Brakes pulsating
 

I have a 1997 E300 and I feel a pulsation in the steering wheel when the brakes are applied; particularly when I am decending on a grade. This is intermittent. I replaced all four rotors which corrected the problem for approximately 3000 miles. However, it is starting again. I have checked the rotors since and there does not appear to be warpage or any irregularities.

You have to make sure and put a little anti-sieze on the contact surfaces of the rotor to the hub.

Also, you could have been braking and hit a puddle of water and warped them again. Or, a two footed driver will cause this quickly.

Or you may have a seized brake caliper which always keep pressure on the brake pads with the result of overheating the brake rotor.
Jackd

Benzmac:

Are you serious? Hitting a puddle of water can warp the rotor.

Thanks
Car Nut
99 E430 Sport

CarNut,

I bet if your brakes are hot enough it can happen (and if they had been machined, that might make it more possible).

"Are you serious? Hitting a puddle of water can warp the rotor."

You bet it is. I had brand new rotors warp on me with less than 1000 miles. I complained to MB about it and, after some discussions, they replaced them. The MB rotors are not ventilated (300E) and are prone to heating/warping. They are inexpensive but...

Did you torque the lug nuts properly?

In the old days you could tighten them right down and it didn't seem to effect anything, now a days with everything being lighter and thinner torque is very important.

Sometimes you can get away with just re-torqueing them, if that doesn't work do a run out check on the rotors, no sense turning all the new rotors if just one or two are causing the problem.

Tox!

after putting new tires on mine , my brake pulsing problem reduced considerbly; could be just your tires need balancing etc., or inflating them to proper pressure. Its the old "is there gas in your car?" first step of diagnosis...

Also, another common way to warp them is too get them really hot through use and then run your car through a car wash or get water on them while you are washing the car. Rotors do not like to get wet when they are hot.

Ali is right. You can warp 'em by just taking them into a car wash especially if you live in the city where lots of braking keeps your rotors at high constant temp. Splash some water on them and voila! warped rotors. Pull over near the car wash, wait a while before going in.

Not sure what type of brake pads your using but a miss-match of pads and rotor could contribute (in other words the composition of your brake bads could create too much heat). Warped rotors is generally a heat thing.

Good luck,
Joel