99 WS-sick

iTrader: (2)

i have a 99 T/A, at speeds above 80mph in a straight line the brakes pulsate (not pedal), just the brakes, the car pulls side to side. if im going into a turn and i hit the brakes to hard the car pulls side to side. if i hit the brakes going over dumps the "lowtrac" light comes on but im not sliding or locking up the tires. and when i slowly come to a stop, SOMETIMES not all the time, the car will pull to one side (its not always the same side). i can feel the pedal get stiff and then it feels like it releases some presure and everything goes normal again but it only does that if im standing on the brakes (feels like im gonna break the pedal). i have 17inch wheels in the front and 18inch wheels in the back but the outside diameter is basicly the same. its worse between 120-150 mph. im thinking its the abs but im not sure, the calipers have been changed and the rotars are not warped. any advice will help

99 WS-sick

iTrader: (2)

has nobody ever had this problem??

wrencher

iTrader: (2)

Basic's are the slides OK free & lubed?
Still sounds like the rotors are warped. If it shakes the wheel they're warped.
The low trac light may be a result of pulling under braking maybe, possibly a wheel speed sensor falling off too.
need to figure out what makes it pull & wag under braking, front end componets making it wander etc....
You have multiple issues going on here, but like i said start with the basic's & work your way back.

99 WS-sick

iTrader: (2)

i know its not the rotors, the car does follow any road variation. best way to discribe this is- when driving over a raod that is heavliy travled by "big rigs" the road has ruts in it, the steering wheel and car movs with the contor of the road. its hard to explain but thats the best i can do.

wssix99

iTrader: (5)

I'd think that a brake problem (like a difference in clamping force) would cause you to consistently go to one side.

I wonder how your front end is doing? I'd also check the hubs, ball joints, and steering linkages. Maybe you have a loose component in the steering?

You should check the hubs first by raising each front wheel, grabbing the wheel at 3 o'clock and 9 o'clock, then pulling side to side. If you have any wobble, the hub is bad and the car is not safe to drive.

99 WS-sick

iTrader: (2)

i didnt even think about the ball joints but why would the pedal stiffness change during braking and turning and braking? it feels exactly like the abs is activating but my lights dont come on and the brakes arent even close to locking up.

wssix99

iTrader: (5)

If your wheels are flopping around, that may push back on the brakes and give you feel of it in the pedal. If you feel pulsation and don't have the low trac light then the low trac light bulb is out or you have a wicked vibration - not the ABS.

timespayne

Front end alignment and bleed brake system before you start to throw big money IMO, but thats where I would start.

wrencher

iTrader: (2)

Very common complaint with F-cars & normal.
Only thing you can do is have the alignment & suspension in order.
But they will always follow ruts, just the way they are.
Like I said sounds like you have multiple issues....
Alignment, brakes etc.

wssix99

iTrader: (5)

And this gets worse with larger tires, etc.

While a lot of of this sounds typical, a loose suspension piece can make the whole thing worse. The pulsation/vibration is also not a good thing.

99 WS-sick

iTrader: (2)

im trying to figure out where to start, its not the ball joints (checked), its not the rotors/calipers(checked), the alignment is just slightly off. ill have my alignment guy check it out next week and see if everything is good under the front, ill keep ya posted

wssix99

iTrader: (5)

What about your hubs and the steering rack?

99 WS-sick

iTrader: (2)

the hubs are also good, the R&P also came to my mind but i dont see how that could effect that brakes. im gonna bleed the intire system next week, im thinking its the abs module

wssix99

iTrader: (5)

Right - but you said the brakes were good. (Just activating the brakes can expose suspension problems.)

When the ABS goes off, you should get a Low Trac light. Also, a malfunctioning ABS system will throw codes. You may have your car scanned by someone who can pull the ABS codes. (A regular scanner will not do this.)

99 WS-sick

iTrader: (2)

wat do u mean activating the brakes can cause a suspesion problem?

wssix99

iTrader: (5)

Braking (particularly braking and turning at the same time) puts different kinds of forces on the suspension vs. when you are driving normally. So, if a suspension part is broken, it may only be exposed when you are braking and seem "normal" when you are driving forward.

For example, I had some bad hubs a while back. Driving normally they were fine, but they squealed horribly when I was under braking.

99 WS-sick

iTrader: (2)

ok so it could posibly be tie rod or rack an pinion problem?

wssix99

iTrader: (5)

Sure. Another thing to do is have a buddy drive by either side of your car on a wide street while you brake and recreate the problem. If there is a suspension issue, they may be able to see a wobble. They may also be able to hear any noises produced better than you can in the car.

barkerracing59

I have this problem too with my brakes the rotors are warped but if I stand on the pedal it goes hard then quickly soft like the abs kicked in and the pedal is hard again. I have z06 c5 brakes so don't know what's going on. And I know its not the pads getting pushed back because I race bikes on road courses so I always pump the pedal quick to make sure I have brakes. So I think my brakes are too stiff and making the abs think the wheels are locked and there no where need locked

99 WS-sick

iTrader: (2)

thats wat im experiencing, the pedal has the feel of the abs activting, the pedal gets firm and soft, its a feeling of fluid presure escaping somewhere. example- if u fill a ballon with a little bit of water, then pinch the balloon in the middle, sqeeze the water/air pocket, the water quickly "squezes" through the pinched area of the ballon. this is sort of the feeling im experiencing, nobody has ever heard of this exact senario that iv talked to. im gonna start with the suspension then move forward from there.