The older BX tractors had problems with the quick disconnects, where they would pop off, even though they were completely seated properly when installed. I have never been able to get an explanation as to why this happens. On more than one occasion, I found my hydraulics not working properly, and would have to hunt to find which disconnect had popped loose. The disconnects were manufactured by Parker, and I believe that it had a design flaw, that they don't want to admit to.