Brake Pulsing/Surging problem

[mooker82]

My 97 has recently develop a low speed braking problem. When slowing down completely it feels as if the brakes are pulsing. It feels like the brakes are catching then uncatching every second. It only does this from 15-20 MPH. The rotors are not warped and the pads are still in good condition. I have an OME lift and have adjusted the LSPV, however Im not sure if its adjusted enough. Could this cause my problem? Any other ideas?

 

[RavenTai]

sounds like you have some pad material stuck on one or more of the rotors happens when the brakes get overly hot and you sit in one spot (such as sitting at a light after heavy braking) mine had this at one time, pad/rotor wear took care of it,

Warped rotors give a similar but slightly different feel more a shimmy or vibration.

 

[mooker82]

Theres no shimmy or vibration. Its been doing this for 2 days. If it were pad material sticking should it be gone now?

 

[RavenTai]

IIRC mine did it for a wile, I do not brake much though.

 

[CJF]

Supposedly, doing this can help:

http://www.zeckhausen.com/bedding_in_brakes.htm

Let us know if you try it,

Curtis

 

[zipastro]

Mine does this also, even after new rotors. I think the culprit is actualy the rear rotors, have you checked them?

 

[mooker82]

The rear rotors were still thick and the pads were good. I do not believe that they are warped. Im going to get the runout on them checked though. It just feels like the front brakes are catching.

 

[cheap 40]

Had the same thing happen on my 97 and on my Honda. A re-bed solved both problems.

Tony

 

[concretejungle]

Mine just started doing the same thing. I was going to take the wheels off and buff the rotors with a scotchbrite pad or something similar to clean the surface of any brake pad material accumulation.

 

[mooker82]

Any particular kind to use? Certain type of sand paper? Grit? Ive heard something about using a special type but cant recall it or find the info anywhere.

 

[CJF]

C'mon guys: Try re-bedding them; get some data for us!

Curtis

 

[mooker82]

Im going to give it a shot when I get off work tonight. There is too much traffic right now for me to speed up and slam on the brakes repeatedly.

 

[CJF]

Cool. Be careful!

 

[concretejungle]

I will "re-bed" them after i polish them. I just want to do it that way.

As for the grit on the pad, i picked up some synthetic material scotchbrite pad from lowes. It's similar to steel wool, but it's not steel.

 

[syrinxstar]

loose front wheel bearings will cause similar problems. Have you tried rocking the wheel at the 12-6 o' clock positions when it's jacked?

 

[mooker82]

Didnt even think about that. Just tried it and the left front rocks a tad bit and the right side does not. The front end was done by the dealer when I bought it. Can I just remove the lock washer and lock nut, retorque the adjusting nut then check the preload?

 

[fzj80kidpen]

Mine did the samething.
When I rebuilt the front axle I had a set of rotors and was planning on changing them but they looked fine.
I ended up just replacing the brake pads all around, bled the old fluid off and was generous with the brake cleaner on all rotor surfaces.
When it was all put back together the pulsing was gone.
Now 25k miles later its coming back slowly.
Time to rebleed, front pad, reclean again

 

[syrinxstar]

Yep, it's pretty quick to get it tightened down again. Getting the cone washers off always takes me the longest. I need to get a brass hammer.

 

[mooker82]

Thanks. I will give it a shot tommorow. My boss hates it when I am greasy and late to work because of my truck.