Strange braking issue

Ever since I met the love of my life, my C4S it has had a very subtle quirk that is starting to annoy me a bit. When braking at low speeds it feels like it is braking, then not braking so much then braking again - at regular intervals. Nobody else in the car has ever noticed it and I don't think they would unless they were as anally retentive as I am. It's a kind of a pulsing that is so subtle I'm sure most wouldn't notice. Braking from high speed is fine strangely. I put it down to slightly warped discs but I changed these, and the pads of course a while ago but it's still there, almost imperceptible, but there. I have cleaned the mating faces again and re-seated but it's still there... Any suggestions from the pork massive? It's just bugging me, that and the bloody irritating rattle behind the dash that seems to move around the bloody place all the bloody time

Might it be something ABS - related, to do with, say, a faulty sensor or ABS unit? Hopefully not the latter as I would imagine they are expensive. Wouldn't a diagnostic check show if there is a fault somewhere? Worth getting done if only to eliminate some components.

Wouldn't the ABS be a bit more noticeable though? More like rapidly stabbing the brakes in the same way my missus often does for no obvious reason (not in my car obvs!) This is really, really subtle, I mean really subtle, pretty much not there at all. Not like the bloody irritating bloody rattle that I can't bloody find despite having the bloody dashboard out bloody twice

True, but I wonder if something in the system is just starting to fail; the pulsing effect does suggest an ABS fault, but I'm no expert. Worst case would be an intermittent fault which could be a problem to find. Could be something simple that a diagnostic check might show up or at least identify a wheel that was suspect. Is there no friendly Indie near you with the right gear? Or perhaps take a loan out and book it into an OPC... Might it be tyre or wheel related giving the effect of slight on/off braking?

More likely to be be pad deposits on the discs than warped discs. Some people sand them to remove. Also check your discs for cracks, these drilled discs are awful for cracking if you use the car properly. Better grooved discs I think if you are hard on brakes.

Thanks for the replies. It did this strange thing both before and after new discs and pads so maybe an ABS fault I guess.. I do have a very good indie near me, here is a blatant plug...Performance Porsche at Brighouse. I would need to sell a kidney to go to an OPC Also new PS4's recently so unlikely to be tyres I will try a diagnostic or perhaps just live with it. Unlike the bloody dash-bloody-board rattle that gives me sleepless nights

If new pads and discs we can rule out brake judder (warped disc effect ) These cars do suffer .. well they can have a problem with water ingress in the servo .. there is a modified setup which isnt cheap .. This is mainly for a hard pedal though and doesnt really fit your description . At low speeds the abs sees a slow pulse .. its a high low voltage at the sensors basically .. it any of the rings the sensors use are heavily corrodedit can almost make one segment join another .. the car will see what it thinks is a lock up of x1 wheel and activate the abs .. as this is quick and at lowspeed you could in theory get a pulse sensation . Post here about it .. http://911uk.com/viewtopic.php?t=131931 dash rattle .. hmm .. get a sound clip .. and a good one and ill have a go. There are many things im afraid for this but a sound clip will give me / others an idea . If you do it as a video i can post it on you tube and re post it here if you dont have an account .. email it to me .. [email removed]