Morning Guys,
Recently did my front rotors and brake pads rotors were warped (2009 Acura tl sh awd )... for the first couple of days it was smooth no shaking when braking... but after a week I notice the shaking again especially at high speed 60-80 mph
what could be causing this ? think the rotors warped happen so fast?

 

rotors could be warped again. Did you do a proper brake bed-in process after installation? Did you also ensure your wheels were torqued down properly and not overtorqued?

Did you also check to ensure your brake caliper pins weren't seized?

 

I didn't do the proper brake bed-in process didn't know i have too. so that could have caused the problem ?

 

Many deficiencies can cause vibration.

Wheels our of balance
Front alignment out of spec.
Tire belt issues.
Tire unevenly worn.
Wheels bent or warped
Worn bushings

Try rotating wheels (front to back & back to front) and see if vibration persists.

 

Yes that could. The bed-in process is highly recommended for new pads and rotors. Did you buy OEM or cheap aftermarket parts from stores like Autozone?

If it shakes when braking, pretty much means it's brake related. Not tire or suspension problems.

 

As Reorge pointed out, worn lower control arm bushings can cause steering wheel shaking while braking from high speed. But since the OP just did a brake job it's most likely brake related. And it's likely caused by pad material deposited unevenly on the rotor surface, which the bedding-in process is supposed to prevent, not actual "warping" of the rotors.

 

Rear brake rotors are probably warped.

 

Money on an issue with the brake job if its a new issue. Make sure you dont leave your foot on the brake after coming to a stop if the brake are hot/when youre bedding. Leaves a deposit that will make them feel warped. My tl sh awd had issues woth front rotors being warped as well, swapped em out, bedded appropriately and the problem went away.

Great info in this thread about other causes of wheel vibration at speed.

 

sounds like my problem is there a way to fix it ? maybe trying to bedding them again ? or I have to replace them ?

Thanks in advance

 

google, "brake bed-in procedure" and see if it helps;

 

Seriously, check your rear rotors, or just replace them and install new pads. Unless you have a dial indicator and know how to use it, it will be difficult to measure the run-out. If the emergency brake was ever driven with it engaged, even not enough to turn on the reminder light, or a few high speed stops warped the fronts, it is likely the rears are warped too.

Trust me, I'm a scientist