ABS question

I have a 2002 MS 4x4 .Today in the ice and snow I noticed that if I hit the brakes on snow or ice I get a pumping feel and a grinding noice from the brake pedal.Is this normal?? I was in AWD not 4 .Thanks

Reply to
rwcos
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Completely normal. Its simply the ABS doing its work pulsing the brakes to keep adhesion while maximising braking effort.

Stewart DIBBS

Reply to
Stewart DIBBS

Sounds like the ABS is working to me.

Reply to
The Brown & Ollis-Brown Family

Weird whirring noise, light to medium vibration on the brake pedal, and the tires sort of chomping on whatever it was you were driving. That's normal for ABS. It may even flash the ABS light briefly while they work in some vehicles.

Reply to
DragonRider

in article snipped-for-privacy@4ax.com, DragonRider at snipped-for-privacy@comcast.net wrote on 12/6/03 6:57 PM:

Thanks for the quick response .The reason I asked this was because I never experienced that on dry surfaces . Would the same thing happen if I slammed my brakes on a dry surface???

Reply to
rwcos

Yes. The ABS system is a high pressure pump that will interupt your brakes and pulse them very rapidly (up to a 100 times a second in some cases). Because the brake pedal is linked directly to the hydraulic fluid that goes into the ABS (even with the aid of the power brake system) you will have some direct connection to it as the system pulses the fluid. Think of it similarly to holding onto the end of a stick then touching the stick into a moving fan blade. You will feel similar amounts of vibration.

The difference is that in the dry the traction limits are much higher and the system would take a VERY firm stomp on the pedal to activate. If you find a dry area with no one behind you (parking lot is good) get out and stomp on it a few times and get used to what it does and how.

The only time you need to worry about the system is if the ABS light (usually yellow) comes on and doesn't go off. Even if the ABS system fails, your brakes will still function normally unless you are out of fluid.

Reply to
DragonRider

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