I've got a 1997 Accord SE w/ about 178k miles. It has had front endvibratration pretty bad lately. I know it is not 1) Tires (replaced all fourabout 6 months ago) 2) CV joints (replaced at the same time) 3) Rotors (I just replaced those myself last week to try to solve the problem).
The brake pads are 2 months old and (obviously) have plenty of thickness left.
I don't know if they are somehow warped from the previous rotors...but it really seems that the pads are riding on the rotors and will not disengage. The rotors (both before and after the rotor replacement) get really, really hot and the vibration is not only during braking but also during normal driving. It really seems that the pads are having constant contact with the rotors (as deceleration is exagerated and the car doesn't even move at times when idleing in drive and the brake pedal is not pressed).
I put new brake pad clips in too when I replaced the rotors (thinking that the pads mayhave been getting caught on the old ones and not able to move away from the rotors when the brake pedal is released).
The pads are snug in calliperbutseemfree enough that they should not be bound in anyway to cause this much vibration.
Anyone got any clue as to what's going on here?

 

Sounds like your brakes are dragging.

When you replaced the brake pads you should have cleaned & greased the caliper slide pins. Make sure the caliper canslide properly so the brakes don't drag.

Then you should make sure the new brake pads fit nicely into the caliper bracket without wedging tightly. You may have to file off the paint from the pad backing plate so they don't stick.

 

Your Brake calipers are probably seized up.. if the pad has constant contact with the rotor.. this is most likely the cause. this is happened to me before but on a neon.

any other vibrations could be the cause of a bad alignment.

 

Thanks for the suggestions. I'll try greasing the pins and while I'm at it I'll take the calipers off and see if I can push in the piston. I gather that the piston should be able to move in by hand unless there is some sort of obstruction (dirt and general road gunk) causing it to bind up.It seems to "get better" after the car sits for a period of time or if the brakes are not used for a while...i.e. highway driving without stopping/slowing. The vibration and drag go away. This makes me believe that the piston is just very, veryslow to release pressure.
I did grease the brake clips and file down the notches of the brake pads that slip into the clips to see if that would allow the pads to slide a little easier.
Again, I'll grease the pins and try to see if piston is seized up by pumping it out and then trying to reset by hand.
Any other suggestions? My last resort I guess is to get new calipers...but I really don't want to disconnect brake lines [:'(]
Thanks again.

 

You're talking about the front brakes, right? The pistons in thefront brake calipers should push directly in.

For benefit of other people who read this, the REAR caliper pistons don't push directly in. Because of the handbrakeauto-adjust mechanism, you have to spin the pistons in, like they were threaded.

 

you won't be able to push the frt caliper pistons back in by hand ,,

have you or anyone replaced the brake master cylinder recently ??

when you replaced the rotors you got eveything tight ?? did you double chk your work ??

was the vibration there before ?? or did it show after the work that you did ??

have you bled the brake system yet ?? do the brake lines going to caliper look ok ?? kinked ??

 

The vibration was there before I undertook this task, which is why I assumed it was the rotors. The rotors are original...and been resurfaced once...maybe twice. I know they were at the end of their lifespan so I just got some new ones. The brake lines are not kinked so I would think the brake fluid should be flowing back out of the piston just fine, and there is no visible damage to the lines. There are no soft spots when I apply the brakes so I wouldn't think there is air in the line, and likewise the brakes act without hesitation or pumping when the brake pedal is pressed so this makes me believe the master cylinder is fine.

 

I've heard of brake hoses that deteriorate inside, & act a bit like a check valve. They don't allow fluid to flow back to the master cylinder. Keep that in the back of your mind after you rule out any other stuff.

Another one... I don't know if there's any reason to think your brake pedal pushrod length adjustment has moved?? The master cylinder piston has to be positioned at just the right spot to open up a vent allowing fluid to push back into the reservoir. If you lengthen the pushrod (inadvertently), that vent won't open up & the heat of driving will expand the fluid & apply the brakes.

 

Jim I have seen the brake hoses act just like as you are saying ..not in many occasions ...

As for the push rod lenght it cannot be adjusted ( inadvertently ) you need to adjust it from under the dash , you need 2 tools to adjust it, 1 to loosen up the lock nut , the other to hold it from spinning ,, but i have seen a lot of aftermarket brake master cause the same issue that he is having ,, they do not adjust the pushrod properly, they have it too long thus after a few miles of driving , it is the same as if driving with the brake pedal applied ..
it might be a very good idea to shorten the pushrod lenght a bit and see if that helps , you need a 14 mm and a pair of pliers,as i said the adjustment is done under the dash at master cylinder and brake pedal ,,, loosen up the 14 mm lock nut ,you need to hold the wheel nut from spinning otherwise the lock nut will not loosen up , it will just spin,,once loose then with the pliers turn the other wheel nut accordingly ,,

 

check your exhaust piping sometimes they can get stiff somewhere and vibrate the hell out of ur car