I had a weird issue with the brakes the other day, and wondered if anyone else has experienced similar. I pulled out of the work car park and accelerated up to about 20MPH, at which point the car felt like it lost power and stopped accelerating - pressing the throttle harder didn't make it go any faster (didn't try pressing hard enough to get it to kick down). I let go of the throttle and the car slowed pretty quickly. Accelerating away saw the same thing happen again - accelerate up to 20 fine and then it was like hitting treacle.

 

I pulled over to stop and see what was going on - no warning lights illuminated. The offside brake disks were stone cold as expected since I'd only just started driving. Both the front and rear near side disks were red hot though, so clearly my "loss of power" was half the brakes coming on hard. To test, I re-started the car and drove off again, and it was fine. And has been fine since - pretty much normal fuel economy so far as I can tell, so no brakes dragging.

 

So what might cause half the brakes to trigger? The emergency brake is very obvious when it triggers, lets you know clearly on the dashboard, and would operate all 4 brakes. A sticky calliper would only affect a single wheel, and be unlikely to clear up like that. I assumed that if it was a split brake circuit they were split diagonally, so a fault wouldn't affect both wheels on the same side? So the only thing I can think of is the stability control - except it was low speed, on a good dry surface, with low acceleration, and there were definitely no warning lights for traction or stability control illuminated.

 

I will mention it to the dealer when it next goes in for service, as that is only a couple of months away - it doesn't quite seem worth taking it in just for that as I can't repeat it. Just wondered if it was something that anyone else has experienced.

Could it have been the speed limiter coming on in error?

It did feel like the way the speed limiter acts, but seems weird if it acts by jamming literally half the brakes on rather than reducing the throttle input.