www.ultimatehandyman.co.uk

Hello,

I have an issue where the rear passenger brake will start to engage and bind when driving after pressing the brakes a few times.

So this evening I pulled the fuse from the ABS as I was confident that the calipers were fine and I replaced the line on saturday.

Voila, the issue is gone and the rear passenger no longer locks.

I stopped the car and replaced the ABS fuse and slowly the issue returns after pressing the brakes lightly a few times. Then when it starts happening and you slow the car to very slow it starts trying to bind harder and will bring the car to a stop. You can drive on if you accelerate as the brakes on the other three wheels are not on. But it is trying its hardest to stop you.

So the question is - is this the abs wheel sensor and if so would this tell the abs to lock one wheel or would it try to engage on all 4 wheels or.....

is this air in the abs module causing the locking of one wheel?

I say air in the abs as I recently changed the master cylinder but this only started happening a few weeks after the master cylinder change and everything has been fine until now since the change.

So have I answered my own question? it is the sensor? but would the abs module try to lock one wheel only?


Barry

Does the rear have an abs sensor?

Do the caliper slide pins seem free, if they're seized they could be the cause.

Also it may help if you tell us which vehicle.

My ABS light came on and the garage told me the following
ABS units very rarely fail ,the brake sensors are more than likely the culprit.
look for metal shavings and other debris that could cause false feedback to the electronic ABS controller. False feedback causes the ABS to trigger when it shouldn’t, or not function when it should.
Also you may have air in the ABS ,it’s very difficult to remove some cars require a scan tool to cycle the pump to remove

Basic ABS can only release brakes not apply them, so unless your vehicle has stability control or an auto brake feature the problem is more likely with the caliper and least with a hydraulic restriction in the pressure release side.

What make, model and year ? petrol or diesel ??

Abs units do fail, esp if the brake fluid isn't flushed