CAT 930K Implement pressure problem

[Helbert Fonseca]

Hello

I have a 930k that when the implement pressure reach the 2.000psi (measured at the control valve), the machine inmediately stops working and that main pressure drops to 0. It is not an implement lockout switch problem, since we checked the tilt and lift solenoids and they keep working. Valve relief at the inlet manifold is new, valve relief at the oulet manifold is new. We made a lot of tests and always the machine gets blocked when the pressure rise up to 2.000psi.

Any help? Any Idea?

Thanks

 

[Deimos]

Hello

Write the serial number of the loader, and what is the operating time of the loader in engine hours?

 

[Helbert Fonseca]

Hello,

DYB00413, 12.000 HOURS approx.

 

[Cmark]

You need to check the load sensing pressure at the same time and compare it to pump discharge pressure. There should be a test fitting on the LS line at the implement pump end.

 

[Deimos]

Does the machine stop moving while implement stops working? After the machine is blocked and the pressure becomes = 0, do you need to shut it down and restart the machine to make everything work?
Have you checked the Dead Engine Lower valve?


Next is a recommendation in case the machine moves while implement does not work.
First, I would recommend you to check Low Pressure Standby, and check and adjust Margine Pressure.
If you say that the main pressure becomes = 0, then this is very bad. The main pressure cannot be very low and equal to zero. Implement Low Pressure Standby should be = 363 ± 44 psi and it should not fall below.
It is very likely that you have wear of the internal components of the implement hydraulic pump, or pump drive. And this is only a repair or replacement of the pump.
But still try to adjust Margine Pressure first, maybe this will give some effect.

 

[Deimos]

And while the implement pressure becomes zero, the pilot pressure needs to be measured.

 

[Helbert Fonseca]

Does the machine stop moving while implement stops working? After the machine is blocked and the pressure becomes = 0, do you need to shut it down and restart the machine to make everything work?
Have you checked the Dead Engine Lower valve?


Next is a recommendation in case the machine moves while implement does not work.
First, I would recommend you to check Low Pressure Standby, and check and adjust Margine Pressure.
If you say that the main pressure becomes = 0, then this is very bad. The main pressure cannot be very low and equal to zero. Implement Low Pressure Standby should be = 363 ± 44 psi and it should not fall below.
It is very likely that you have wear of the internal components of the implement hydraulic pump, or pump drive. And this is only a repair or replacement of the pump.
But still try to adjust Margine Pressure first, maybe this will give some effect.

Hello, sorry to just reply until now. Yes you were right, I had to change drum, pistons and valve plate of the implement pump.