Hi, I have a 763 bobcat that I need to get to a mechanic and I'm wondering how to release the hydrostatic system to tow it Thanks
Welcome to HEF Lwaldner. :drinkup Bobcat machines really don't have a provision to release hydrostat drive. First the parking brake is engaged. Even if you remove the parking brake, it won't really free wheel, and attempting to do so could damage drive components. About the most practical thing to do is pull it on a trailer or roll back truck with a winch while skidding the tires.
I have a 763 C Series. It has a Sauer Danfoss Hydrostatic Pump. I downloaded the Complete Pump Service Manual from the Sauer Danfoss website. I wanted a copy to add to my 763 Service Manual in case I need it in the future. As I read the manual I was surprised to read that the pump is designed with 4 Bypass valves. The manual states, “In some applications it is desirable to bypass fluid around the variable displacement pump allowing, for example, a vehicle to be moved short distances at low speeds without running the prime mover.“ It warns “Opening the bypass valves will result in a loss of hydrostatic braking capacity. Take precautions to prevent machine movement when opening the valves.” I extracted these 4 pages of the manual and highlighted the key information. Now the bad news. You have to loosen 4 valves (2 on each pump section). Two are easy to get to on the top of the pumps. The other two are on the BOTTOM of the pumps just above the fuel tank. Getting to the bottom two Bypass Valves maybe doable, but you will probably have to come in from the engine side. You use a 5/16 inch Allen Wrench to loosen the valves (no more than 4 turns). So at least for my loader the answer is the hydrostatic pumps are designed to allow you to tow the machine without draining any oil or disconnecting any hoses or parts. The issue is whether Bobcat left enough room to get to the bottom two valves. I wonder if the engine and pump mounts could be loosened enough to tip the pump up so you have enough room to access the valves? I have not tried this on my machine. Let us know how it goes. As Willie59 stated, you also have to release the parking brake to allow the wheels to turn.
by the time you get around to playing with the HP reliefs, the machine could be pushed, pulled or dragged onto a trailer, and be on it's way in for repairs :drinkup