Having some problems with my folk's '01 Renault Kangoo van...

Occasionally when brakes are applied lightly at low speed the ABS starts to 'rumble' through the pedal. The rumbling is less severe than normal which makes me think only one wheel is affected? I guess there is some kind of sensor mounted to the hub - could this be damaged or even just needing cleaned up?

Any advise much appreciated,
Iain

check for cracks in abs rings

i would suspect a bad connection
of the sensor being the fault.

maybe the sensor is loose or something..

When it aplies the ruble its because it thinks one wheel is stalled/fully braked

sow it needs to detect no rpm..

because it are inductive sensors the hardly cant know if its the wheel who isn't turning or the sensor wich disconnects / connects..

Tks

ABS faults are usually wiring/connector plug faults, sensor faults or reluctor ring faults -- check the wiring in the wheel arch first. On recent car reluctor ring problems have become more common.


Also based on our the description are you sure it isn't a warped disc.

My wife had this problem. It only happened at dead slow speed. It turned out to me the reluctor ring. That is the ring of blips on the drive shaft that the sensor points at. The ring had cracked in one of the gaps and upset the signal.

will thrid the reluctor ring, either cracked as previously stated by mg david, or i have seen lumps of road tar in one of the gaps cause the same problem. Dead common for cracks on primeras reluctors, and that creats the exact symptoms you describe

Many thanks folks, I will check my rings (oo er) tomorrow. It only does it at very low speed as mentioned and you can almost feel it passing a bad part of the sensor ring each times the wheel turns. Thanks again!

Regards,
Iain

The sensors signal strength rises with wheels speed. Theres almost no signal at 1 or 2 MPH. Problems at low speed can be related to sensor / reluctor wheel gap. If the gap is bigger, there is no signal to a higher speed.

My God you guys are good! Had a look today and discovered one of the rings has a large crack between the teeth. Shouldn't be too difficult to fix...

Thanks again for your help,

Iain