[glennpm]

Good call Mart.

The other thing I should have mentioned is that the spring clip that goes between the spring and the backing plate tube may have fallen off. When this happens, the spring will migrate up into the backing plate tube so it becomes invisible. You can check this by pulling the boot on the external, to the backing plate tube, and poking a wire or rebar tie-wire into the tube. which will push the spring back into the "visible" world :-)