Hello Airjer thanks for your help I checked the right wheels this morning and I couldn't hear the sound, I even lifted the whole front and put the van in gear so the wheels could spin freely at normal speed (I like dangerous things lol) and there was no sound coming from the wheels, checked the brake pads too and it seems I need new rear pads, I have uploaded some pictures of the rear and front pads, is it be possible that the worn out pads are causing both sounds?
REAR PADS:
FRONT PADS:
Oh one more question is it normal that one wheel will rotate faster than the other when both were in the air or only one wheel was rotating with the van in reverse gear. I don't have much knowledge about how transmissions work hehe.
Thanks
Oscar