When a hydraulic machine lacks power, often the first assumption people make is that the pump has a problem. Then, the typical procedure is to unmount the hydraulic pump and take it into a shop such as Bernell Hydraulics for troubleshooting with advanced testing gear.
While we are always happy to provide troubleshooting services, we don’t want you to have to go through the hassle of disconnecting all your hoses and removing your pump if it’s not really necessary. We advise you to try these 3 simple tests before removing your pump. They will take just about a minute to perform, and could potentially save you from hours spent disconnecting, transporting, and reconnecting a pump that is actually working just fine.
Grab the right tool—typically a pipe wrench—and give the shaft a couple of turns. Do you feel any jerky movements, excessive play, or vibration in the shaft? If so, it is almost guaranteed that the pump is the source of your system problem. The shaft rotation problems you have detected are common symptoms of serious failure of the rotary group or the bearings.
This test only works on a gear pump—sorry vane pump owners! Take a cloth and seal up the pump’s outlet. Then, take your air gun and blow compressed air into the pump’s inlet. If you find that a lot of air is passing out of the case drain port or suction port, this means there is an internal leak in the pump. The most likely cause of the leakage is serious damage to the rotary group. This easily confirms that you need to repair or replace your hydraulic pump.
One more test you can try in 60 seconds or less is to open up the case drain port and peer inside with a flashlight. If you see metal chips and shavings winking back at you, or detect other signs of wear on the component walls, you definitely have a pump problem.
Assuming your hydraulic pump is damaged, you can bring it into Bernell Hydraulics to see if a repair is possible. If not, or if a repair is possible but not cost-effective, we can help you order a new hydraulic pump. We carry a complete selection of Parker pumps as well as quality pumps from many other manufacturers.