Hello everyone , machine all of a sudden started moaning like the pump was cavitating. I made sure the pump was not air bound and even primed it too make sure! The light on the dash for hydraulic pressure is on also dont know where to start ? When its cold and you start it the travel alarm goes off?
Engine manifold boost is used to pressurize the hydraulic tank. IIRC, once the hydraulic fill cap (with O-ring and brass washer) is reinstalled, the machine is started, brought off idle (notch 3 or 4 is sufficient), and the boom is raised to stall, and held there for 5-10 seconds, or until the light goes out (assuming it's the hyd tank pressure light). The machine is also equipped with two hydraulic filter restriction sensors, one on each hyd filter assy. Water can enter the switch assy, resulting in corrosion, that will turn on the plugged hydraulic filter light. My 4SS 345BL had a service letter/ campaign to replace the hydraulic pump due to premature failure of a thrust washer. Tore down the core, and mine was good as new inside, but, it was warranted by the dealer, and I only paid for the service call and labor. Mind you, I was under 5000 hours. Have you inspected (replaced) the return filters (I prefer the 179-9806 over the 126-2081)? Has the hydraulic oil been sampled recently? As for the travel alarm, you've got a failed pressure switch, or something sticking a valve. If the alarm sounds at key on (engine off), it' definitely a bad pressure switch.
jumped the pressure switch light stays on even charged hydraulic tank 10 psi and the pump still moaning like its derated and the engine is loaded
I would pull the strainer out of the tank and take a look at it.
figured it out there is a one way check valve that is inline with the boost line of the intake manifold right before the tank pressure sensor .Took it out ant it would allow air to go back the opposite way so the tank would never pressurize