car shaking while breaking

[LiquidK]

the check engine light is on too, im going to go pull the codes today but i think the two problems might be unrelated

i'm thinking its probably brake rotors, but the old owner said the front control arm needed replacing, could that cause the shaking?

[89s1]

Usually a shaking under braking is a warped rotor(s). Done any emergency stops or heavy braking recently?

That being said, loose suspension components can cause all sorts of problems, but usually a bent control arm will make the car pull one way or the other and the only other way a control arm can go bad is if the bushings crap out. If that happened there would be a bit of clunking from that corner over bumps.

Hope this helps.

[misterrick]

Originally posted by LiquidK
the check engine light is on too, im going to go pull the codes today but i think the two problems might be unrelated

i'm thinking its probably brake rotors, but the old owner said the front control arm needed replacing, could that cause the shaking?


if the bushings in the control arm were shot, it would probably vibrate more than just while braking

what kind of vehicle? in a honda, im assuming you drive a civic, something in the front end would NOT throw a code (maybe ABS) but im not so sure of other manufactuers.

[LiquidK]

hmmm yeah thanks guys. its probably the rotors and a seperate problem for the obd2, ill have the code checked tonight

yeah, it's a honda, everything seems to be running fine with the exception of the vibration.

6th gen accord

[jdm_eg6]

yeah, if your car is shaking while breaking i would be worried man, but if its shaking while braking then its probably the rotors. ;) thought i would be the first.

but i would be highly confident in the rotors, other than that checking your codes is easy! Look it up online all you need is a paperclip and eyeballs.

[RickDaTuner]

A damaged or worn out lower control arm will cause a vibration when the car is coasting at a steady speed, it is usually instigated by an uneven road or traveling over moderate bumps, a damaged unit is further noted by a slight pull.

Shaking under braking is almost always related to varying thickness rotors, or what everyone commonly calls warped rotors.
This is caused by a few things one is unequally torqued wheel nuts, ceasing brake calipers, or also, but not limited too brake transfer material on the rotor.
Warped rotors can also be caused by varying temps on the rotor surface, leading to dissimilar wear on the rotors, this can be caused by any contaminants such as oil, finger smudges, grease, or brake fluid.

One very common one, as stated is finger smudges. If you take a laser thermometer and have one clean rotor and one with finger prints on it, then do about 3 50-0 stops and take the temp of each you will see that the rotor with the finger prints on it can be up to 100deg hotter/cooler(depending on the contaminants) than the other one, that is in extreme circumstances though. This is why when you do a clutch job or brake job you never touch the rotor surface or the brake pad material, and if you do, you always wipe it down with brake cleaner.
Finally warped rotors can be the cause of a hub with to much lateral run out. Rust and other foreign material on the hub can cause it to rotate out of true, resulting in excessive strain on the caliper and bracket. Leading to one area of the rotor having less material than the other, which is basically all that happens when you feel the hard pulsation on the brake pedal

Long reply short, I would replace your rotors, lube your caliper sliders and remove any rust or corrosion thats on your front hubs before installing new ones, finalize it by torquing your wheel nuts to the appropriate ft/lbs setting

and the CEL is unrelated.

[RickDaTuner]

haha in the time it took me to type my reply, 5 people answered your question... LOL

[LiquidK]

thanks guys, you've been alot of help
i'm going to bring it to a shop this afternoon, if anyone has any recommendations on where to take it, id be glad to hear it (im also getting the rear barrings replaced),and i know alot of shops will try and take advantage of the fact that im not 100% sure of what the problem is

[jdm_eg6]

hmm.. I know D&K automotive in the SE is very good. the dont bs and are experienced with even local rally cars .etc and euro cars mostly. But they have no issues with the japs either.

[PremiumRSX]

Is everything suspension-wise nice and tight?

I would associate cracked rotors/pad deposits(I do not believe in warped rotors) with vibration through the steering wheel and brake pedal.

Car shaking I'd associate that more-so with worn suspension components. Perhaps wheel bearings or bushings or other.

[LiquidK]

replaced pads and rotors, they were pretty warped.
also replacing rear bearings tommorow and the front right control arm, suspensions a little iffy and there's a bit of roaring from one of the rear wheels.

the only issue im unsure of is the CEL
the codes i hit are p0301 (cylinder 1 misfire) and a code for cylinder 2 misfire, as well as a vtech malfunction.
i replaced the plugs and checked the wiring, no dice, so im thinking it might be the ignition coil or cylinder pressure? anyone else have any ideas?

[Schwa]

Check the distributor cap and rotor as the contacts commonly become corroded.

[Diocletian]

Originally posted by RickDaTuner
A damaged or worn out lower control arm will cause a vibration when the car is coasting at a steady speed, it is usually instigated by an uneven road or traveling over moderate bumps, a damaged unit is further noted by a slight pull.

Shaking under braking is almost always related to varying thickness rotors, or what everyone commonly calls warped rotors.
This is caused by a few things one is unequally torqued wheel nuts, ceasing brake calipers, or also, but not limited too brake transfer material on the rotor.
Warped rotors can also be caused by varying temps on the rotor surface, leading to dissimilar wear on the rotors, this can be caused by any contaminants such as oil, finger smudges, grease, or brake fluid.

One very common one, as stated is finger smudges. If you take a laser thermometer and have one clean rotor and one with finger prints on it, then do about 3 50-0 stops and take the temp of each you will see that the rotor with the finger prints on it can be up to 100deg hotter/cooler(depending on the contaminants) than the other one, that is in extreme circumstances though. This is why when you do a clutch job or brake job you never touch the rotor surface or the brake pad material, and if you do, you always wipe it down with brake cleaner.
Finally warped rotors can be the cause of a hub with to much lateral run out. Rust and other foreign material on the hub can cause it to rotate out of true, resulting in excessive strain on the caliper and bracket. Leading to one area of the rotor having less material than the other, which is basically all that happens when you feel the hard pulsation on the brake pedal

Long reply short, I would replace your rotors, lube your caliper sliders and remove any rust or corrosion thats on your front hubs before installing new ones, finalize it by torquing your wheel nuts to the appropriate ft/lbs setting

and the CEL is unrelated.


It's not often that I read a post from someone who actually understands brake components - cheers!

[Kloubek]

Originally posted by LiquidK
replaced pads and rotors, they were pretty warped.
also replacing rear bearings tommorow and the front right control arm, suspensions a little iffy and there's a bit of roaring from one of the rear wheels.

the only issue im unsure of is the CEL
the codes i hit are p0301 (cylinder 1 misfire) and a code for cylinder 2 misfire, as well as a vtech malfunction.
i replaced the plugs and checked the wiring, no dice, so im thinking it might be the ignition coil or cylinder pressure? anyone else have any ideas?

Just went through an ignition issue with my gf's car.

Changing the plugs and wires was a good start. I too would be willing to bet a corroded distributor.

[EFHatch]

I think his accord has a distributor less ignition system so it might just be the ignition coils.

A simple way to test is to move one or both of the problem coils around and see if your getting the same codes on different cylinders. If you are you know its the coils and should be replaced.