comming to a stop, pedal pulses??

[crash89]

Hey guys, this has been kinda going on for a while in the car but it hasnt really been a priority. But now its just getting annoying. When Im braking from higher speeds (anything over 25) the pedal feels fine until maybe the last 10-15 feet of stopping, then the pedal pulses.. There was a groove in my drives side rotor and I thought maybe that could be causing the problem. Recently I had my passenger side caliper hang up so I went to the local junk yard and picked me up a caliper and a set or rotors for 40 bucks.. Got them changed hoping that would fix the pulse in the pedal also, because I never got around to fixing that problem.. But noooo.... Still there. My buddy thinks maybe the brake booster could be going?? Im not to sure, never really dealt with brakes all that much except the usual pad/rotor/ and occasional caliper change. I know the brakes arent warped, there wasnt even a lip on them when I bought em. Anyone got any other ideas to look at? Thanks in advance.

 

[96eclipzGsT]

Rotors make the pedal pulse get new ones or take them to a parts store to see if they can be turned. Usually 5-10 bucks a rotor if they can turn them.

 

[95talongirl]

get some new rotors, as least. Remember that if you get used rotors, (or re-use then with new pads) the rotors was worn to the old pads, thus the surfaces are uneven, which can cause noise, pulsing and such. OR if they get to hot and warp, you'll get pulsing. I'd probably buy new pads and rotors at this point.

On a side note, my car had a terrible problem with the pulsation.. it did it after the first application of the brakes on brand new pads and rotors. I replaced the caliper brackets the second time around... with another set of pads and rotors... haven't had a problem since.

 

[shadoof77]

I had the same problem with my saturn way back when, the front disk rotors had like groves all along the inside of the rotor, and everytime i went to stop my car would shake the car. but got new rotors and it was all fixed. Also, my friends gsx did the same thing wasn't as bad, but he got some new rotors for all 4 tires and hasn't had any problems. So, like everyone else said check those rotors even if they have a small groove on the rotor you'll get a shake/pulse feel. Hope that helps.

 

[GRAVEDIGGER]

Pedal pulsation = bad/warped rotors

 

[KGB Pilot125]

Call around and find a shop that can do "On car machining" This is by far a better way to machine them than taking them off, especially since your already experiencing pulsations. One thing to remember though is that the warp in the rotor is likely to come back so change up your driving style and start saving for new rotors.
By the way we charge 45 bucks to on car machine rotors, lot cheaper than new rotors.
Josh

 

[crash89]

Like I said though, the rotors arent warped. And if they were Id feel the pulsation everytime I stop or apply the brakes. I only feel it in the last 20ish feet of comming to a stop, when Im going less then 15-20 mph. Never any other time. Thanks for the quick responses though!

 

[agedog2gT]

i would definitly check the rotors, they might be warped. i had a similar problem. i had the rotors flipped, resurfased and everything. Got new ones and the problem was all sovled. let me know what you come to. good luck!

 

[Fabian]

Like I said though, the rotors arent warped. And if they were Id feel the pulsation everytime I stop or apply the brakes. I only feel it in the last 20ish feet of comming to a stop, when Im going less then 15-20 mph. Never any other time. Thanks for the quick responses though!

I had a problem like this on a subaru that came into my shop a couple weeks ago. When you'd hit the brakes at like 40mph it wouldn't do a thing but slow down the way you'd expect, but in the last couple of feet you'd hear and feel the ABS system kicking in. Turned out to be that the ABS ring on the end of the axle was causing the disturbance. I'd check that out if you have an ABS equipped car. I'm more than willing to bet that's what it is.

 

[1g_TaLoN]

Also check your front wheel bearings. They will eat up front rotors as well.

 

[joegamma1]

I would say it's an ABS problem as well.

 

[95redturboawd]

The pedal pulsations from warped rotors aren't as noticeable if you're going fast enough. Have you checked the rear rotors too?

 

[warranty]

Another possibility for your brake pulsation (other than warped rotors) is uneven deposit (bed in) of brake pad material on the rotor, which causes uneven friction that probably becomes more noticeable as you slow down. I know this is probably a "controversial" topic, but it is a possible cause.

If you are not getting new rotors and you have a decent pad, what you may also consider is (1) turn the rotors so you have "fresh" surface to bed in the brake pads, and/or (2) bed in the brake pads again.

Bedding in brake pads basically involves a couple of consecutive, complete high-speed stops (from 60 to 0mph), then allow the brake rotors to cool down completely. This is something one is supposed to do anyway after installing new brake pads.

 

[ramsack]

does your car have ABS? if so check to see that there are no leaks in the brake system, especially around the ABS unit. next i would jack the car up and check to see if there is play in the wheel bearings, and check to see if the ABS sensors are good anymore. if you don't have ABS then the only thing would be warped rotors.

 

[1g_TaLoN]

Turning the rotors would cut the possibilities in half.

 

[ramsack]

warped rotors tend to shake things at higher speeds. at lower speeds they will most likely just make the car feel like you are pumping the brakes to stop. my ABS unit was leaking and causing the ABS to kick in no matter what. also my wheel bearings were bad.

 

[crash89]

Hey guys, thanks again for the quick responses. I wouldnt have even thought that the ABS would do this. Ill check that out when I get back to my car. Im currently 2000 miles away from it :/. Also I thought about the rear rotors after I posted my second post. I will deffinately check both suggestions out as soon as I can.