mtofell1 wrote:
Definitely use wheel chocks. The trailer brakes are nowhere near adequate for hooking up. Also, best practice is to have the 5th king pin a bit lower and have the hitch "lift" the trailer as it latches. This takes weight off the legs and helps prevent what you are talking about. 5th hitches have a bit of a ramp, presumably for this exact reason.
Then remove the chalk after you have raised the front jacks about an inch from the ground. Then do the "bump test" by using the brake lever lock up the trailer brake, then pull the trailer forward about 6 inches to make sure you have the hitch hooked up correctly, then raise your front jacks completely up.