at a light with your foot on the brakes?  Do you buy stuff built in the 80's and 90's before manufacturers realized that having adequate brakes was important? 700 Volvos needed rotors every other day.  V70's don't.

Or, do you notice a shudder that most of your friends wouldn't sense?

I didn't know bedding in brake pads on street cars was a thing. Something new every day I guess.

Never had a problem with brakes on my cars running centric cheapies on everything, but I am usually very light on the pedals. 

I don't generally have problems, but I also tend to run fairly aggressive pads, even on street cars.  So I usually go through 1 - 2 sets of rotors to a set of pads, meaning the rotors are usually getting shaved down enough to avoid any issues. 

I just stick with NAPA.

Never a problem.

Centric cheapos have worked well for me so far, and I beat on them hard at the track.

Reverse the  bedding methodology.

I start at slow speed and work my way up way up per the manufacturer’s directions. I start at 35 - 5 and repeat several times. I don’t want to get them too hot immediately.  Then I increase to 45 and then 60, repeating progressive stops. 

Streetwiseguy said:

Probably, you are doing something wrong.  Do they sit for extended periods, creating a rust patch?  Do you come to an aggressive stop, then sit at a light with your foot on the brakes?  Do you buy stuff built in the 80's and 90's before manufacturers realized that having adequate brakes was important? 700 Volvos needed rotors every other day.  V70's don't.

Or, do you notice a shudder that most of your friends wouldn't sense?

I would love to think it's my fault (that isn't sarcasm).  The F150 was driven every day for 60-ish miles a day.  The SS was driven a few times a week.  I drove the F150 like a grandfather who retired from teaching driver's ed; primarily because I am a super chill driver, but also because I was ticked at the 12 mpg.  In general, I'm one of those people who drives the speed limit, uses turn signals at the proper time, and stops for pedestrians in crosswalks.  The only thing that separates me from the driver's ed grandpa is the fact that I don't roll down the window and give hand signals when turning.  That is not far from the truth.  I can hoon with the best, but on the street I'm chill.

The shudder in the F150 was enough that it would splash coffee out of the sip hole in my gas station coffee cup.  It was bad.  You're right... I want to think its me - either my driving style or my choice of parts.  Just trying to get to the bottom of it.

In reply to tester :

I just ordered some Centric rotors.  I'll try your bedding idea.

I bed by driving at 35 mph with a foot on the brakes until they smell.  Then a couple miles to cool them off.  Never had a problem until I bought cheapo rotors from Advanced auto for a suby.  Actually two, both legacies.  In a year they both pulsed bad.  Replaced with ones that were guaranteed and the pulse went away.  

For the Hawk pads, I followed their bedding procedure, which I forget.

 street pads, I just do a few miles in traffic.

A legit bedding procedure ranges from 50 to 200 stops, depending on actual customer requirements.  Speed ranges from 40-60 mph down to zero.  Initial rotor temp about 100*C for each stop.  Deceleration range 0.2 g to 0.4 g depending on customer.

and a rotor with more than 50 microns of lateral runout can indeed develop pulsation because in order for the caliper to "follow the runout", there will be pad to rotor contact, alternating inboard - outboard - inboard - outboard at the max runout points on each face of the rotor.  This knocks down the (local) high spots, which makes the disc thinner at each of those spots.  And now we've got brake torque variation due to disc thickness variation.

In reply to Duke :

We used to paint the rotors and calipers on all the cars that got brake services at the dealer for just that problem. No complaints. 

My bed in is 2-3 35-5 hard-ish stops, then 45, then 60 which makes them really hot and smelly. I finish the "drive around the block" (in my case is 3 more miles) to allow them to cool and they're good. The truck has a pulsation but I had an issue with a seized caliper pin causing it to hangup. No surprise there. Eventually I'll get another set of Hawk LTS and some new rotors when I get sufficiently tired of it. 

bobzilla said:

In reply to Duke :

We used to paint the rotors and calipers on all the cars that got brake services at the dealer for just that problem. No complaints.

Yeah, until last fall the car was DW's DD, meaning every day it went 3 slow miles one way, parked, 3 slow miles back, parked.  It only ever got any real use on weekends.  I assume that the brakes never really got warm enough to bake the moisture out.

It's also why I'm currently getting the timing chain, guides, and tensioner replaced on a K24 with 75,000 miles on it.  But that's a different thread.

Ford makes a HD pad for there trucks. I have used it a couple times with no issues. I don’t remember what rotors I was using. May have been OE as well.