Cat 320C-Hydraulics stalls the engine loaded or unloaded

[henery]

Cat 320C- hydraulics stalls the engine loaded or unloaded and at an idol or wide open. Injector pump has been redone and all new injectors. PRV Valve has been changed. flywheel sensor also. CAT has been out four times, from different dealers. They say the pump is bad and needs replaced. I took the pump apart and it looks good. I really don't think it is the pump. Seems like the pump doesn't ever destroke and I get the full 80 gpm all the time. Because the machine functions all work quick. I think it could be a wiring problem around the bypass switch under the right armrest. The wires have definitely been repaired in that area. Also, I have unplugged the wires to the hydraulic pump, and it makes no difference whatsoever. If I work the machine very long the hydraulic oil gets very hot. Can anyone help with this situation?

Serial # CAT0320CJPAB05482

 

[DeereKen]

Fallowing

 

[KOBE STEEL]

most common faults that I have come across in regards to the SBS pumps causing engine overloading are the actuators ( pump regulators ) worn between the housing and the servo control spool and the 2 piece swash cradle saddle bearing assemblies binding.

 

[DeereKen]

Thank you for the response. Will check it out.

 

[henery]

most common faults that I have come across in regards to the SBS pumps causing engine overloading are the actuators ( pump regulators ) worn between the housing and the servo control spool and the 2 piece swash cradle saddle bearing assemblies binding.

Not sure what the SBS pump is. I have had the main hydraulic pump apart a couple of years ago and everything looks good. The wiring looks terrible from the main switch, under the right hand arm rest. Someone had told me to check the wiring it may be tied to the PRV valve or the computer.

 

[KOBE STEEL]

SBS should be the model of your pump which may be written on the pump ID tag or it may be omitted. There are other versions of pumps installed depending on the serial break. When the PRV is not working the pump will be set to its highest horsepower setting which can cause a higher loading on the engine. The PSV solenoid is located on the regulator of the pump and has a small flat blade screw adjustment that can be wound all the way in which will override the solenoid and keep the pump at a fixed reduced power output. If this did not fix the engine overloading problem then I would not rule out that the pump still has an issue.

 

[henery]

SBS should be the model of your pump which may be written on the pump ID tag or it may be omitted. There are other versions of pumps installed depending on the serial break. When the PRV is not working the pump will be set to its highest horsepower setting which can cause a higher loading on the engine. The PSV solenoid is located on the regulator of the pump and has a small flat blade screw adjustment that can be wound all the way in which will override the solenoid and keep the pump at a fixed reduced power output. If this did not fix the engine overloading problem then I would not rule out that the pump still has an issue.

Thank you so much for the information. I will try this out and get back with you!