blkstealthpaid4

My pedal has been pulsating whenever I hit the brake pedal and at high speeds the front seat even shakes.This only happens when I hit the brake pedal.I went ahead and resurfaced some used rotors I had in the garage and changed them out with some new pads.Still the same problem.I have now changed the pads and rotors with new ones I got from NAPA and this problem is still there.This is my 1995 LS 400.I know my lower ball joints are weak but what else could cause this problem.The caliper has 4 pistons inside and could only 2 pistons expand and retract to cause this problem?I am clueless.The shaking feels like a serious rotor problem when I hit the brakes.

skperformance

iTrader: (6)

Did you lube the pistons before reinserting them?
If not they are seizing.

blkstealthpaid4

I never knew I had to lube the pistons at all.Has anyone ever had their pistons sieze and cause the brake pedal to go up and down when they applied the brakes?

ihatecarz

Sounds like the new rotors have too much run out-are warped. What brand rotors are they? Made in China? Take them back to NAPA and have them put them on their brake lathe and true them up. Also, be sure there is no crap, or excessive rust between rotors and hubs.

blkstealthpaid4

I really don't think the rotors are the culprit.I had a passenger in the back today who said the same thing.I have recut two different rotors and changed the pads twice.The third time was those brand new NAPA rotors and half ceramic pads.I am sure the culprit is either the tie rod,wheel hub or the weak balljoints(only on one side.)My uncle will find out tomorrow.I have spent 250 bucks in playing the guessing game.

cation

On top of replacing your lower ball joints that you say are bad, you should also look at your strut rod bushings. They can also cause the car to vibrate/pulsate/shake when you apply the brakes.

I have this issue to a small degree on my 93, but to replace them it will cost me about $250 doing it myself. I wish I had a 95' up since it would only cost about $100 doing it myself. The 95+ LS400s have a different more rudementary strut rod bushing design.

blkstealthpaid4

I did replace the strut rod 6 months ago with some junkyard ones and the symptoms where the normal sound when I went over speed bumps and also a thump when I stab the brakes at around 3-5 mph.After I changed them out with the junk yard ones, those symptoms went away and so I will rule those out too.The brake pulsating (up and down) was even there before I replaced the strut rod.I know I have a complicated issue that may seem obvious.

atoyot

never ever heard of that before

Well, not trying to be "that guy" but first you should have used OEM pads and rotors. At least rotors.

Secondly, did you seat the new pads? It is important to seat them in. It is a little more than a series of stops to heat them up, but it allows the pads and rotor surface to "jive" and not build up pad material on the rotor which leads to the pulsing.

damon

Any chance that you have damaged or have a non working ABS sensor?

Is the ABS system being activated when you brake?

blkstealthpaid4

The pads on the 95 are held by two tiny rods which is locked in by a much skinnier cotter pin looking rods and so there is no need to either put it in wrong or seat them in wrong.
1.The problem started when I completely changed the spindle(hub,rotor,ball joints all attached on right and left).
2.I installed all these already-attached pieces on both sides.Remind you that my oringinal rotors came off and the whole spindle got replaced with one from the yard.
The shaking then started.
3.I then changed lower ball joints on the right side (new) but I could not change the balljoints on the drivers side because I rounded the nuts on the ball joints with the impact wrench.At this time, the drivers side lower ball joint was weak.
4.When the shaking started , I took off the rotors twice and had them cut/resurface and also replaced the pads.The shaking is still there.
5.I changed the strut rod, and the thumping while going over bumps stopped, and the brake pedal pulsating/shaking was still there.
6.I then went ahead and bought new rotors from NAPA auto parts with new half ceramic pads(soft brake pads that will not eat up rotors) and changed them.The shaking was still there.
I have done nothing since.I had this same symptom on my 90ls 400 5 yrs ago and when I changed the spindle, the (this includes hub,rotors,ball joints and pads) the poroblem went away.I am confused on this one.My problem must be between my left and right tire rod(never touched but just disconnected from the arm),left/right wheel bearing(hub),drivers side balljoints,left/right calipers(original and never changed) and upper control arms on both sides.

blkstealthpaid4

My uncle asked the same question you did Damon and I answered "yes" but I am now realsiing that damn cable is not plugged.Will carsontoyota have a diagram of exactly where this cable goes?

skperformance

iTrader: (6)

Cable plugs onto the back side of the hub does it not?
I hope you ordered an ABS hub that has the sprockets for the hall magnetic senor.

You should lube the pistons just like the slider on every brake job.
It will never happen from a mechanic but a solid technician who knows his job will. You need to pull back the rubber seal to get it in there otherwise it can gum up with left over/dried brake fluid and unbalance the pistons especially on a 4 piston caliper like the LS.

blkstealthpaid4

I am going to see my uncle today and I think Damon hit it right on the head since he has had this same problem (after research) with his back wheel.
Please take a look at this pic http://www.lexls.com/tutorials/suspe...flowerarm.html

Please read this and take a look at pic # 3 "3) Remove the two 10mm bolts for the front speed sensor.............."

Is that not the speed sensor?If I am right this does not control the pulsation in the pedal or it has nothing to do with abs right?I know this tutorial is for a 1st GEN, but it is very similar to a 2nd gen.
If I do remember the cable I have disconnected on the drivers side, is the ABS Wheel Speed Sensor which may go into the calipers etc...Will someone have a better pic of where this plugs?

damon

Well hell, my diagnosis appeared a lot more impressive before you did a search!!

python

iTrader: (4)

the pads u speak of are ADAPTIVE ONE PADS, they are made with two different type pads, one for the inside and one for the outside....how long after the brake job did it start pulsating? if it was instantainiously then i would think u have other problems or the rotors were not turned correctly, if it was a couple of days then the brake job was not done correctly and things were not lubed like they should have been