Pulsing pedal after brake work

[vincewarde]

Just finished a great deal of front end work on my 1993 4x4 (pads, rotors, axle shafts and ball joints). Prior to this work the brake pedal pulsed on brake application. I assumed that this was due to warped rotors (they were very bad). It is now evident that the problem lies elsewhere.

Now the pulsing pedal is much, much worse. The ABS light is on. I am confident that we did not damage the sensors while doing the work - but they are old. After reading some posts here I am convienced that the problem is the ABS. Is there any way to confirm this? How about figuring out what I need to replace?

Thanks in advance!

 

[rhauf]

define pulsating pedal.... rapidly vibrating, or one "pulse" per revolution of the tire?

if it's rapidly vibrating, then yes it's the abs.. but i suspect it's something in you're spindle, or rotor still. or maybe you didn't tighten you're wheel lugs evenly (did you tighten one hard before starting the others?)

try putting it up on jack stands and spin the tires by hand one at a time, see if one feels like it wants to stick at a certain point in its rotation, or if the brakes drag as it passes one point, etc. do that with the fronts as well as the rears. this may help lead you to the problem.

 

[vincewarde]

More info

The pulsing seems to be slow - as in 1-2 pulses per wheel rotation. Maybe 1/3 of the rotation is the "pulse". Wheel bearings were tightened per the instructions (I have done them before).

I'll check the other items you suggested.

 

[rhauf]

my guess is there is still something wrong with one of the rotors.

 

[Daniel77]

You said this pulsating was there before brake work . check back brakes .
If they need replaced or not adjusted correctly . This will put all your
braking on the front brakes (pulsating) .If all brakes are not grabbing
equal or there is air in brake line your Abs light will be on

 

[vincewarde]

Thanks to all who have posted.

I am disabled and I have to wait for lifting help before I can pull wheels or do anything requiring heavy lifting - but I was able to get the front wheels off the ground. The left wheel does seem to be dragging when manually rotated. As for the rear brakes, they surely need to be done (206,000 miles - never done as far as I know) - I will consider moving them up higher on the todo list. I tend to think they are not the problem since the issue got a lot worse after I replaced most of the front end parts.

BTW - I have converted to manual hubs. I don't see how that could be the problem, but thought I would mention it.

Thanks again for all your help!

 

[1AJeremyD]

206,000 miles and never done? Nearly impossible unless you're using the fins to stop the truck now. Sounds like the rotor is warped to me.

 

[vincewarde]

206,000 miles and never done? Nearly impossible unless you're using the fins to stop the truck now. Sounds like the rotor is warped to me.

I bought the truck at 119,000 and I have never done them. They may have been done by a previous owner. I think there is something left besides the fins

I too am thinking I got a bad rotor. I'll pull the caliper and see if the dragging stops.

 

[huntman58]

I know because I have done it you can warp a rotor from the get go by not putting the tire and rim on right. do not tighten one lug up hard then move on but do them just like a manifold do them a bit at a time up to the right torque so you do not warp the rotor . Most do not know about that and with cheaper rotors it’s even more important.

 

[1AJeremyD]

I know because I have done it you can warp a rotor from the get go by not putting the tire and rim on right. do not tighten one lug up hard then move on but do them just like a manifold do them a bit at a time up to the right torque so you do not warp the rotor . Most do not know about that and with cheaper rotors it’s even more important.

^^^^ completely agree with that. A misaligned wheel on the hub will throw the rotor off just enough for it to cause problems.

 

[vincewarde]

Problem fixed

Exchanged the drivers side rotor for a new (unwrapped). No more pulsing. Brand new rotor was wrapped. ABS light is still on, but that's another problem

 

[huntman58]

Glad to here ya got the warped rotor fixed.
I fought like heck on my ex with the same deal. Did full front brakes because of bad rotors. When done dang it was still doing it, so pulled it apart and checked the rotors and I be danged they were warped. Took them back got my money back and then bought some good ones some other place (read more expensive) now thousands of miles later still stops like new and smooth. Sold me also on cross drilled rotors!