300 Troubleshooting of hydraulic and mechanical system (H-mode) H-2 Engine speed lowers extremely or engine stalls
SEN04652-00
H-2 Engine speed lowers extremely or engine stalls Failure information Relative information
• Engine speed lowers extremely or engine stalls. • When starting troubleshooting, warm up the hydraulic oil to 45 – 55°C. Causes
Defective adjustment or 1 malfunction of main relief valve pressure
Presumed cause and standard value in normalcy
2
Defective adjustment or malfunction of LS valve
3
Defective adjustment or malfunction of PC valve
Clogging of orifice or filter in servo mechanism 5 Malfunction of servo piston 4
Defective adjustment or 6 malfunction of gear pump relief valve
7 Lowering of engine output
40-300
8
1
Standard value in normalcy and references for troubleshooting a Prepare with engine stopped, then run engine at full throttle and carry out troubleshooting. Control lever Main relief pressure 26.5 ± 0.98 MPa Relieve arm circuit by moving arm IN {270 ± 10 kg/cm2} If the oil pressure does not become normal after adjustment, the main relief valve may have a malfunction or a defect in it. Check it directly. Differential pressure Oil pressure to be Curl bucket with no Set all levers in measured load (Move lever to neutral stroke end) Difference pressure between pump 1.57 ± 0.1 MPa 3.2 + 0.98 MPa 0 discharge pressure + 10 2} {16 ± 1 kg/cm2} {33 kg/cm and LS valve input 0 pressure If the oil pressure does not become normal after adjustment, the LS valve may have a malfunction or a defect in it. Check it directly. Referring to Testing and adjusting, “Adjusting PC valve”, adjust the PC valve. If the oil pressure does not become normal after adjustment, the PC valve may have a malfunction or a defect in it. Check it directly. The orifice or filter in the servo mechanism may be clogged. Check them directly. The servo piston may have a malfunction. Check it directly. a Prepare with engine stopped, then run engine at full throttle and carry out troubleshooting. Blade control lever Gear pump relief pressure Relieve blade lower circuit
0.98 21.6 +– 0.49 MPa + 10 {220 – 5 kg/cm2}
If the oil pressure does not become normal after adjustment, the relief valve may have a malfunction or a defect in it. Check it directly. If any problem is not detected by checks 1 – 6 above, the cause may be lowering of the engine output. Carry out troubleshooting “S6 Engine lacks output (or lacks power)” in Troubleshooting of engine (S-mode).
PC45MR-3, PC55MR-3