Home » 770G and 772G Off-Highway Truck (OEM) Hydraulic and Braking System » 770G and 772G Off-Highway Truck (OEM) Hydraulic and Braking System: Hoist System Troubleshooting

Tuesday, January 22, 2013

770G and 772G Off-Highway Truck (OEM) Hydraulic and Braking System: Hoist System Troubleshooting






Hoist System Troubleshooting

(1) Gear Pump (Hoist)
(2) Outlet side(3) Inlet side
Performance tests can be used for diagnosing poor performance and for finding the source of oil leakage inside the hydraulic system.


Problem: The Gear Pump (Hoist) makes noise and the cylinder rods do not move evenly. Also, there is air bubbles in the oil.

Probable Cause

  • The low-pressure relief valve in the Control Valve (Hoist) opens at low oil pressure.
  • The high-pressure relief valve in the Control Valve (Hoist) opens at low oil pressure.
  • There is a loose connection in the oil line on inlet side (3) of Gear Pump (Hoist) (1) .
  • Gear Pump (Hoist) (1) is excessively worn.

Problem: The temperature of the oil is too hot.

Probable Causes

  • The viscosity of the oil is incorrect.
  • The low-pressure relief valve in the Control Valve (Hoist) opens at low oil pressure.
  • The high-pressure relief valve in the Control Valve (Hoist) opens at low oil pressure.
  • Gear Pump (Hoist) (1) is excessively worn.
  • There is a restriction in an oil passage.
  • The load on the system is too high.

Problem: The output of the Gear Pump (Hoist) is too low.

Probable Cause

  • The oil level of the hydraulic tank is too low.
  • The viscosity of the oil is incorrect.
  • Gear Pump (Hoist) (1) is excessively worn.

Problem: The pressure of the oil is too low.

Probable Cause

  • The low-pressure relief valve in the Control Valve (Hoist) opens at low oil pressure.
  • The high-pressure relief valve in the Control Valve (Hoist) opens at low oil pressure.
  • Gear Pump (Hoist) (1) is excessively worn.
  • An O-ring seal failed in the hydraulic system.

Problem: The body will not lower.

Probable Cause

  • There is a problem with the engine speed sensor that is located on the flywheel housing.



If you need more information, You can visit:
http://www.cat.com

770G and 772G Off-Highway Truck (OEM) Hydraulic and Braking System: Hoist System Troubleshooting Rating: 4.5 Diposkan Oleh: Unknown

Artikel Terkait 770G and 772G Off-Highway Truck (OEM) Hydraulic and Braking System: Hoist System Troubleshooting :

0 comments:

Post a Comment

Subscribe to: Post Comments (Atom)