I added diesel to the hydraulic tank in my bobcat and never an it. I drained the tank, refilled it, and now the hydraulic system wont work.

Probably the same as a car and needs a sealed system for Pump, Emissions and Evap.

https://www.google.com/search?q=bobcat+863+service+manual+pdf+free

Fixya isn't really a heavy plant site. There must be better forums.

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the hydraulic temperature sender is typically located near the hydraulic oil cooler or the hydraulic tank. It may be mounted on the side of the oil cooler or tank, or it may be mounted on a hose leading to or from the cooler or tank.

hi take look at fuel diesel system there might be : air in the system , blocked fuel filters , dirt in the tank out let hose ,
vacuum in the fuel tank due to blocked air hole in the fuel tank filler cap

if the engine is a petrol engine , you drain the tank and refill with petrol, you may have to bleed the fuel rail but basically it will run a bit rough to start with until all the diesel is flushed from the system then it will settle down
if it is a diesel engine and it is not performing on the bio diesel mix, drain the tank and replace the filter and refill with regular diesel
it may be a bit rough until the system is flushed
If it runs good just use the tank then refill with regular diesel

You will need to take the fuel tank off and empty it, rinse it out with some gasoline, then disconnect the fuel line at the carburetor and drain, then drain the carb bowl by taking the bleed screw out of the bottom. Re install everything. Refill the system. Remove spark plug and clean it, or replace it. Then keep cranking till it fires up and you run the remainder of the diesel out. Recommend adding an octane boost supplement with first tank full of gas, or use premium.

Replace the Hydraulic oil in the log splitter after
every 150 hours of use. Take following steps to
replace it.

1. Make sure all moving parts stops and the log splitter is unplugged.
2. Unscrew Oil Drain Bolt with Dipstick to remove it.
3. Turn the log splitter on the Support Leg side over an 4 liters capacity container to drain the hydraulic oil off.
4. Turn the log splitter on the the motor side.
5. Refill fresh hydraulic oil at the volume as per the hydraulic oil capacity of a particular model indicated in above specifications table.
6. Clean the surface of Dipstick on the Oil Drain Bolt and put it back into the oil tank while keep the log splitter vertically.
7. Make sure the level of the refilled oil is just between 2 grooves around the Dipstick.
8. Clean the Oil Drain Bolt before thread them back. Make sure they are tightened to avoid leakage before place the log splitter horizontally.

Periodically check oil level to ensure it is between
2 grooves around the Dipstick. Upon Lower oil
level, oil refilling is required.

Source:
http://www.qci.net/files/5_Ton_Log_Splitter_-_USE_THIS_MANUAL.pdf

You must drain and refill the fuel tank. Some of these systems use optical sesnors in the injection pump and can be damaged not to mention the damage to the pistons and valves. Great trucks. Drain the tank.

The "MOST EFFECTIVE
" way is to REMOVE The FUEL TANK and DRAIN it By Tipping it over to Pour From FUEL INLET HOSE. Im Sure you Dont want to Here this as it Requires Much WORK . , BUT It IS The MOST EFFECTIVE Way to EMPTY The TANK.

Hi

This is not quite recommended, and to do a 100% job, you should really drain the tank, and refill with just diesel, and renew the fuel filter.

But if it is running acceptably, drive it gently, and keep refilling with diesel.

Good Luck !

Don´t forget to give me a FixYa rating please.

John.