Shake on Brake

[Best Sho]

Hi,

Lately when I come off the northway and gradually apply the brakes off / on.
Their a shake, big vibration in the front of the car, can feel it in steering wheel, brake pedal. The front of the car can see it shake.

The front brakes were done last year (rotors and pads). It only when pressing on the brakes the faster your going the more it is.

Any ideas.....warp rotors, cv joints, tied rods, rack & pin, ummm don't know. But I'm think warped rotors.

Thanks, Mike

 

[oh_SHO]

I would guess warped rotors. Does it smooth out a little if you brake real hard? That would point to rotors too. Its cheap enough to have them turned so I would start there.

 

[Bizzy]

My guess is warped rotors as well. Premature warping can be caused by a few things, but the most common cause that I know of is overtorqued lug nuts.

 

[sdpatt]

That is usually the indication of a warped front rotor or rotors. You can have them turned for about $7.50 each at a local auto store or replace them with new for about $20 to as high as you want to spend. If you choose the new set, keep the old ones, have them resurfaced and ready for reinstallation should the new ones develop the same problem.

One of the contributing causes to warpage of the rotors on our cars is excessive lug nut torque. Make sure the nuts are torqued to the proper range of 80-105 lb-ft and not by an air gun.

 

[SHO_Driver]

You can rule out the outer tie rods, balljoints or other front end problem by checking for play in the front wheels. With the wheel off the ground check for any vertical or horizontal play of the wheel.

 

[Shoaz]

The very first thing to check is that all of your lug nuts are tight on the front wheels (well, all of them, actually). The only times I've had serious vibration under braking was becuase of loose lug nuts.

A second point: "warped" rotors is generally a misnomer, as the rotors are almost always still true geometrically. If anyone knows of a case where overheating caused a rotor to twist, please document it. Usually what ends up getting referred to as "warping" is uneven surface loading of the pad material onto the rotor face, which can happen if the pad and rotor are hot and you sit stopped with the brakes applied. Having the rotors turned removes the surface loading and takes it down to a fresh, even surface.

 

[David Mueller]

If you are getting "warped" rotors you might also consider replacing the calipers. I think a rebuilt set of calipers is like $12.50 or so on exchange.

 

[oh_SHO]

Where are you getting calipers for $12.50 exchanged? Wait or is it the rear ones that are pricey?

 

[David Mueller]

The rear one are pricey because they are unique to the SHO's, however the front ones are the same as all the other Tauri. I am getting that price from O'Rielly's Auto Parts.

 

[oh_SHO]

The rear one are pricey because they are unique to the SHO's, however the front ones are the same as all the other Tauri. I am getting that price from O'Rielly's Auto Parts.

I beg to differ. I've pulled ones from boneyards for a beater I used to have. The e-brake cables are the same too. Maybe they are pricey because SHOs have them and it was an option on SLOs?

 

[David Mueller]

The rear disk brake (and thus the calipers) may be an option on the non SHO taurus, but the point was, that they are not a heavy production item, hence the increased price.

 

[oh_SHO]

Ok point taken. I just thought that would be some useful info. I believe that early Lincs shared the 92 and lower rear caliper too...

 

[Best Sho]

Thanks all for the reply. I never had them 'air gunned'. I use a speed bar and never paid attention to the torque before. But I will now.

Thanks, Mike