Hey everybody, On my olde 3400A the outriggers are no longer holding. They drop fine and lift the machine but after a few minutes I notice that I have fallen back down again. Also the boom (or is that the dipper? the first arm connected to the machine) drops slowly as I drive around. The boom always dropped a little but now it is annoyingly bad and as this has gotten worse this outrigger leakdown started becoming noticeable. I wonder if these two things are related? Am I looking at a ram rebuild on all three or is there something else I should look at before I begin crying?
Most likely culprit in all cases is tired piston seals. One brute force test would be to put a ball valve in the line to the butt end of one cylinder at a time, put some load on it, then close the ball valve and wait. If it still leaks down, since the oil cannot flow past the ball valve, it must be leaking past the piston seals. If the cylinder does not leak down with the ball valve shut, then the problem is in the valving. Make sure you don't put the ball valve in the line to the rod end of the cylinders, you could end up with a shattered cylinder tube, just FYI.
Sure sounds like the piston seals as mentioned.