please help! changed rotors and pads but pedal still shakes bad
09-08-09, 09:39 PM
#1
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please help! changed rotors and pads but pedal still shakes bad
I swear this shop I went to has to be the most in-competent group of idiots ever...I don't even know if I should take it back.
I got new oem pads and new aftermarket rotors replaced about 2 months ago... but now it's starting to shake real bad when I brake. In fact, the brakes just feel like crap.
does anyone know what went wrong ? why is my car still shaking when I have brand new rotors and new oem pads. did they not tighten up the expansion bolts properly ? I also had them bleed the brake system, did they not bleed it properly ?
I got new oem pads and new aftermarket rotors replaced about 2 months ago... but now it's starting to shake real bad when I brake. In fact, the brakes just feel like crap.
does anyone know what went wrong ? why is my car still shaking when I have brand new rotors and new oem pads. did they not tighten up the expansion bolts properly ? I also had them bleed the brake system, did they not bleed it properly ?
09-09-09, 12:16 AM
#3
thats weird if a new pad or even 'aftermarket' rotor would go bad in 2 months. might want to double check if your suspension components are all thighten down correctly. also a bad shock can cause vibration during hevy braking (usually down hill braking).
09-09-09, 04:34 AM
#4
Does it only shake when you brake or all the time? I would check the easiest, to make sure all your lug nuts are tight. Maybe they didn't tighten it properly. Most shops don't hand tighten the nuts first then put the pneu. gun to it, they just put it on right from the start. May times stripping the nuts.
Anyway, if you can't isolate it, bring it to a different to get looked at.
Anyway, if you can't isolate it, bring it to a different to get looked at.
09-09-09, 09:50 AM
#6
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it's only when i brake so it's isolated to the braking system
Does it only shake when you brake or all the time? I would check the easiest, to make sure all your lug nuts are tight. Maybe they didn't tighten it properly. Most shops don't hand tighten the nuts first then put the pneu. gun to it, they just put it on right from the start. May times stripping the nuts.
Anyway, if you can't isolate it, bring it to a different to get looked at.
Anyway, if you can't isolate it, bring it to a different to get looked at.
09-09-09, 10:09 AM
#7
Now that the problem has been successfully diagnosed, go get some quality rotors -- OEM is highly recommended -- and finish the job. 
Serioulsy, this isn't an uncommon occurrence with aftermarket rotors -- even the name brand aftermarket stuff. I can't tell you how many times over the years I've seen this on performance car boards such as Supraforums.com. People keep "warping" rotors -- even Brembo and the like -- and keep scratching their head and asking What's wrong??? Get something of known quality or else it's a crap shoot. Brake rotors look simple enough, but there's more to making a good one than just melting a hunk of iron ore and then machining it.
Serioulsy, this isn't an uncommon occurrence with aftermarket rotors -- even the name brand aftermarket stuff. I can't tell you how many times over the years I've seen this on performance car boards such as Supraforums.com. People keep "warping" rotors -- even Brembo and the like -- and keep scratching their head and asking What's wrong??? Get something of known quality or else it's a crap shoot. Brake rotors look simple enough, but there's more to making a good one than just melting a hunk of iron ore and then machining it.
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09-09-09, 10:46 AM
#8
Its for forging process
Now that the problem has been successfully diagnosed, go get some quality rotors -- OEM is highly recommended -- and finish the job.
Serioulsy, this isn't an uncommon occurrence with aftermarket rotors -- even the name brand aftermarket stuff. I can't tell you how many times over the years I've seen this on performance car boards such as Supraforums.com. People keep "warping" rotors -- even Brembo and the like -- and keep scratching their head and asking What's wrong??? Get something of known quality or else it's a crap shoot. Brake rotors look simple enough, but there's more to making a good one than just melting a hunk of iron ore and then machining it.
Serioulsy, this isn't an uncommon occurrence with aftermarket rotors -- even the name brand aftermarket stuff. I can't tell you how many times over the years I've seen this on performance car boards such as Supraforums.com. People keep "warping" rotors -- even Brembo and the like -- and keep scratching their head and asking What's wrong??? Get something of known quality or else it's a crap shoot. Brake rotors look simple enough, but there's more to making a good one than just melting a hunk of iron ore and then machining it.
totally agree. If it's just during braking, then the rotors, although not that old, are probably warped. Making rotors isn't just stamping out a piece of metal into a circle. It takes the proper mix of metals, forging, and then machining and heat dissipation properties. Don't know how much you got off Ebay, but the rotors are like $108/140 (f/r) at irontoad.com. Not sure why the bigger fronts cost less...
09-09-09, 11:01 AM
#9
In addition to using OEM parts as already stated by others, please pay attention to the following:
Make sure that the hub surface against which the rotors seat is cleaned of any corrosion or debris to help proper seating. The back of the alloy wheels that seat against the rotors should also be cleaned properly.
Make sure that the wheels are torqued properly using a calibrated torque wrench. No air tools or torque sticks should be used in tightening. All lug nuts should be threaded by hand, and then hand tightened using a star pattern in three stages to 85 ft-lbs. This torque setting should be rechecked after driving about 100-150 miles.
Good Luck!
Make sure that the hub surface against which the rotors seat is cleaned of any corrosion or debris to help proper seating. The back of the alloy wheels that seat against the rotors should also be cleaned properly.
Make sure that the wheels are torqued properly using a calibrated torque wrench. No air tools or torque sticks should be used in tightening. All lug nuts should be threaded by hand, and then hand tightened using a star pattern in three stages to 85 ft-lbs. This torque setting should be rechecked after driving about 100-150 miles.
Good Luck!
Last edited by vcheng; 09-09-09 at 11:02 AM. Reason: Spell Check
09-09-09, 11:07 AM
#10
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the problem is obviously rotors, like many have mentioned. a cheap knock off rotor can warp in an hour so it doesn't matter how old or new they are. i wasted a lot of money last year on aftermarket rotor setups on my old gs400. i ended up with a set of oem blank brembo rotors that were like 40$ each. best set of rotors i've ever owned.
there is a valuable lesson to be learned here and i think i6turbo knows what i'm talking about.
there is a valuable lesson to be learned here and i think i6turbo knows what i'm talking about.
09-09-09, 12:39 PM
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09-09-09, 12:41 PM
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yeah what he said ^ ^ ^, plus turning rotors in my past experience was like $100+ and it was cheaper for me to get all new brembo oem blank rotors, which are the best i've come across.