Hi, I am new on this forum, just joined a few days ago. I am a Hyundai fan for at least 12 years during which I drove an Elantra, Tuscon, still got a Getz and since last year drive a Terracan CRDI 2.9ltr

I just returned from a trip through Namibia having travelled at least 1500km on poor gravel roads. Half way through the trip my ABS braking system gave me problems in that the ABS function kicked in uncalled for at low speeds. The effect was that the brake pedel resisted the braking action by kicking back. The car kept moving forward dispite stepping on the brake. This was accompanied by a load, grinding noise. I inspected the front and rear ABS sensors and found them full with stones and dust. Once I cleaned out the sensors the problem persisted but always just at low speeds. Eventually I disabled the ABS by pulling the fuse for the ABS module and my problems disappeared driving with normal braking action.
Back home I had the car checked and the dealer found some dirt residue on the sensors. They cleaned it and tested it via computer diagnostic which returned no fault. Once back on tar road I haD the same problem again at very slow speed of about 10km/p.h. I tested the brakes at high speed and the ABS kicked in as one would expect, no problem. I returned the car to the dealer who kept it for a few hours and then I got the call from Hyundai stating that the ABS pump needs to be replaced at a cost of R 27,000,00. My car is 3.5 years old with 50000km travelled. I believe that the ABS pump shouldn't pack up at that kind of distance travelled. But I also believe that Hyundai has not tested the system properly. The fault occurs only intermittantly which is suggesting that there may be a loose connection or dust problem. Has anyone had similiar experience and can suggest my way forward?

 

That's normal operation for a car with ABS on gravel. It's one of the reasons I dislike ABS. Because it's very easy to lock a wheel on gravel the ABS will kick in and actually hurt braking performance. There is nothing wrong with your car. You just have to modify your driving style when on gravel with ABS.

 

Thanks for your input. I am quite aware that ABS can be activated quite easily on gravel road. That's why a lot of 4x4 drivers de-activate the ABS system when going off-road. My problem however seems to be different and it now appears that it is unrelated to the gravel road as the problem persists on tar road. It develops over a period of 40...60 minutes of driving and only when braking at very slow speed such when approaching an intersection. I have now been test driving the car with a Hyundai specialist and we connected the car to the computer whilst driving. When the problem occured the computer indicated no error code at all. The technician however now thinks that there maybe an air build-up in the braking system and suggest to start with bleeding that. The other suggestion was made that it could be the master cylinder. The ABS pump was activated multiple times by the computer and it functioned 100%.

 

Hi, did you fix the fault, I have the same issue.

 

Unfortunately, every time an ABS symptom appears it is not always a component failure.
Intermittent connections a good part of the time are the culprit. The problem is to pin down the area and go from there.
A dealership should have the equipment to tell which wheel has the problem and their scan tool should be able to provide a graphic picture of what is taking place and that usually narrows it down quite a bit.Now that you have some idea of how it is diagnosed , just ask the right questions and hopefully the tech can provide the answer..