Wet brakes grabbing

[nad6211]

Has anyone else experienced a serious case of brakes grabbing, usually after coasting down to a stopping point and applying the brakes at about 6 mph and in cold, wet weather? I have a 2004 with 23,000 miles. Toyota service staff indicate no similar complaints and, of course, I have never been able to replicate the experience while a technician is riding or driving the car. The experience occurs very intermittently.

[rick57]

I have not run into this at work. No warning lights on? Braking ok the rest of the time? Nothing else unusual?

[Sufferin' Prius Envy]

By “cold” do you mean below freezing?
By “wet” do you mean you just drove through standing water?

Wet brakes can cause a grabbing sensation until the rotor and pads are dry. After washing my Prius, I drive around the block and apply the brakes to dry them off. The Prius brakes are very grabby when wet from my car washes! Unfortunately since we have regenerative braking, this method of drying the brakes is not as easy as with standard brake systems, because the Prius mechanical brakes only engage at low speeds . . . so it takes more applications to heat the brakes in order to dry them.

If you got your brakes wet and then the weather turned freezing, you may have had ice on the brakes . . . even more dangerous . . . and difficult to fix.

[m1j1tc0rn]

I have the exact issue you are talking about here.

Sometimes, it even "pops" in reverse when I start it in the morning (like i'm running over a small rock or something).

Anyway, my brakes grab in cold/wet weather, as you mention, and I was debating bringing it in. I actually think they don't always needs cold wet weather, but it hasn't happened in a couple of weeks.

I'm in a 2004 with 18k miles on it and the grabbing didn't start until about 4months ago.

-r

[Brian]

Dido, I washed my car Friday then it rained Saturday. During the rain, it would do the exact same thing. At about 6mph it would just "grab" and stop too abruptly. I thought I must have left soap on the front disc brakes or something.

[jayman]

From what has been described, I wonder if it really is the pad material grabbing on the rotor? Or if it isn't the caliper itself actually sticking on the slide rails. This car has full floating caliper, right?

It's really important to take the caliper off once a year and clean/lubricate the slide points. I do it twice a year - every fall and every spring - but we have a lot of road salt to deal with here.

[Tideland Prius]

Aside from grabby brakes (which I haven't experienced yet), does anyone's front disc brakes squeak when wet?(usually occurs when doing a full lock turn)

[Dion]

My brakes started grabbing after I coasted down a long hill on a rainy day about 6 months ago. Now they grab always when it rains.

[nad6211]

Thanks to all for the various descriptions related to "grabbing" brakes. In fact the brakes do also "sqeal" or sqeak when the grabbing sensation happens. I also notice that backing out of the garage and applying the brakes as I roll backwards down my driveway the brakes have a grinding kind of sound. I am not aware that I have had the brake issues during any weather but wet, cold and wet, cold and slushy, and heavy morning fog and cool out weather conditions. The temperature has been 35-40 degrees, not necessarily freezing, for the brakes to act this way. Never have any warning lights come on and, as I indicated, when the technicians run all the diagnostics they find no problems.

Most of the time what I am describing is not dangerous . . . just a bit surprising and annoying for what is otherwise a comfortable ride. Every once in a while the experience is dangerous in terms of the sudden stop with someone tailgating too closely and, at least as I imagine the possibility, in very slick conditions one could momentarily lose control. I did have one situation with three passengers and the brakes grabbed and the jolt was both a surprise and pretty uncomfortable for one of the passengers who was leaning forward already and had a bit of a whiplash effect.

[jayman]

<div class='quotetop'>QUOTE(Tideland Prius\";p=\"74305)</div>

does anyone's front disc brakes squeak when wet?(usually occurs when doing a full lock turn)[/b]

If by "wet" you mean damp and not saturated, I think most disk brake systems make noise when wet. They also can be grabby if damp. My 2000 GMC Sierra had four wheel disk brakes, and the only time they semed to work well was when the pads were damp, say after I washed it.