the masts of a front - end loader are releasably attached to vertical plates of a loader mounting frame located at the opposite sides of a tractor by latch hooks pivotally mounted to the masts and engaged with latching elements carried by the vertical plates . an over center biasing arrangement acts on each latch hook and acts to bias the latch hook to a closed position , but moves over center when the latch is manually opened so as to bias the latch to its open position . the pins pivotally coupling the latches to the masts also serve to couple the piston rods of a pair of loader boom lift cylinders to the masts . extension of the cylinders during detaching the masts from the vertical plates causes the opened latch hooks to be pivoted to the extent that the biasing elements move over center and reset the latches to their closed positions , which positions are conducive for automatically reattaching the mast to the vertical plates .