[jon cox]

My wife has a 2004 Kia Picanto 1.1 and she has been recently complaining of a "hard pedal" and the ABS operating sometimes when braking at speed on the dual carriageway.
I took the car for a test drive today on a quiet dual carriageway and at 70mph I braked reasonably hard to pull into a layby.
The pedal felt initially hard to push and almost immediately I could feel the ABS working as the brake pedal started "hammering" against my foot.
I released the brake and tried again but for the rest of the journey it was fine and the brake pedal felt easy to push as it normally does..
I did some more braking tests at around 30-40mph and at times I could feel the ABS working although the road was damp and the front tyres aren't great.
Has anyone any ideas as to why the pedal might go hard and the ABS operate when braking at higher speeds please?
The ABS warning light comes on when you turn the key on and then goes out after a couple of seconds and never lights up during driving.
Thanks for any replies.

 

[Jukia]

It could well be an ABS ring at fault. These is a toothed wheel that fits round the driveshaft that the ABS sensors monitor. They rust over time until they split (this happened last year on our 2004 Picanto). Where they split there's a greater than usual distance between one tooth and the next which confuses the ABS sensor into thinking the wheel has stopped rotating and triggers the ABS. I replaced an ABS ring on ours and fixed the problem but it was a PITA of a job and needs tools like a 3 leg puller to get the hub off the driveshaft. Job for a garage unless you've got the tools/time/experience (and a nice warm garage to work in at this time of year !). To see if this is the fault you need to take each front wheel off in turn and get a torch and screwdriver to the ABS ring behind the hub and probe around while turning the driveshaft to see if you can prise the ring apart between any of the teeth.

 

[Siomel]

Jon, I think that test drive of your wife's car especially braking system should be checked by mechanic in service center. That is really serious stuff I think.