743 Hydraulic leak - most likely culprit

[remendab]

My 743 with around 9000 hours on it has started leaking hydraulic fluid from somewhere. It's dripping out the bolt holes under the engine compartment. The floor of the engine compartment is pretty slick with fluid. I've take a quick look in the engine compartment and cannot seem to see where the leak might be originating. It seems like a fast leak as about one hour of operation is taking the level from the top of the sight glass to the bottom of the sight glass. I have not opened up the cab and taken a look under the seat yet, if/when I do I wonder where the most likely culprit under there might be? Please if anyone has any ideas where to start looking for the leak I'd appreciate it. Thanks R-man

 

[Kermode]

Have you ran the engine with the cab up and looked for the leak? A leak that bad should be spraying oil all over. It could be a blown o-ring on an ORB fitting but more than likely it is a blown hyd hose. Check the underside of hoses that lay across other lines or that rub on the frame. Its also possible that it is a blown hose to the lift or tilt cyl, you may have to operate the hydraulics for the leak to show up.

 

[remendab]

Have you ran the engine with the cab up and looked for the leak? A leak that bad should be spraying oil all over. It could be a blown o-ring on an ORB fitting but more than likely it is a blown hyd hose. Check the underside of hoses that lay across other lines or that rub on the frame. Its also possible that it is a blown hose to the lift or tilt cyl, you may have to operate the hydraulics for the leak to show up.

Just took a look with the cab lifted. Not nuch oil there. I did some cleaning and ran it again. Seems to be the most accumulation now on the right of the engine, way at the back of the compartment where there seem to be several metal hyd lines goin in/out. I mean way at the back - engine pulling back. Any ideas on any thing I can check without pulling the engine? thanks

 

[Fishfiles]

Just took a look with the cab lifted. Not nuch oil there. I did some cleaning and ran it again. Seems to be the most accumulation now on the right of the engine, way at the back of the compartment where there seem to be several metal hyd lines goin in/out. I mean way at the back - engine pulling back. Any ideas on any thing I can check without pulling the engine? thanks

you got to find the leak before you go pulling the engine , if you can run it you would probally never find the leak

 

[Dogsluvtrux]

you got to find the leak before you go pulling the engine , if you can run it you would probally never find the leak

Couple things to check...jack up the machine and lift the cab and move your drive levers. I have had two machines in my shop that drove me crazy trying to find the leaks! One was a 7753 that had a loose fitting on a return line from the drive motor...no leak unless the machine was moving. The other was an S220 that had a leak on the lift cylinder...it didn't leak unless the cylinder was extended or retracted, and when it did leak it ran down the cylinder and appeared to be coming from under the engine/hydrostat.

 

[Tazza]

Couple things to check...jack up the machine and lift the cab and move your drive levers. I have had two machines in my shop that drove me crazy trying to find the leaks! One was a 7753 that had a loose fitting on a return line from the drive motor...no leak unless the machine was moving. The other was an S220 that had a leak on the lift cylinder...it didn't leak unless the cylinder was extended or retracted, and when it did leak it ran down the cylinder and appeared to be coming from under the engine/hydrostat.

One of the hoses that split is the hose from the bottom of the control block that goes to the oil cooler. It has a pretty nast bend and splits over time. I'd start there.
Get in there with degreaser and pressure washer. You may even have a rusty hose that runs behind the engine, they rust and leak some times.

 

[sirrandolph]

I am new to the skid steer forum and have a related problem. Do I need to start a new thread or would it be proper to ask it here.