Pulsing on the brake pedal

[Mikey]

Hmmm, what is going on here I ask myself. All of a sudden I have started getting pulses of pressure feedback on the brake-pedal when I brake. It appears to occur at the rate of 1 pulse per wheel revolution, and it feels like someone is kicking the pedal back at my foot.

It doesn't always happen, there's no particular rhyme or reason to it happening, but when it does it is accompanied by a sort of rattly noise.

So I trotted down to my trusted local oily chaps, and they replaced the rear discs and pads. They said that the surface of one of the pads had bonded itself to one of the discs. This sounded like a very reasonable explanation, particularly as I had previously encountered a momentary resistance when driving off one morning, followed by a clonk noise and a subsequent lack of resistance. The pad had stuck to the disc overnight, and then torn the surface off the pad when I drove off resulting in a lump on the disc - yeah, I can believe that.

But the problem didn't go away 

So I returned to the oily boys and they checked out the brakes and were unable to find anything wrong at all. They suggested that maybe the ABS was responsible, but there's no lights coming on (and yes, the bulb does work).

So I'm bemused. Any thoughts anyone ?

[sgould]

Welcome!

It would be worth checking the toothed ring behind the brake disc at the front.  This can crack.  The extra gap in the toothed ring can confuse the ABS and cause the system to work when you brake as it misreads one wheel speed and thinks you are skidding or locking one wheel.

It's part of the CV joint

[Mikey]

Aha, that's definitely got potential. I'll take a look at it when the weather is a bit milder (I gave up lying under cars in freezing cold weather some years ago) and will let y'all know how it turns out.

Much appreciated, many thanks.

[TomPaine]

It's what sgould says. Cracked gaiter / cv joint. You get pulsing on gentle braking as the ABS mistakenly kicks in.

[Mr Linear]

Maybe its just the ABS doing it's job...

I was out driving last night and the abs was cutting in now and again as the roads are not the best at the moment!

Mr L.