CATERPILLAR 247 B Oil Leak
After a few hundred hours this type of oil leak is not uncommon. The joystick starts to leak oil at the control valve. It may take some time to notice this problem because the leaking oil slowly travels down the control pipes before it becomes evident.
Most times this can be wrongly diagnosed. One of the five hoses that bolt onto this valves assembly usually get the blame.
Best practice is to clean and then operate the machine with the valve out in the open.
With the vaslve assembly still in tact, check for oil leakage between the valve assembly and the cast housing that all the pipes blot onto.
In the photo below the hydraulic oil leaked out freely.
After marking all the pipes, that is there position, remove them and dismantle the valve backing plate.
This is what things would look like.
Notice the small black O rings, well they are the culprits. Get replacement O rings from Caterpillar. Remember as with all hydraulic repairs, work clean. Assemble the valve with care and torque the bolts holding the two parts together well.
Secure the valve assembly back where it belongs and enjoy your Caterpillar machine.
