843 leaks hydraulic fluid

My 843 seems to leak oil, even if its been sitting for weeks. The worst seems to be under this connection block where many hoses connect, on the right side and under the fuel tank. There is a puddle of hydraulic fluid there. I do not see anything too obvious. My garage floor is covered with oil socked cardboard, oil-dry and so on.

Can I add UV dye to the hydraulic oil to see if its a new leak vs an old gear oil. Any reason not to start and run the machine with the cab lifted up?

donald73d said:

Can I add UV dye to the hydraulic oil to see if its a new leak vs an old gear oil. Any reason not to start and run the machine with the cab lifted up?

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I'd give it a good clean with a pressure washer and degreaser. It makes it easier to find any leaks.
The most common area is the control block.

Tazza said:

I'd give it a good clean with a pressure washer and degreaser. It makes it easier to find any leaks.
The most common area is the control block.

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Is the control block the block with many hoses going into it on right side under fuel tank? Is it normally the control block itself that is leaking or a hose going to it. Is the control block the same as the control valve? They sell a seal kit for the control valve.

donald73d said:

Is the control block the block with many hoses going into it on right side under fuel tank? Is it normally the control block itself that is leaking or a hose going to it. Is the control block the same as the control valve? They sell a seal kit for the control valve.

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Yes, that is the control valve. It could be a hose going to it, but mostly the seals inside it are what fail and start to leak.
With that said, i had a hose from my pump to the control block start to leak on my machine. So to be 100% sure, you do need to give it a good clean to find where the leak is coming from.

I have a 843 that has a hydro leak in the spool valve area, I put new quad seals in and the back side towards the engine is not leaking. The fluid comes out seemingly under the valve assy. If I put the arms up the bob tack with out a bucket drops with in a few hours and if I put a log splitter on it it leaks like crazy when I try to rotate it up. Question can I hook up a hydraulic pump in line some where to pressurize the unit with out having to have the engine running? I have a unit with a reservoir and a remote on off control 3200 psi 3.7 GPH I could tee into the system so I could pressurize at will as I look for the leak. I am going to put dye in the oil and use a black light as I do with engine should work with hydraulic as well. If I do this where would be the best place to tee it in? The 843 has no safety stuff so I guess I will not even have to turn the key on. I have the bobcat blocked up so the wheels will turn and a safety block on the lift arm. The cab is as well up and held with a strap so it cannot fall. See if the engine is running I need to crawl in the engine compartment to get to the valve body to see it and that is uncomfortable for me. Its the bob tack that drops not the lift arms. It seems to coincidental that the bob tack weeps and it leaks like crazy when you have a load on it like a heavy long splitter that sticks out 10 feet. But I cant load the tilt to get it to leak badly safely with the engine running and be in a position to see where its leaking? None of the hoses are leaking that I can see. That was my first thought. All leaking is at the valve body area! Some one replaced most of the hoses recently they look fairly new. I know 843's are leakers no one has a dry one. But this a gallon in 10 min when loaded and I very slow weep when not. Its defiantly in the tilt circuit!

Any help.