YACT: Brake problems

[TechnoKid]

Under moderate braking from say 60-45 in my mother's 97 accord EX sedan (car has abs), the steering wheel shimmies/shakes or vibrates a little (from side to side), I'm not sure if there is pulsation in the brake pedal. The steering wheel does not shake/vibrate at any other time; only when braking from ~60+ with moderate pedal effort.

Brembo blank rotors with akebono ProACT pads in the front. These are less than 10k miles old.

Driver's front (front left) rotor surface appears to have some glazing (but no glazing spots or dots) on the outside face, but none on the inside face.

The ProACT pads worked great at first but now this? I know Akebono puts out quality stuff.

I'm going to try and re-bed the pads in tonight when there is less cars on the road and see if it ain't uneven pad deposits or glazing of the pads or rotors. If I cannot fix this myself I'll have my mom take it to our indie honda mech. Maybe the ProACT pads aren't all that great, though I do know the OEM pads are ceramic based like the ProACT.

I doubt its warped rotors because my mom doesn't drive that aggressively. I don't think its sticking caliper pistons. I have flushed the brakes myself (Valvoline synpower) using gravity method and the pedal feel is good.

It did this shaking both before and after I rotated the tires today. I used a torque wrench to tighten the lug nuts to 80 ft.lbs.



I just though of this, could it be the tie-rod ends? But wouldn't it [steerwheel] vibrate all the time then?

Any ideas?

Thanks in advance.

 

[imported_Phil]

Have you checked the balancing?

 

[jagec]

Is the problem worse with hot brakes than cold?

 

[packmule]

If they did not use a torque wrench to tighten the lugnuts it is possible that your rotors were warped. I always insists that a torque wrench is used when putting my wheels on. Alot of shops always whip out the impact and go to town, it may be faster but it will warp new rotors.

If that is the case pull your rotors have them turned and torque them yourself.

 

[TechnoKid]

Balancing of the tires checks out because they do not vibrate at any other time except when braking at 60+ (or at least its most noticeable when braking at 60+).

Pulling rotors on the accords is not a simple task; they are bolted in from behind the hub (sorta), so I'd have to pull the axle, the lower ball joint and the whole spindle/knuckle to take out the rotors. I'd would do it except i dont have a large enough socket for the axle nut. Pic1Pic2

Perhaps I'll just have my mother's honda mechanic solve the problem.

 

[The Stigenator]

Originally posted by: TechnoKid


Perhaps I'll just have my mother's honda mechanic solve the problem.

wise decision.

 

[NutBucket]

Grease your caliper pins.

 

[TechnoKid]

Pressures checked and are ok. 32psi all around.

I regreased the slide pins today, even though they were already free sliding when I took them apart. I sanded the pads with garnet paper and also scuffed the rotor faces, followed with brake cleaner, to remove any glaze or what I thought is glaze.

When I took 'er round in the backroads, the steering wheel still vibrates when braking over 60mph, but it stops just when it reaches 45-50mph. Whether the brakes are hot or cold make no difference.

The brake pedal does not vibrate/pulsate.

I'm starting to think its something suspension related, like when all the weight of the car gets transfered foward while braking, some suspension piece or part is making the steering wheel vibrate. My first guess would be tie-rod ends, but I chekced those and there is no play; they are not loose, unless I am checking them wrong.

As for bedding procedures, when they were first installed, I did some moderate stops, about 5 from 45-10. These ProACT pads are not high-performance race/track pads IMO, so no need for several 60+ to 5 stops.

I am at a loss of what it could be.

Thanks everyone.

 

[Oger]

Warped rotor(s) or loose wheel bearings.