Brakes acting werid...

[94502]

For some reason my car is very hard to make a smooth stop. I try to press it very very lightly but it still won't stop smoothly. When the car almost come to an complete stop it has this pulsing feeling to it as the manual described. "If the brake rotors are corroded, they will tend to respond to braking with a pulsating effect which even extended application will rail to cure" (page 140 in the manual) Anyone experince this before? I have a 05 4.4 with 10,000 miles on it and it have been like this since I got it.

[jwalsh22]

Sounds like there's something wrong with the rotors, warped maybe? You've got the warranty - take it in and complain about the brakes. Take the tech for a drive in it to make sure they can feel the problem.

[///Bruce]

Try this (it will sound weird, but it might work). Deposits have a tendency to build up on rotors. Different pad types will leave more, others less.

Next time you wash the X, you will notice rust buildup on the rotors. Start up the X, put it in reverse and give her gas enough to get it up to
~15mph and slam on the brakes. Do this until the brakes dry enough and grab the rotors enough to lock the wheels.

This "scrubs" the rotors of miscellaneous garbage. If you read up on the M3 boards, you'll find a lot of us that use this technique to clean off the rotors after tracking our cars.

Hope it helps some. But, at 10K miles, you should not need brakes or rotors yet.

[mrkbbd]

mine does the same thing but I only have 5500 miles. When I'm coming to a stop that I'm trying to keep smooth, the car feels like it slips at ~5mph then stops hard. I think I'm going to try what Bruce said to do because it's highly possible that the brakes have a lot of buildup on them (I drove the brakes very hard for about 2000 miles (at least 10 occurrences of ABS intrusion) then backed off when I cut it a little too close)

[jwalsh22]

build up comes from non-use, am I right? Letting your car sit for two months creates rust, but using them hard and often just wears down the pads faster, right?

[///Bruce]

Build up comes from HARD use. Reason: gases build up between the pads and the rotors. The gases get hot and start to bake the pads. So, the pads give off some kind of goop that sticks to the rotors especially after a hard track run. In our case, the X weighs in in excess of 5000 lbs. Notice how hard it is to stop this beast sometimes in a panic situation? Essentialy, same effect is occurring.

[jwalsh22]

Originally Posted by ///Bruce

Build up comes from HARD use. Reason: gases build up between the pads and the rotors. The gases get hot and start to bake the pads. So, the pads give off some kind of goop that sticks to the rotors especially after a hard track run. In our case, the X weighs in in excess of 5000 lbs. Notice how hard it is to stop this beast sometimes in a panic situation? Essentialy, same effect is occurring.

Oh, I use my brakes REALLY hard and never have an issue with any of this. I guess a track run would do it - shouldn't you have better pads at least if you're tracking the x? And the X only weighs about 4700 lbs according to the manual.

[///Bruce]

5000, 4700.... Whatever. It's a very heavy vehicle. And tracking it real hard is a possibility. You can take it out and get her up to 60-70mph and slam the brakes a few times. That might help.

The first mod I performed on my X was to change out the pads. I went with Rotex. They don't dust, bite good cold and if you use enough anti-brake noise compound, they're quiet too.

Even so, after I wash her in my garage (it's black and I always wash my cars in my garage to minimize dust and water spots), I back it out and go down my street backwards hitting the brakes a few times hard until you feel that the brakes are dry and "cleaned off".

I then pull it back in, wipe off the excess water drops, detail the X and then clean the inside of the rims to clean off the rusty water marks.

[x5user]

Sometimes, it really works.

Originally Posted by ///Bruce

Try this (it will sound weird, but it might work). Deposits have a tendency to build up on rotors. Different pad types will leave more, others less.

Next time you wash the X, you will notice rust buildup on the rotors. Start up the X, put it in reverse and give her gas enough to get it up to
~15mph and slam on the brakes. Do this until the brakes dry enough and grab the rotors enough to lock the wheels.

This "scrubs" the rotors of miscellaneous garbage. If you read up on the M3 boards, you'll find a lot of us that use this technique to clean off the rotors after tracking our cars.

Hope it helps some. But, at 10K miles, you should not need brakes or rotors yet.