In true AC electric coils, the resistance or impedance of the coil is lowest when the solenoid is open, i.e. when the plunger is out. Impedance increases as the plunger is pulled into the closed position. As a result, the current draw of an AC solenoid is highest when the solenoid is open (plunger out) and lowest when the solenoid … Read more
The hydraulic pump is the hardest working component of a hydraulic system. And as the pump wears in service, internal leakage increases and therefore the percentage of output flow available to do useful work (volumetric efficiency) decreases. If volumetric efficiency falls below a level considered acceptable for the application, the pump will need to be changed-out. In a condition-based maintenance … Read more
Jason from California (not his real name) wrote me this:
“Brendan, I wanted to share with you a troubleshooting story and how your techniques helped save my service department $15,000.
We recently did a complete tear down and rebuild of a CAT 988H wheel loader. After many months the project was completed and the machine shipped to the customer. A … Read more