I’m pulling my hair out on this.
The hydraulics on my John Deere 5310 have been working for a while. It was a slow and steady increase in problems. It started with the FEL jerking as it rose. Then the steering turned abrupt. Eventually it got to the point where the entire hydraulic system came to a complete stop.
There was a lot of oil according to the dipstick. So I drained the oil, changed the filter, removed the strainer from the back and cleaned it, and filled it with new oil. After doing that, everything worked like a charm! I cut the hay in my meadow, but after about 2 hours on the tractor the steering started jerking again.
Within a few minutes, the hydraulics stopped almost completely. The loader hardly raises anymore.
One thing I noticed is strange, while operating the hydraulics, I noticed a strange sound coming from below, which sounded like a “pffth pffth pffth”. Almost like an air leak.
Can someone point me to the next step to fix this?
There are several possibilities, but I think you need to check the suction side of the circuit first. Depending on your serial number, the suction line can be of two different styles. In both types there is a piece of hose that connects to the pump. That’s the suction line hose. It is attached to a steel tube that connects to the filter box. In the filter housing, the tube can be connected to another hose or it can fit into the housing with an O-ring.
Also the filter box is connected to the transmission box with a spacer and an O-ring between each joint. If the hose (s) or o-rings do not seal properly, you can allow the pump to draw in air instead of oil. This causes a severe deficiency in hydraulic output.
I have attached images of both configurations. Another place where air can be sucked in is around the pump shaft seal. Since the pump is bolted to the engine, when air is drawn around the seal, small amounts of engine oil can be drawn as well. If your transmission oil is turning black like engine oil, that would be the place to check.
If you still have the old filter, I would cut it open and see how it looks. My opinion is that it is full of dirt. Based on the milky color the water was in the old fluid. You could try to see if you can get a sample of the new liquid out through the filler cap and see what it looks like. My guess is that the tractor was running fine until the filter was plugged and the sound you hear is that the pump is not receiving fluid. I know the fluid and filter are not cheap, but I would consider replacing both. Others may have suggestions on how to clean the hydraulic system or at least the fluid if you want to try reusing it.
UPDATE – PROBLEM SOLVED!
I finally got back to the project. Drained the Transmission / Hydraulic fluid, pulled out the filter screen to the right of the PTO. The filter was full of garbage. I cleaned it carefully with an old toothbrush and some diesel. I have dried it with compressed air. I changed the filter. Let’s fill it again with liquid. And that’s it. A JD service technician told me to inspect the cavity where the screen is located for iron shavings, etc. I used a magnetic extension rod, I had a couple of pieces in there – I’ll keep an eye on that!