hello ive never known this to happen may be theres to much oil in the forks. should only be 180ml in each fork. to clean the fork caps take them off there should be a tiny nut on the bottom undo it be carfull theres a small spring and ball bearing inside soak them in some wd 40 then dry spoke the vent hole with some thin wire then put them together. but my gess is theres to much oil in the forks.