brakes throbbing - how to proceed?

'04 Cavalier. Considerable pulsing in the pedal when the brakes are
applied. The pulsing is speed-dependent - I think it's probably one
throb per wheel revolution. There's no significant shaking of the
steering wheel. Stopping seems unimpaired. There may be some
variability in the pulsing: it may be worse after coming off a short run
at higher speed. (That is not certain, though.)

What I've done so far:
- Changed the (front) pads. Outer pads had more wear. Calipers
now moves freely.
- Replaced one rotor. Inside plating was deteriorated.
- Replaced one hub assembly. (see (1) below.)
- Replaced the other hub assembly last fall, to fix a noise.

Things I can do next:

- replace the other rotor. My gut says, this won't help.
Sometimes, my gut is wrong.
- look at the rear (drum) brakes. The rears on this car are
mostly cosmetic, IMO. Not to mention, Getting the drums off
is a PITA.
- get the balance checked on the wheels.

Or something else?

Any thoughts/experience appreciated.

G

(1) re hub assembly replacement: When I ran the car (low gear) with one
control arm jacked up, wheel removed, lug nuts snug on the rotor, wobble
was visible in the rotor. It was pushing against the brake pads, and I
thought for sure this was the problem. No joy.

"George" > wrote in message
...
> '04 Cavalier. Considerable pulsing in the pedal when the brakes are
> applied.

As you probably already know, this is almost always due to rotors,
and can be (1) warp, (2)out of parallel rotor faces, or (3)rotors
installed with dirt or rust between them and the hub.

There could be other contributing factors

On 04/10/2011 08:02 AM, George wrote:
> '04 Cavalier. Considerable pulsing in the pedal when the brakes are
> applied. The pulsing is speed-dependent - I think it's probably one
> throb per wheel revolution. There's no significant shaking of the
> steering wheel. Stopping seems unimpaired. There may be some
> variability in the pulsing: it may be worse after coming off a short run
> at higher speed. (That is not certain, though.)
>
> What I've done so far:
> - Changed the (front) pads. Outer pads had more wear. Calipers
> now moves freely.
> - Replaced one rotor. Inside plating was deteriorated.
> - Replaced one hub assembly. (see (1) below.)
> - Replaced the other hub assembly last fall, to fix a noise.
>
> Things I can do next:
>
> - replace the other rotor. My gut says, this won't help.
> Sometimes, my gut is wrong.

yeah.

there's nothing "gut" about brakes. it's all about understanding what
goes on, observing the situation that exists, then using both sets of
data to figure out the result. real simple.


> - look at the rear (drum) brakes. The rears on this car are
> mostly cosmetic, IMO. Not to mention, Getting the drums off
> is a PITA.
> - get the balance checked on the wheels.
>
> Or something else?
>
> Any thoughts/experience appreciated.
>
> G
>
> (1) re hub assembly replacement: When I ran the car (low gear) with one
> control arm jacked up, wheel removed, lug nuts snug on the rotor, wobble
> was visible in the rotor. It was pushing against the brake pads, and I
> thought for sure this was the problem. No joy.

george, you posted about this march 18th. try re-reading the thread and
acting accordingly - all the answers to your questions are in there.

either that or just cough up the money to have a professional take care
of it.


--
nomina rutrum rutrum

On 04/10/2011 08:22 AM, hls wrote:
>
> "George" > wrote in message
> ...
>> '04 Cavalier. Considerable pulsing in the pedal when the brakes are
>> applied.
>
> As you probably already know, this is almost always due to rotors,
> and can be (1) warp,

very unlikely. we've discussed this before.


> (2)out of parallel rotor faces,

how do you think that's possible? you think that a brake pad can
somehow index then abrade a disk in just one arc sector and not others?


> or (3)rotors
> installed with dirt or rust between them and the hub.

how do you install rust?


>
> There could be other contributing factors

yeah. but none as likely and the propagating of myth without bothering
to consider or learn the facts.


--
nomina rutrum rutrum

On Apr 10, 11:02*am, George > wrote:
> '04 Cavalier. *Considerable pulsing in the pedal when the brakes are
> applied. *The pulsing is speed-dependent - I think it's probably one
> throb per wheel revolution. *There's no significant shaking of the
> steering wheel. *Stopping seems unimpaired. *There may be some
> variability in the pulsing: it may be worse after coming off a short run
> at higher speed. *(That is not certain, though.)
>
> What I've done so far:
> - Changed the (front) pads. *Outer pads had more wear. *Calipers
> * now moves freely.
> - Replaced one rotor. *Inside plating was deteriorated.
> - Replaced one hub assembly. *(see (1) below.)
> - Replaced the other hub assembly last fall, to fix a noise.
>
> Things I can do next:
>
> - replace the other rotor. *My gut says, this won't help. *
> * Sometimes, my gut is wrong.
> - look at the rear (drum) brakes. *The rears on this car are
> * mostly cosmetic, IMO. *Not to mention, Getting the drums off
> * is a PITA.
> - get the balance checked on the wheels.
>
> Or something else?
>
> Any thoughts/experience appreciated.
>
> G
>
> (1) re hub assembly replacement: When I ran the car (low gear) with one
> control arm jacked up, wheel removed, lug nuts snug on the rotor, wobble
> was visible in the rotor. It was pushing against the brake pads, and I
> thought for sure this was the problem. *No joy.

Replace the other rotor. They should always be replaced in pairs
anyway, and also the likely cause of your pedal pulsation is rotor
runout.

Make sure the the caliper sliders are well lubed.

Reinstall wheels by hand, with a torque wrench. (inconsistent torque
can cause the rotors to warp slightly... really!)

If you still have pulsation, you may need to replace or turn the rear
rotors also.

Oh, and if the pedal pulsation bothers you, never NEVER buy a Chevy
Impala, it's the only vehicle I've owned that is showing signs of
warped rotors less than 1K miles after a full brake job (pads/rotors
all around.) What a POS.

nate

On Apr 10, 1:12*pm, N8N > wrote:
> On Apr 10, 11:02*am, George > wrote:
>
>
>
>
>
> > '04 Cavalier. *Considerable pulsing in the pedal when the brakes are
> > applied. *The pulsing is speed-dependent - I think it's probably one
> > throb per wheel revolution. *There's no significant shaking of the
> > steering wheel. *Stopping seems unimpaired. *There may be some
> > variability in the pulsing: it may be worse after coming off a short run
> > at higher speed. *(That is not certain, though.)
>
> > What I've done so far:
> > - Changed the (front) pads. *Outer pads had more wear. *Calipers
> > * now moves freely.
> > - Replaced one rotor. *Inside plating was deteriorated.
> > - Replaced one hub assembly. *(see (1) below.)
> > - Replaced the other hub assembly last fall, to fix a noise.
>
> > Things I can do next:
>
> > - replace the other rotor. *My gut says, this won't help. *
> > * Sometimes, my gut is wrong.
> > - look at the rear (drum) brakes. *The rears on this car are
> > * mostly cosmetic, IMO. *Not to mention, Getting the drums off
> > * is a PITA.
> > - get the balance checked on the wheels.
>
> > Or something else?
>
> > Any thoughts/experience appreciated.
>
> > G
>
> > (1) re hub assembly replacement: When I ran the car (low gear) with one
> > control arm jacked up, wheel removed, lug nuts snug on the rotor, wobble
> > was visible in the rotor. It was pushing against the brake pads, and I
> > thought for sure this was the problem. *No joy.
>
> Replace the other rotor. *They should always be replaced in pairs
> anyway, and also the likely cause of your pedal pulsation is rotor
> runout.
>
> Make sure the the caliper sliders are well lubed.
>
> Reinstall wheels by hand, with a torque wrench. *(inconsistent torque
> can cause the rotors to warp slightly... really!)
>
> If you still have pulsation, you may need to replace or turn the rear
> rotors also.
>
> Oh, and if the pedal pulsation bothers you, never NEVER buy a Chevy
> Impala, it's the only vehicle I've owned that is showing signs of
> warped rotors less than 1K miles after a full brake job (pads/rotors
> all around.) *What a POS.
>
> nate
As I have found out, replacing brakes on the cavalier is common.
Remember to keep the rears adjusted, wil lengthen life of fronts.

Greg

If was the (2nd) rotor. Thanks to all, apologies to any who feel they
need them.

"George" > wrote in message
...
> If was the (2nd) rotor. Thanks to all, apologies to any who feel they
> need them.

I dont think anyone needs apologies.. We all told you basically the same
thing and you have resolved the problem.

Congrat!!

On 04/21/2011 04:21 PM, hls wrote:
>
> "George" > wrote in message
> ...
>> If was the (2nd) rotor. Thanks to all, apologies to any who feel they
>> need them.
>
> I dont think anyone needs apologies.. We all told you basically the same
> thing

"we"??? i hope you're not trying to include your own divergent myth
propagation in that statement. unless you have delusions of royalty of
course.


> and you have resolved the problem.
>
> Congrat!!


--
nomina rutrum rutrum

jim beam wrote:
>
> On 04/21/2011 04:21 PM, hls wrote:
> >
> > "George" > wrote in message
> > ...
> >> If was the (2nd) rotor. Thanks to all, apologies to any who feel they
> >> need them.
> >
> > I dont think anyone needs apologies.. We all told you basically the same
> > thing
>
> "we"??? i hope you're not trying to include your own divergent myth
> propagation in that statement. unless you have delusions of royalty of
> course.
>

Well we know the "we" didn't include you since you offered no solution.