im having trouble with my vacuum wipers they work but after  about 3-4 wipes the left one goes of the outside edge of the windsareen & they stick there i have to put my arm out the window & give them a push or if i take my foot of the throttle they will sometimes thump back into position really hard any ideas on what could be causing it thanks

moz. geelong victoria australia.

graduate 1980, bus, truck, car, hot rod, boat, submarine, hovercraft, hydrafoil, firetruck, mobile home, jet, helicopter, cruise ship, motorcycle, bicycle, santa's sleigh, clock, alloy bullbar, alloy fuel tank, lens, dr who's tardis, matter - anti matter warp drive buffer & y-block lover