i have a caterpillar 320C Excavator around 10 min working the swing motor suddenly stopped working. the hydraulic hose have pressure when i attempt to swing the machine but it was locked. the other hydraulics works it is only the swing left and right. after five to ten minutes rest the swing motor works again. i will appreciate any help you can give. thank you
I would check the standard swing brake solenoid, if you have an optional swing brake switch in the right side console, you can turn this on and it should bypass the standard swing brake.
The standard swing brake solenoid is located in the center on the pilot manifold and this is located under the main control valve.
You can swap it with the one right next to it, this is the travel speed solenoid and would one prevent two speed travel. The other side is the lockout solenoid and would stop all hydraulics. All three are the same part number.
If you have the optional swing brake release switch, the swing motor will have a solenoid mounted with the cross-over relief valves on the swing motor.
If the problem is in the ecm control, you can place the backup mode switch in the manual mode and the swing brake should release, if the solenoid and wiring is good.
thank you i will check the machine and the serial number of excavator is CAT0320CAGNG01086. in addition to the information after resting around 5 to10 minutes the swing motor works normally.
Yes, I saw that in your first post, that is why I think it is the solenoid. It is getting hot and fails, cools and will work again. Wires can do this too but, usually fail quicker and return quicker. A corroded connector can cause the same issue. If you wiggle wires and it begins to work again, open the connectors to check for corrode d pins. They will turn black when they get hot. A good solenoid will have 32.0 ohms resistance through it.
Here is a wiring drawing to help you identify the solenoids. It appears this model may have extra solenoids for the optional swing brake release (fine swing) on the same manifold under the main control valve.
Let me know if you need further assistance, I will be glad to help.
19 years Cat, 3 years Case