Pulsating the right front brakes

[Lbert]

'96 3.8L 126k

Sometimes I get a pulsating sensation coming off the right front brakes when the brakes are applied mid to hard braking. It is similar sensation as if the ABS is activated expect only the right front will pulsate. The ABS light will not go on so I do not believe it is the ABS; however I could be wrong. No other weird noise coming off the right front during normal driving (turning, street or highway speed). The tires, struts and control arms were all replaced recently. However symptoms did manifest itself even before items mentioned were replaced. The caliper mount and caliper bolts are on tight. I wanted to check the thickness of the rotors but could not find the etched thickness measurements. I'm wondering if the rotors are warped. Any other suggestions what could be the problem?

[tripletdaddy]

Warped or uneven rotor. Happened to me, part of it was rusty. Caliper not grabbing evenly, probably not floating. Tire not properly seated, torqued, rotor not seated properly. Bearing? Something not very loose in the suspension, knuckle assembly, but enought to be noticed when braking.

[northern piper]

when you had the work done, or previously, did the tires get rotated? I've found that some of the oil change techs don't bother to torque the lug nuts properly, some really tight, some not so tight. Add a really hard braking situation and the rotor warps. I have a meter to test run out but when my rotor warped the amount of run out was so small the meter hardly indicated any. BUT, the pedal pulsed without question. I'd check/replace the rotor. If you haven't done the brakes, I'd replace both front rotors and all 4 pads. This is a pretty simple job and can be done for ~$100.00.

My first rotor warped at about 32,000km. They are so thin today the shops routinely refer to them as rasors!

Piper

[Lbert]

Thank you for everyone's input. I have placed an order for new rotors.

[bychance ford]

Originally Posted by Lbert

'96 3.8L 126k

Sometimes I get a pulsating sensation coming off the right front brakes when the brakes are applied mid to hard braking. It is similar sensation as if the ABS is activated expect only the right front will pulsate. The ABS light will not go on so I do not believe it is the ABS; however I could be wrong. No other weird noise coming off the right front during normal driving (turning, street or highway speed). The tires, struts and control arms were all replaced recently. However symptoms did manifest itself even before items mentioned were replaced. The caliper mount and caliper bolts are on tight. I wanted to check the thickness of the rotors but could not find the etched thickness measurements. I'm wondering if the rotors are warped. Any other suggestions what could be the problem?

i have the same vehicle.mine started doing the exact same thing.i am reasonably sure it is the abs unit-all of my other things are good,rotors,pads etc.if you want to make sure like i did,i pulled the 60A fuse for the abs in the engine compartment.brakes are great,no pulsating--the abs is now disabled and the light is on--so now you just have conventional non-abs--check it out before you waste money on everything else.it brakes beautifully without abs(that unit is pretty expensive if you decide to fix it)

[jshort74]

Lbert:
Did replacing the rotors fix the problem? I think I have the same problem on my '95 with a 3.8, but It doesn't feel like a warped rotor. It happens sometimes at the end of braking, right before the car comes to a stop. The pedal pulses very quickly when this happens and I can hear a sound kind of like a spring being sprung. It has been happening for some time now but the car always comes to a safe stop and the brake light never comes on. I have repeatatly checked the brake fluid level and its level hasn't changed. The pads, shoes, rotors, and drums all look good. I might try pulling the fuse next.

[Lbert]

The pulsating sensation on the front right brake is now gone. The new rotors did the trick. I had them on for about 2 weeks and the braking is now smooth. My wife thinks so as well since she is the main driver of the car.

I too, like what Bychance Ford suggested, was so convinced it was the ABS unit but I was proven wrong. Since the rotors were still the originals, 125k later, I figured this route to try first is the best option. I got the pair of Brembo rotors for only $75.00.

Again, thank you to all who responded.

[garync1]

Originally Posted by Lbert

The pulsating sensation on the front right brake is now gone. The new rotors did the trick. I had them on for about 2 weeks and the braking is now smooth. My wife thinks so as well since she is the main driver of the car.

I too, like what Bychance Ford suggested, was so convinced it was the ABS unit but I was proven wrong. Since the rotors were still the originals, 125k later, I figured this route to try first is the best option. I got the pair of Brembo rotors for only $75.00.

Again, thank you to all who responded.

Where did you get brembo rotors for 75.00?? Thats a steal.

[Lbert]

Got it from autohausa.com. They are manufactured in Mexico, though.