I recently purchased a 763 Bobcat that had been obviously mistreated and poorly maintained but I already owned a 751 so they matched up for parts exchange fairly well! I inspected and transported the 763 to my farm where I began my process of power washing and servicing my 763. When I had unloaded the machine I found about 1/2 gallon of hydraulic fluid all over the trailer and inside the engine compartment and was highly concerned. My initial trouble shooting found that the previous owner had cut a 1/2 inch hole in the hydraulic fill cap? This sent alarms as I expected the machine had been starving for hydraulic oil at some point! I open the cab and remove the side inspection covers and found a full cavity of mud, grease and oil saturated! What a mess! I pressure washed for three hours and finally could see the hydraulics on each side and the mess removed. At this point I found the culprit causing the hole in the hydraulic cap! The hydraulic tank vent cap was totally covered with 1/4 inch of hydraulic oil saturated dirt causing no venting to occur. I replaced the hydraulic fill cover and cleaned the vent cover and ordered a new one. This cap needs maintained on a frequent basis!
763 Hydraulic caused by former owner
- Thread starter WVRoger
- Start date
Sapientoni
Well-known member
- Joined
- Jun 13, 2025
- Messages
- 103
The oil spillage might mean, it had a hydraulic problem and the user just kept adding oil. Excess oil will be expelled when the cylinders are moved sometimes. Something was causing pressure in the system to spit the oil out. Maybe a cylinder seal is bad allowing blowby causing foaming in the reservoir. For certain the filter probably needs changing. The filter is on the suction side I would expect? Maybe the pickup has issues?
When I purchased the 763 skid steer I operated it on the ground prior to loading and inspected it visually where I could! I noticed the hole cut in the hydraulic oil fill cap but was not concerned at that time. There was no hydraulic oil visible dripping on the ground around the machine. I loaded the machine and drove 80 miles home and when I arrived I saw oil all over the trailer and inside the engine compartment. I power washed the machine for a full afternoon to get all the dirt and grease out of the compartment under the cab. I sealed the cap back up and removed the 1/4 inch of crud around the vent cap. I have operated the machine now for about 10 hours leaving the side plate off so I could view inside for oil leaks. No leaks at this time, therefore I came to the conclusion that the hole and bouncing around caused the leak during transport and there were no actual leaks.
