I wrote this on another post too, but figure I might get more answers posting here.


I just had my '12 countryman for about two weeks, but lately, I noticed when I brake to slow down (eg, approaching to a red light, or about to make a turn) and hit a bump on the road, felt like the brake lost grip/contact for about half a second. It doesn't happen in slow speed or flat road.

When it happened, I could feel the brake pedal "bounced" and it felt like there was something (rocks, ice, slush, but apparently, none of these) between the brakes and the wheels, and the brakes just lost the grip and let the wheels skid.

Not sure if my ESL English can explain this issue clearly.

It happened in a short period of time but enough to give me some uneasinesses. I researched online and some people claimed that was caused by the regen brake, and some claimed that was when the traction control kicked in.

Does anyone experience the same problem? I'm just worrying about if that's something wrong with my brakes.

 

My experience is that, in spite of my hope for better, my ALL4 tends to lose contact between the tires and the road when things get bumpy. This could be the suspension tuning and/or the runflat tires. When I hit bumps while going around a turn, the car can go sideways briefly until traction is restored. While I haven't noticed the reduction in braking when encountering bumps, it would be not a surprise. Dynamic Stability Control could be participating to keep the car under control - but there is no regenerative braking.

 

Too hard to tell by your description. Could be the traction control. I would try to duplicate the circumstances and see if it happens again. Bumps in the road can make the car feel "different" when braking, but unless you have more of an issue personally I don't know how concerned I would be unless it gets more severe or happens in other circumstances.

 

Sounds like ABS to me.

 

Just like in yourother post...
No regenitive braking on a non hybird.
You are driving too fast for tye road conditions, activating the abs when the tires loose grip due to the bumps....when this happens, it lets the tires spin, rather than skid, and as the cars weight is back on the wheels and you gain traction, braking is added back in. Basic abs. You would have skidded without this system, possibly out of control. Slowdown.

 

+1 on normal ABS brake pedal feedback.

Should a tire/wheel lose grip momentarily, the ABS kicks in, as it should, and you'll feel that in the brake pedal (it will pulse / hammer / "bounce", just as you described).

Find an empty parking lot on a rainy (or snowy) day. Try a maximum stop from 25 mph or so, locking the brakes on purpose. You'll feel the ABS kick in, or should, with that same sensation through the pedal.

 

Thanks guys, new knowledges for me in 2012! I may have to prepare to slow down ahead of time when I know there will be bumps on the road. Coz the feeling of the ABS activating is no fun! Felt like the brake is grinding the wheel! (or I can wish they fix the road in NYC!)

@ZippyNH: thanks for replying both of my posts.

 

I drive a Clubbie and there is one corner in town were there are awful bumps in the road leading to a narrow bridge! I do slow down, but it does skip on this corner, the brakes act as you explained and the car jumps out into the corner a bit. I have yet to drive it again with my non runflats, so not sure if that would help. Just be aware of any rutted cornering!