Brake pedal fluttering

[Gossamer]

On my 2002 Tahoe I get this fluttering/pulsing feeling from my brake pedal. It doesn't do it all the time and some times it is worse than other times. Brakes seem to be working fine.
Could this be the anti lock brake sensors going bad?

Thanks for any suggestions.

 

[Big Mama]

Most likely but might just be a loose wire especially if there’s no dash lights on. Crawl under and look around

 

[watuzi]

Probably a bad/warped rotors. I had the same issue before. The trick is to find out which side is bad.

 

[Doubeleive]

could be the rotors need to be turned, or could be a bad wheel hub sensor one being slightly out of sync could possibly not throw a ABS code, generally if it is a wheel sensor you would get the pulsing in the pedal just before coming to a full stop, the pedal would be kind of kicking back at you and you would maybe hear the abs pump throwing a fit at the same time.

 

[Gossamer]

could be the rotors need to be turned, or could be a bad wheel hub sensor one being slightly out of sync could possibly not throw a ABS code, generally if it is a wheel sensor you would get the pulsing in the pedal just before coming to a full stop, the pedal would be kind of kicking back at you and you would maybe hear the abs pump throwing a fit at the same time.

The thing is, it's not consistent. I would think the rotors would be consistently the same.
Sometimes it is a very smooth stop, sometimes alittle pulsating, other times a lot of pulsating.
It's for sure the front because the steering wheel will shimmy when it does it.
Starting yesterday, the ABS/Brake light has come on, but then goes off.

 

[RST Dana]

The thing is, it's not consistent. I would think the rotors would be consistently the same.
Sometimes it is a very smooth stop, sometimes alittle pulsating, other times a lot of pulsating.
It's for sure the front because the steering wheel will shimmy when it does it.
Starting yesterday, the ABS/Brake light has come on, but then goes off.

Get the rotors hot and see if the issue is more pronounced. Several hard stops should do the trick. They are an easy upgrade.

 

[Gossamer]

Get the rotors hot and see if the issue is more pronounced. Several hard stops should do the trick. They are an easy upgrade.

It happens when they are cold and when the brakes are applied a lot and hot. I could travel down the road and come to a stop then travel another mile and it smoothly stops. No consistent behavior at all. Very random.

 

[Doubeleive]

It happens when they are cold and when the brakes are applied a lot and hot. I could travel down the road and come to a stop then travel another mile and it smoothly stops. No consistent behavior at all. Very random.

If you have a scanner or access to a scanner that does ABS there should be a historical code saved in the abs system even if the light is not currently on, since the abs light did come on and the pulsing is not consistent I would lean more towards a faulty sensor or possibly a failing wheel hub, what you can do without any special equipment is just jack up the front wheels or one wheel at a time and once it is off the ground grab the wheel at 12 & 6 and see if it has any play (wiggle there should be none) there will be slight play at 9 & 3 because of the steering, or if it makes any noise when you spin it (compare each side for noise). Even if the rotors were bad it still should not cause the abs light to come on.

 

[Gossamer]

If you have a scanner or access to a scanner that does ABS there should be a historical code saved in the abs system even if the light is not currently on, since the abs light did come on and the pulsing is not consistent I would lean more towards a faulty sensor or possibly a failing wheel hub, what you can do without any special equipment is just jack up the front wheels or one wheel at a time and once it is off the ground grab the wheel at 12 & 6 and see if it has any play (wiggle there should be none) there will be slight play at 9 & 3 because of the steering, or if it makes any noise when you spin it (compare each side for noise). Even if the rotors were bad it still should not cause the abs light to come on.

Ok, I will check that, thanks

 

[SnowDrifter]

Does it sound like your abs is kicking on? Or something else?

Speed sensitive?

 

[DirtyBlackHoe]

Were these year models hydroboost?

 

[SnowDrifter]

Were these year models hydroboost?

My 05 is. Not sure what years or what options had hydroboost

 

[grouch]

When a warp is minor, it will be worse when the brakes are hot. After a while the heat and cool cycle will make it worse. Eventually you will have it hammering your foot when you stop and sometimes the steering wheel will shake going down the road. When that happens, your braking is compromised.

 

[bottomline2000]

Were these year models hydroboost?

Hydroboost didnt start until 2004. I've had something similar happening to my truck. My brakes are all new (1 year ago)except my rear calipers. Going to make sure the rear calipers are not hanging up and bleeding the brakes. There may be air in the lines. I added hydroboost to my truck and the pedal was kinda flat with a dead spot until I flushed the system. Gonna run a gallon of fluid through and see how they feel.

 

[OneofFew]

Probably a bad/warped rotors. I had the same issue before. The trick is to find out which side is bad.

If it is a once per tire revolution thing, chances are it is one of your brakes. You may discover a cracked rotor.

 

[nofaz]

Have the same issue with my 13 Yukon. Soft braking makes the pedal flutter. Flutter slows as the vehicle does. I've replaced the front rotors twice in the last 6 months. The first time when I was doing a front brake job (it needed it!). The second time to try and stop the problem. I bought the HD GM rotors from a police package the second time but the problem did not change. It is intermittent, there are times when you can't feel a thing on the pedal. At the next stop light it feels like it wants to throw you out the window. Just about had enough and am going to take it to the dealer.

 

[Big Mama]

Have you looked at the rear brakes? If you take it in find a reputable indie you’ll usually get better, faster, cheaper repairs.

 

[retiredsparky]

There is also a specific way to bleed the abs pump/lines that a shop can do with a scan tool. If even a little air has gotten into the ABS, you can have symptoms like you are describing.

As others have said, a sensor or front axle unit bearing going out will also cause a problem. The intermittent and variable nature makes it seem more likely that a sensor is starting to fail.

 

[nofaz]

If there were a sensor failure would there not be a code showing up? I'd thought of a problem with the rear brakes but as I understand it the rear brakes don't have as much effect as the front.

 

[Fless]

Have the same issue with my 13 Yukon. Soft braking makes the pedal flutter. Flutter slows as the vehicle does. I've replaced the front rotors twice in the last 6 months. The first time when I was doing a front brake job (it needed it!). The second time to try and stop the problem. I bought the HD GM rotors from a police package the second time but the problem did not change. It is intermittent, there are times when you can't feel a thing on the pedal. At the next stop light it feels like it wants to throw you out the window. Just about had enough and am going to take it to the dealer.

Are the new pads being "bed" to the new rotors? Most pad mfrs have a specific procedure to be them in.