I am having some problems with my bobcat 721, the hydraulic lift works perfectly, but the hydraulic drive motors only want to work when they feel like it. When trying to drive it, it is very jerky and sometimes only wants to turn one way. We have changed the filters twice flushed the oil and put new oil in. I have thought it might be the drive motors or maybe even the vain pump, but am really stumped on this one. Wondering if anyone has any suggestions. Thanks, Mike
While I'm far from an expert on hydraulics I have two Bobcat 5600T Toolcats that experienced huge drive motor issues last winter. The drive motors (I believe) are made by Comer and there was a huge flaw in the sleeves in the motors. The first sign was a plugged filter. After removing the filter I dumped the contents into a pan and could see the metal particles in the fluid. Both units only had 350 to 375 hours on them and the drop in performance was almost unnoticable at first. When the dealer came (with a big semi) they barely had enough power to drive onto the semi. The bill for the fix was over $14,000. While I have not confirmed it, I have been told that the drive motors are in quite a few different pieces of equipment.
The 721 is a flawed machine IMHO. I would bet its the drive motors. My dad has one of these. He has it apart continuously. The hyd. system has been apart more times than I can count. If you like wrenching on a skid steer its a great project machine. I finally conviced him to get a new one (Case 430). You will most likely have to pull the drive motors and take them in and have them tested and eliminate that as a potential problem. As long as you have them out I would rebuild them regardless. If they are not bad now, they will be.