extreme leak

[kensteer]

my 743 leaks hydraulic fluid at a very high rate while sitting. it is leaking so bad, I believe all 6 gallons would drain in a few days. There is a huge pool underneath and running off the edge of the concrete. Could it be a line that goes from the tank to the pump? Is the pump gravity fed or by suction?

 

[brdgbldr]

my 743 leaks hydraulic fluid at a very high rate while sitting. it is leaking so bad, I believe all 6 gallons would drain in a few days. There is a huge pool underneath and running off the edge of the concrete. Could it be a line that goes from the tank to the pump? Is the pump gravity fed or by suction?

The tank is behind the cab where the back of the seat would be. So the tank is higher than all of the hydraulic lines except the oil cooler.

In other words, if you have a leak below the tank, the whole tank can drain.

 

[kensteer]

Yes, you are correct. The line going to the hydraulic pump is dry. I just checked. It must be a bad seal. But I can see it. I only see the leak dripping off the machine underneath.

 

[brdgbldr]

You could try to pressurize the tank with air to find the leak since you think the leak is between the tank and the pump. Just don't put in too much pressure. A shop vac set up in reverse would work well.

 

[kensteer]

Should I put dye in the hydraulic fluid?

 

[brdgbldr]

Should I put dye in the hydraulic fluid?

My thought is that if the leak allows the tank to drain, if you pressurize it with air and no fluid, you will be able to hear/see where the leak is because of the air leaking out.