Changing buckets is far easier these days thanks to the quick change bucket harness. Most rubber tired machines and excavators come equipped with one. They consist of a bar and usually two bolts to hold the bar in place.
The downside of quick change harnesses is the increased risk of the bucket coming off. With the old style it is easy to see from the operator's seat if the main pin is coming out. On a quick change though the bolts that hold the lock bar tight are not visible to the operator from the cab. The bolts could loosen and go undetected. This scenario can be greatly reduced by following a few guide lines. The most obvious one being to visually check to see if the bar is securely fastened.The bolts should be tight and nylon locking nuts should be used. When the bar is being tightened down it should be tightened and then hammered and then retightened, this process should be repeated until the bar stops moving in. Spare bolts and nuts should be kept on hand so there should never be a reason to operate the machine with only one bolt in the bar if two are required.
Loosening of the bucket bar while operating can be greatly reduced by keeping the meeting surfaces of the bucket and harness clean of all dirt. Dirt between the surfaces will pound out eventually causing the bar to become loose. Care should also be taken when moving spare buckets around. There is a tendency to clamp it any way possible and move it as required. The problem with this practice is it can dent the harness on the bucket which will cause the harness on the machine not to fit down into it properly, and then as the bucket is used the dent will flatten and the bar will loosen.
If the machine is equipped with a thumb it can be used to hold the bucket from curling while the machine part of the harness is pressed into the bucket. This action will aid in the bar being tightened to its final position.
The quick change like all components of the machine should be visually inspected often, and most importantly the bolts have to be kept tight and the nylon lock nuts replaced when they become worn.