steevr

Anyone else have problems with warped rotors? My '02 has 16,000 miles on it. The other day I had to hit the brakes fairly hard while driving 65 mph on the tollway. The ABS kicked in slightly in order to avoid the wheels locking up and I was off the brakes by the time I was down to 25 mph. Ever since then, I'm starting to feel the vibration while braking. I don't notice any shake in the wheel, but rather feel it in whole car itself while braking. You notice it the most from 40mph down to about 5mph.

Sounds like I'll have the dealer check it out at the next oil change.

salimshah

What you described was ABS working.

Warped rotors is pulsation of brake pedal in a "non emergency" braking. .... Gentle slow down with soft pressure on brakes. ... Note this pulsation is a symptom, the real check is putting a guage on the the rotor and spinning them around.
Salim

steevr

The pulsation I'm feeling in the pedal and in the car itself IS during normal braking, it's not the ABS. The ABS kicked in during the original panic stop.

One of my previous cars had the warped rotors replaced and this is exactly what it's feeling like during normal braking.

salimshah

Stever:

The only issue I have with Lexus rotors is that they get rust spot (once exposed to water ... even wash). These spots make sound on braking and the brakes grab a bit. But this thing goes away quickly after couple of stops.

Warped rotors have been attributed to improper (over) tightening of wheel lugs. Excessive temprature swings "heavy braking" and getting spashed with water/snow.

turning the rotors essentially makes them more thin and more susseptible to warping.

Good luck.

Salim

gp1200x

Join the club...happens to me all the time on every vehicle. I am actually trying to get a friend to buy a rotor cutting machine. They charge $20 a rotor here...ripoff.

I haven't decided yet if I will turn mine on the SUV or replace them. $80 for turning them would make a dent in the price of high quality set. Car manufacturers should give buyers the option of getting high performance brakes vs the substandard cheap (tempered??) steel that warps the first time you heat them up.

You will do something in the end since it doesn't fix itself. If you replace your rotors with high quality oems, give us the price and make. No one guarantess that even high quality ones won't warp....why not???

www.rockauto.com sells various replacement ones.

ederny

Stee... Either turn the front rotors, these are the ones that usually warp since they take most of the braking force (65% or more) or buy good ones for the front. The problem is if you sometimes need to make rapid stops, especially at above 50 mph (e.g. 65 to 25 in an emergency situation like here with Boston drivers), you could easily warp the fronts.

There is a tremendous amount of energy (momentum) that must turned into heat at high speeds (something like the energy increases to the square of the speed), so standing on the brakes at 70 down to a stop is very hard on the rotors especially with uneven torque on the lugnuts or a dirty mating (rust/sand) between the wheel and rotor hub.

laterldf

Warped rotors on ES300's have been common. My wife's car (2002 ES) had to have them replaced at 8k but the problem presented itself much earlier. Sounds like the same problem on the RX's. later, ldf

Chuckieb

Maybe this is a Toyota/Lexus problem? The rotors on the RX are OK so far, but we are about to replace the rotors on my wife's '91 Celica for the second time in 125,000KM,s and I replaced the rotors (all 4) on my Supra at least twice in the 7 years/180,000 km's I owned it. So I always had the impression it was something I was just going to have to live with.

Or maybe it's an operator problem? Do other makes not have similar problems?

ederny

Chuck, it's all in the rotors, material, design, etc. For example my 85 Mercedes had 275,000 miles and only changed the rotors once at 125 miles due to wear - never warped. My 911 has nealy 200,000 and never had the rotors replaces. Never a sign or warping in either.

The average vehicle today has marginal rotors designed for soccer mom. If you want performance, you have to pay extra (i.e. high performance rotors). Otherwise, just drive like Mom and your rotors will last.

parula

Ed, what kills the rotors, high speed breaking and excessive heat, or repetitive moderate speed breaking?

Any idea why it may be so difficult to make a universally resiliant rotor??

ederny

Well, it's not too hard, just the material and thickness (mass) is key. Lexus could do it easily - it's a cost issue (don't forget the RX was not meant to be a "performance" vehicle, it is an LUV.

Warping comes from the temperature it reaches and the amount of time at that temp to a lesser degree. So you can do one massive panic stop from 75 MPH and cause a problem, especially if they were already warm. Or you can do many hard low speed stops and get the same effect. At the extreme you could crawl along at 15 MPH with your foot on the brake and over heat them in a 1/4 mile - you've seen people ride their brakes - right? Not a good thing if you want to avoid warping. Going down steep grades (I was in the mountains this past weekend)- yikes, use a lower gear! Switch off O/D to shift out of 4th into 3rd (best to do before you build up speed - don't over rev).

Keep in mind the temp of the rotor goes up as energy is put into it (pads rubbing). The harder the braking (rubbing), the faster the kinetic energy (motion) of the vehicle is put into the metal of the rotor. Temp climbs fast when braking from a higher speed because of all the kinetic energy. Temp drops when air blows over the rotors - one of the important aspects of drilled rotors is better cooling. This is why the front rotors are usually hollow in the middle (between the 2 plates). Also why racecar have ducted air to the rotors.

Maybe we need a group buy of some performance rotors for those of us who want a bit more performance….

JRB

I have also read that cool water on hot brakes will lead to warping. Not a good idea to rinse your car (wheels) with a garden hose or go through a car wash immediately after a long or spirited drive.

ederny

Add to the list a safer way to cool down - drive at a reasonable speed after hard braking (with little additiomnal braking) for a few minutes (5-10) to cool the rotors. Stopping with rotors at a high temp will cause uneven cooling (like the water above) and contribut to warping as one part cools faster than another (bottom vs. top and the brake pad will hold a hot spot on the stopped rotor).