please help! changed rotors and pads but pedal still shakes bad
#16
Registered User
iTrader: (2)
Join Date: Mar 2007
Location: Nor*Cal
Posts: 624
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
it could be the brake yeah, bc i ran into a problem with a customer a while back, we checked everything, new rotor and brake, still the same problem till my boss put the wheel on a wheel balancer and the wheel was really bent which cause the car to shake really bad, try rotating your tire and see how the out come goes
hope this help
hope this help
#18
Lexus Champion
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
Why buy a super quality luxury car and then put junk on it to save a few dollars. Just doesn't make sense to me. I don't want anyone touching my UL except my trusted local Lexus dealer.
Just my opinion.
Just my opinion.
#19
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
According to an article by Stoptech, "warped rotors" are really a myth. Instead, it's the nonuniform depositing of brake pad material on the surface of the rotor from an improper break-in process. Proper way to break in rotors is to lightly brake on new rotors/pads to warm them up, then accelerate hard to 60mph, brake hard (not so hard that abs kicks in, though) down to about 10mph, then accelerate hard again. Do this around 6 times. Applied Rotor Tecchnologies advocates doing this plus driving for 10-15 min to cool the rotors, then repeating another 4 times. After this, you will probaby see smoke coming off your pads from the resins burning off. Gingerly drive home, park in the garage with e-brake OFF, let it sit overnight before driving again.
Assuming it wasn't your rotors, I'd check to make sure the caliper bolts are properly torqued (loose calipers will violently shake when you brake!). If there was any bearing work, I'd make sure they are torqued properly. Improper torque of the lugnuts (like using an impact wrench) can also contribute to the early demise of rotors. I don't even trust the dealer doing my rotors. On my CPO LX, the lexus dealer replaced the pads, but the rotors got that warped feeling within 6 months, and this was with easy braking. I replaced the rotors/pads w/ slotted A.R.T (applied rotor technology) cryogenically frozen rotors w/ Andy Porterfield R4s carbon/kevlar pads. It was DIY over a weekend. That was when I discovered that the toyota dealer that did my front bearing repack ('cause I was too lazy to do it at 60K mi) over-torqued the outer axle nut, and by a LOT! Front wheel had way too much friction from a over-tight bearing. After installing the rotors and torquing everything by the factory manual, my fuel economy rose by 2mpg! Not only this, but the dealer seldom if ever (unless you request) torque the lugnuts by hand with a torque wrench. Usually after getting home, I loosen the lugnuts and torque them by hand. It is now 2 yrs and 22K miles later and the brakes are still excellent, no grabbing, vehicle stops fast. BTW, the ART rotors are substantially heavier than the OEM lexus rotors. IMHO, toyota brakes aren't that great. Honda OEM brakes perform better, but it all varies from car to car. If you're not satisfied with OEM braking, change the rotors and pads to higher performance ones, but be careful that the pad temperature is low enough, as some pads don't grip until they get really hot. IIRC, the R4s pads are rated at 0-1000F, but some pads start at like 400F! If you like the OEM brakes, then replace them with OEM.
Anyways, I have had good results with slotted Powerslot rotors (non-cryo, slotted brembo blanks) with the same R4s pads on my old 4runner. I changed them back in 2002, they were still at 50% 85K miles and 7 years later when I sold the car, and rotors were still true, no grabbing. Before that, the dealer installed some cheapo Napa-like rotors. They warped within a year. In the 7 yrs since I've started doing my own brake jobs, I've yet to have any warp on me. But again, I torque everything by hand to factory specs. The dealer seldom does that. They usually whack away with the impact wrench. You'll never get equally torqued bolts doing that.
Assuming it wasn't your rotors, I'd check to make sure the caliper bolts are properly torqued (loose calipers will violently shake when you brake!). If there was any bearing work, I'd make sure they are torqued properly. Improper torque of the lugnuts (like using an impact wrench) can also contribute to the early demise of rotors. I don't even trust the dealer doing my rotors. On my CPO LX, the lexus dealer replaced the pads, but the rotors got that warped feeling within 6 months, and this was with easy braking. I replaced the rotors/pads w/ slotted A.R.T (applied rotor technology) cryogenically frozen rotors w/ Andy Porterfield R4s carbon/kevlar pads. It was DIY over a weekend. That was when I discovered that the toyota dealer that did my front bearing repack ('cause I was too lazy to do it at 60K mi) over-torqued the outer axle nut, and by a LOT! Front wheel had way too much friction from a over-tight bearing. After installing the rotors and torquing everything by the factory manual, my fuel economy rose by 2mpg! Not only this, but the dealer seldom if ever (unless you request) torque the lugnuts by hand with a torque wrench. Usually after getting home, I loosen the lugnuts and torque them by hand. It is now 2 yrs and 22K miles later and the brakes are still excellent, no grabbing, vehicle stops fast. BTW, the ART rotors are substantially heavier than the OEM lexus rotors. IMHO, toyota brakes aren't that great. Honda OEM brakes perform better, but it all varies from car to car. If you're not satisfied with OEM braking, change the rotors and pads to higher performance ones, but be careful that the pad temperature is low enough, as some pads don't grip until they get really hot. IIRC, the R4s pads are rated at 0-1000F, but some pads start at like 400F! If you like the OEM brakes, then replace them with OEM.
Anyways, I have had good results with slotted Powerslot rotors (non-cryo, slotted brembo blanks) with the same R4s pads on my old 4runner. I changed them back in 2002, they were still at 50% 85K miles and 7 years later when I sold the car, and rotors were still true, no grabbing. Before that, the dealer installed some cheapo Napa-like rotors. They warped within a year. In the 7 yrs since I've started doing my own brake jobs, I've yet to have any warp on me. But again, I torque everything by hand to factory specs. The dealer seldom does that. They usually whack away with the impact wrench. You'll never get equally torqued bolts doing that.
#21
Lead Lap
iTrader: (1)
Join Date: Nov 2006
Location: JP (oki to be precise :D)
Posts: 4,918
Likes: 0
Received 2 Likes
on
2 Posts
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
my last set of expensive crossdrilled trendy rotors were properly broken in, but my big 20" heavy 75+ lbs rims (each) were to heavy for the high performance light weight rotor and ended up warping the fronts very quickly. after a few more of these occurrences i switched back to a stronger blank oem rotor (brembo) and never had this problem again. same companies pads (hawk) but new set with each new set of rotors.
so how does stoptech explain that one???
so how does stoptech explain that one???
#22
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
I assume Stoptech sells brakes and rotors, so of course they'll say that rotors won't warp or they'd be swamped with people who have warped rotors.
Warped rotors are no myth.. rotors do warp and they can warp from new. It's just the variances with metals and the molding process. Things just happen...
Warped rotors are no myth.. rotors do warp and they can warp from new. It's just the variances with metals and the molding process. Things just happen...
![Smilie](https://www.clublexus.com/forums/images/smilies/smile.gif)
Thread
Thread Starter
Forum
Replies
Last Post
SPNinjA
Suspension and Brakes
11
04-20-10 08:32 PM
lexus4jess
GS - 1st Gen (1993-1997)
22
09-15-04 11:47 AM