Cat 246B Hydraulic Leak! Where is it comming from?

I was clearing trees a few days ago and stopped to fill the fuel tank, I see hydraulic fluid leaking out underneath. I found a catch pan and basically watched the hydraulic tank empty itself. Since it was dark I left it sit and decided I would look at it the next day. i pulled the belly pan and its dry there, looked all over the engine bay and its dry there too. Decided to get it in a building to work on, had to add a few gallons of hydro fluid to get it in the building, as soon as i added the fluid it started leaking out the bottom of the machine again.

Its leaking near the right rear tire on the Belly, There looks to be a small hole there. I Lifted the cab and removed the belly pan, The belly is dry. Cant see a leak or evidence of fluid. It looks like it would be coming from the area between the motor and cab. Doesn't seam to make a difference if the machine is running or not. Should be easy to find but I haven't found it yet. Checked the chain case its not overflowing.

Unless someone has a better Idea my next step will be to remove the hydraulic tank so i can see in front of the motor. I believe there is the filter return line there but wouldn't think it would leak while the machine is off.

Any Ideas?

The fact that it leaks, running or not, suggests that you have a leaky tank, or a hose problem on the suction side of the pump. I think you are on the right track by pulling the tank (unless there is some other way to check things out). I assume the hyd. tank is plastic so check closely for cracks or a spot where it may have had something rub through it (applies to the pump supply hose too). If possible pressurize the tank (only a pound or two will do-don't create an explosion hazard) if there are no obvious signs of the source of the leak.

I will give the tank a look too but the hydraulic tank is very exposed on a cat machine with the cab raised and I cant see any fluid leaking from the tank. I too me it should be something around the pump, tank and valve, but that area is dry. I just cant figure what it would be that wouldn't spray everywhere, Must be a low pressure line.

The only "low pressure" areas you have are the ones I listed. You said it did not matter if machine is running or not. It may be that the leak is from residual pressure after shut down. It could also be that the machine leaks only on certain functions, leaves a puddle of oil on something, and then drips wether running, or not. How much fluid leaked out? I had a mystery leak on my A300. It would drip from the bottom of the pan but not all of the time. Sometimes it would leave trails, and then not drip at all for a while. I determined that it would only leak after climbing steep inclines. After investigating I found the oil was coming from a missing bolt on the chain case access hatch (did not get installed by the Bobcat mechanic who last worked on it). The incline forced oil to the back of the case and increased the level to the point that it would come out of the bolt hole. Level ground caused no leak (only dirt intake I imagine).

I lost 6-7 gallons of fluid, I basically shut the machine down and it continued to leak until the hydraulic tank was empty.

I am not familiar enough, with your machine, to be of much use from here. Other than to suggest that gravity drained the fluid. Check the bottom of the tank, and the pump supply line.

I appreciate all the help I will give it a good look over tonight and let you know if I find anything.

Guys I am still working on this leak. Another question What Hydraulic fluid should I run in the machine? I have searched and searched and see a lot of conflicting info. I am tired of paying 20+ a gallon from cat this will be the third time i had to completely refill the hydro tank.

I found where the leak is coming from its highlighted in Red Below, This sits on the belly under the pump and is extremely hard to get too. The hydraulic tank dumps in to this valve also. There is a bunch of dirt in the bottom hiding the leak I will wash it out tomorrow and see what I can find. Hate to put more fluid in to get it outside to wash out but don't have a choice I know it will just drain out again. More fluid to capture and recycle.

You can use any good quality commercial SAE10W hydraulic oil in that system (Mobil, Chevron, Texaco, etc). You don't have to go for Cat oil.

The part in your photo that's leaking is the return hydraulic manifold. Lot's of different arrangements of it, you'll need a Serial Number to satisfactorily identify what you need.

BEEN TRYING TO DISCUSS SAME PROBLEM CANT GET IN DO YOU HAVE TO REMOVE BELLY PAN TO GETT TO THE HIDDEN LINES PUMP ECT TO FIND LEAK

earl bass said:

BEEN TRYING TO DISCUSS SAME PROBLEM CANT GET IN DO YOU HAVE TO REMOVE BELLY PAN TO GETT TO THE HIDDEN LINES PUMP ECT TO FIND LEAK

Click to expand...

I don't even think my 248B has removable belly pans. Everything I chased was from the top. In 16 years, I've had just about everything apart on it, and I don't recall removable belly pans.

DONT WANT TO BE THAT GUY TO STATE THE OBVIOUS, BUT, WHENEVER YOU CANT FIND A LEAK, MAKE SURE TO POWERWASH THE AREA WHERE THE LEAK MIGHT BE COMING FROM. AND BRAKE CLEAN IS YOURE BEST FRIEND WHEN LOOKING FOR A LEAK. AND ALL SKID STEERS HAVE REMOVABLE BELLY PANS.

LEGO said:

AND ALL SKID STEERS HAVE REMOVABLE BELLY PANS.

Click to expand...

Yeah, right. Not all skidsteers have removable belly pans.
And, stop yelling

heymccall said:

Yeah, right. Not all skidsteers have removable belly pans.
And, stop yelling

Click to expand...

And IF they do it may only be one in the middle and waaaaaayyyy to small to really access anything...thanks engineers, glad you all know better.....