My D7-17A brakes were not working very well. The left one was't working at all. I took the two inspection covers off and found that a pin had fallen out of the linkage. The pin or shaft must be about 7 to 8 inches long with a reduced diameter at each end. Looks like it must go through the brake linkage and hook into a casting that is fixed. The casting doesn't really have a hole - sort of half an open hole that the pin must hook into. Found the pin laying in the bottom of the case where the brakes are at. How should this go back together?? Why did the pin come out? How are the brakes adjusted? Thanks.