Why do my brakes pulse again?
 

I have a 1997 Jeep Cherokee Laredo 4x4 with 36,000 miles on it. I do mostly
"around home" driving (not really city or highway driving).

My question is why my brakes 'pulse' once again. When braking, it feels
like there are high and low spots on the discs. I had them ground once
which fixed the problem but it's back yet again. I'm very easy on the
brakes. Someone said they may warp when hot and hitting a puddle but that
doesn't sound reasonable.

Any ideas as to why this keeps happening would be great. Thanks.

Re: Why do my brakes pulse again?
 

Ted S. wrote:
> I have a 1997 Jeep Cherokee Laredo 4x4 with 36,000 miles on it. I do mostly
> "around home" driving (not really city or highway driving).
>
> My question is why my brakes 'pulse' once again. When braking, it feels
> like there are high and low spots on the discs. I had them ground once
> which fixed the problem but it's back yet again. I'm very easy on the
> brakes. Someone said they may warp when hot and hitting a puddle but that
> doesn't sound reasonable.
>
> Any ideas as to why this keeps happening would be great. Thanks.
>
>

Several things can cause rotor warping or nonuniform thickness:

1. Overheating from severe use (long hills, towing, etc.)
2. Marginally designed rotors (most vehicles today unfortunately)
3. Overtorqued lug nuts
4. Rust from lack of use
5. Probably several more that I'm not aware of!

I think overtorqued lug nuts are one of the most preventable causes, at
least next to avoiding severe use. Rotors are more likely to warp a
second time after being turned. There is now less metal to absorb heat
and less metal to resist the stresses induced by the heat. I think on
most new cars and many trucks, it is a waste of time to turn the rotors.
Better to just replace them, and the cost delta isn't all that great
anyway.

Matt

Re: Why do my brakes pulse again?
 

Ted S. wrote:

> I have a 1997 Jeep Cherokee Laredo 4x4 with 36,000 miles on it. I do mostly
> "around home" driving (not really city or highway driving).
>
> My question is why my brakes 'pulse' once again. When braking, it feels
> like there are high and low spots on the discs. I had them ground once
> which fixed the problem but it's back yet again. I'm very easy on the
> brakes. Someone said they may warp when hot and hitting a puddle but that
> doesn't sound reasonable.
>
> Any ideas as to why this keeps happening would be great. Thanks.

Prior to any of the events, had anyone rotated or removed and
replaced any tires? This can cause the rotors to warp. Once
that happens, just replace them with an aftermarket set of
your choice. Turning them takes away metal which make them
more susceptible to warping in the future.

Re: Why do my brakes pulse again?
 

"Matthew S. Whiting" <whiting@epix.net> wrote in message
news:3F21C61E.2020607@epix.net...
> Several things can cause rotor warping or nonuniform thickness:
>
> 1. Overheating from severe use (long hills, towing, etc.)
> 2. Marginally designed rotors (most vehicles today unfortunately)
> 3. Overtorqued lug nuts
> 4. Rust from lack of use
> 5. Probably several more that I'm not aware of!
>
> I think overtorqued lug nuts are one of the most preventable causes, at
> least next to avoiding severe use. Rotors are more likely to warp a
> second time after being turned. There is now less metal to absorb heat
> and less metal to resist the stresses induced by the heat. I think on
> most new cars and many trucks, it is a waste of time to turn the rotors.
> Better to just replace them, and the cost delta isn't all that great
> anyway.
>
> Matt
>

Yep, #3 is the one I'd bet on. Usually by over zealous use of the air
wrench by the place that rotates your tires.

PC

Re: Why do my brakes pulse again?
 

What does rotating tires have to do with warping rotors?

I think it's over tightened lugs.


"Lon Stowell" <lon.stowell@comcast.net> wrote in message
news:E1adnXXHSITxSbyiXTWJig@comcast.com...
> Ted S. wrote:
>
> > I have a 1997 Jeep Cherokee Laredo 4x4 with 36,000 miles on it. I do
mostly
> > "around home" driving (not really city or highway driving).
> >
> > My question is why my brakes 'pulse' once again. When braking, it feels
> > like there are high and low spots on the discs. I had them ground once
> > which fixed the problem but it's back yet again. I'm very easy on the
> > brakes. Someone said they may warp when hot and hitting a puddle but
that
> > doesn't sound reasonable.
> >
> > Any ideas as to why this keeps happening would be great. Thanks.
>
> Prior to any of the events, had anyone rotated or removed and
> replaced any tires? This can cause the rotors to warp. Once
> that happens, just replace them with an aftermarket set of
> your choice. Turning them takes away metal which make them
> more susceptible to warping in the future.
>
>

Re: Why do my brakes pulse again?
 

Hi,
If someone used a impact gun while tighten your lug nuts.It has
enough power to over tighten the rim to the rotor.Which can cause the
rotor to warp.
When you apply the brake-you will feel a pulsating pedal.Feels like
something is pushing up from under the brake pedal.
That is why a tork wrench or tork stick is used to reinstall a
tire.This way it is not over tightened.
I hope this info. helps you.
Good luck.


On Sat, 26 Jul 2003 09:39:32 GMT, "Desert YJ"
<jeepaholics@earthlink.net> wrote:

>What does rotating tires have to do with warping rotors?
>
>I think it's over tightened lugs.
>
>
>"Lon Stowell" <lon.stowell@comcast.net> wrote in message
>news:E1adnXXHSITxSbyiXTWJig@comcast.com...
>> Ted S. wrote:
>>
>> > I have a 1997 Jeep Cherokee Laredo 4x4 with 36,000 miles on it. I do
>mostly
>> > "around home" driving (not really city or highway driving).
>> >
>> > My question is why my brakes 'pulse' once again. When braking, it feels
>> > like there are high and low spots on the discs. I had them ground once
>> > which fixed the problem but it's back yet again. I'm very easy on the
>> > brakes. Someone said they may warp when hot and hitting a puddle but
>that
>> > doesn't sound reasonable.
>> >
>> > Any ideas as to why this keeps happening would be great. Thanks.
>>
>> Prior to any of the events, had anyone rotated or removed and
>> replaced any tires? This can cause the rotors to warp. Once
>> that happens, just replace them with an aftermarket set of
>> your choice. Turning them takes away metal which make them
>> more susceptible to warping in the future.
>>
>>
>

Have sence,patience,and self-restrain,and no mischief will come.

Re: Why do my brakes pulse again?
 

"Ted S." <tswirsky@screaminet.com> wrote in message
news:bfscbr031cu@enews1.newsguy.com...
> I have a 1997 Jeep Cherokee Laredo 4x4 with 36,000 miles on it. I do
mostly
> "around home" driving (not really city or highway driving).
>
> My question is why my brakes 'pulse' once again. When braking, it feels
> like there are high and low spots on the discs. I had them ground once
> which fixed the problem but it's back yet again. I'm very easy on the
> brakes. Someone said they may warp when hot and hitting a puddle but that
> doesn't sound reasonable.
>

Having warped disk rotors ground, or "turned" is a good short-term fix. The
problem is, however, that the more they are turned, the thinner they become.
The thinner they become, the more susceptible they become to warpage. So it
is a vicious circle kind of thing.

You probably need to have the rotors replaced. But if they wore out at only
36K miles, something ain't right. Maybe they can be replaced under
warranty.

-Cyberbilly

Re: Why do my brakes pulse again?
 

The simple answer is Chrysler rotors are JUNK. My '96 Stratus rotors were
doing the same thing at 15,000 miles. Chrysler replaced them, but said that
the warranty on "wear parts" was only 12,000 miles. I had the same problem
with them at around 25,000 miles. I replaced those with the cheap NAPA ones
in the green box and they were on the car until I traded it in at 186,000
miles. They were $16 each.

I bought a new Sebring convertible about three months ago. I have 9,000
miles on the car and the brakes are pulsating already. It has 4 wheel
disks, so I'm bringing it in next week to see what they are going to do
about it.


"Ted S." <tswirsky@screaminet.com> wrote in message
news:bfscbr031cu@enews1.newsguy.com...
> I have a 1997 Jeep Cherokee Laredo 4x4 with 36,000 miles on it. I do
mostly
> "around home" driving (not really city or highway driving).
>
> My question is why my brakes 'pulse' once again. When braking, it feels
> like there are high and low spots on the discs. I had them ground once
> which fixed the problem but it's back yet again. I'm very easy on the
> brakes. Someone said they may warp when hot and hitting a puddle but that
> doesn't sound reasonable.
>
> Any ideas as to why this keeps happening would be great. Thanks.
>
>

Re: Why do my brakes pulse again?
 

the xj rotors are a composit metal and warp real easy once they have be
resurfaced
the rotors don't take well to heat up after that so i would recommend new ones

"Ted S." wrote:

> I have a 1997 Jeep Cherokee Laredo 4x4 with 36,000 miles on it. I do mostly
> "around home" driving (not really city or highway driving).
>
> My question is why my brakes 'pulse' once again. When braking, it feels
> like there are high and low spots on the discs. I had them ground once
> which fixed the problem but it's back yet again. I'm very easy on the
> brakes. Someone said they may warp when hot and hitting a puddle but that
> doesn't sound reasonable.
>
> Any ideas as to why this keeps happening would be great. Thanks.

Re: Why do my brakes pulse again?
 

Oh.


"Lon Stowell" <lon.stowell@comcast.net> wrote in message
news:rk6dnRm1KJPxar-iXTWJiw@comcast.com...
> You have some way to rotate tires without taking the lug nuts
> off and putting them back? Care to share?
>
>
> Desert YJ wrote:
>
> > What does rotating tires have to do with warping rotors?
> >
> > I think it's over tightened lugs.
> >
> >
> > "Lon Stowell" <lon.stowell@comcast.net> wrote in message
> > news:E1adnXXHSITxSbyiXTWJig@comcast.com...
> >> Ted S. wrote:
> >>
> >> > I have a 1997 Jeep Cherokee Laredo 4x4 with 36,000 miles on it. I do
> > mostly
> >> > "around home" driving (not really city or highway driving).
> >> >
> >> > My question is why my brakes 'pulse' once again. When braking, it
feels
> >> > like there are high and low spots on the discs. I had them ground
once
> >> > which fixed the problem but it's back yet again. I'm very easy on
the
> >> > brakes. Someone said they may warp when hot and hitting a puddle but
> > that
> >> > doesn't sound reasonable.
> >> >
> >> > Any ideas as to why this keeps happening would be great. Thanks.
> >>
> >> Prior to any of the events, had anyone rotated or removed and
> >> replaced any tires? This can cause the rotors to warp. Once
> >> that happens, just replace them with an aftermarket set of
> >> your choice. Turning them takes away metal which make them
> >> more susceptible to warping in the future.
> >>
> >>
> >
> >
>