Hi, i have just purchased a sierra xr4x4 with the intention of putting on road (it has been off road for a while!!)
Anyway, when driving the car, even just trickling down the road the brakes are pulsating as though the abs is kicking in all the time, i have removed front and rear brakes and cleaned up pads and discs and made sure pads aren't stuck, there is no gaps and pistons are coming out ok, discs do not seem to be overly bad, someon told me it probably is abs but not pump or module but maybe a sensor, i don't want to be replacing parts that don't need replacing so was hoping someone might have some experience with this
any help would be gratefully appreciated

thanks graham

 

sound like the abs mate, check all the sensor rings are clean and free from rust etc,

cheeRS nick

 

As above^^ thgis is what I would do first, any rust or broken segment will cause this on the ring.
tabetha

 

will try these thanks a lot