I found a guy selling a 80's 722 Bobcat with a 4 cyc gas engine in it. He says evereything works as it should for a machine its age except that the steering sticks "sometimes." It looks decent enough in the picture but until I see it for myself I guess I won't know. I am not exactly sure how the whole drive system works but I am assuming the engine drives a hydraulic pump which in turns supplies oil pressure to all the hydraulics and some sort of "orbital" drive to the wheels. Am I close or out to lunch? When I test this thing out and if I can lift a load with the bucket I going to assume the hydraulic pump is good and the problem is somewhere around the drive. PLease give me some input on what to look for and how to field test it to determine the problem if possible? And if it is worth putting some money into it? I plan to use it to putz around on my hunting property. He isa also asking $3500 for it. THX
There are 3 pumps in the unit. 1 for the lift arms and 2 for the drives, 1 for each side. the drive pumps each power a drive motor which powers the axles through drive chains. If the drive controls are sticking it shouldn't be too hard to figure out as the controls on the 722 are just mechanical linkages, I think. As for pump condition you are correct in that if it will lift a full bucket the hydraulic pump is probably ok. To test the hydrostatic pumps, drive the machine into something that won't move but where you will have good traction, a granite curb with the tries in pavement for example, and try to push by slowly moving the drive levers forward...maximum torque is with minimal lever movement...you should be able to lug down the engine to stall if the tires don't spin and the pumps are strong. If the tires don't spin and the motor doesn't lug down there is a problem somewhere. Oh...make sure you are testing in low range ...I think the 722 had a high/low range lever. Also make sure the machine is warmed up before the stress testing.
Thx for the reply. CHecked out the Bobcat and everything worked as it should until I put it under a load like you mentioned. Anticipating the motor to stall out while the machine was underload it did not. Strangley it bogged then the rpm sped up and it had almost no power seconds later it would recover and had power again. I decided to let this one go and keep looking, probably for something a little newer. THX again.
sounds like a possible filter problem or low oil in tank or not getting to drive pumps.
On a 30+ year old machine could be a lot of things....ok if you are looking to tinker, not if you want to use it consistently. imo