How to Test Main Hydraulic Pump on a Used Concrete Pump
At JED Alliance, before we place a used concrete pump for sale, our team does a leak-down test.
In fact, we always fully inspect any used heavy equipment that we restore in our shop for worn and non-working parts, and repair them. The reason it is so important to inspect the hydraulic pump on each trailer concrete pump is to ensure it can hold the pressure necessary to pump any job. Since we have a lot of experience with testing the main hydraulic pump, I want to share how to do it in the video below.
Detailed instructions are included below the video.
Prepare Used Concrete Pump for Testing
Turn on your pump and open up the side panel. There you will see the S1 and S2 control blocks. One controls the rock valve and the other activates the soft/hard stroke. They each have a quarter-turn valve. When you turn the S1 to the closed position, it locks the rock valve causing the machine to build pressure. Turning the S2 the same direction activates the hard stroke ON. This will help you achieve pressure of 300 BAR.
Perform the Hydraulic Pump Test
Follow these steps to test the main hydraulic pump of your trailered concrete pump:
- After locking the whole system using the control block valves, rev the engine and hit “pump forward”.
- Look into the water box to make sure the differential cylinders are not moving. The pump’s gauge will achieve the 300 BAR.
- Then decelerate the engine gradually all the way down.
- Look at the main hydraulic gauge. It should not drop more than 35 BAR of pressure.
- After testing, place the pump in neutral and do a half of stroke in reverse. this allows the pressure on both circuits S1 and S2 to be relieved. Once the pressure is relieved, the quarter-turn valves will turn easily.
- Stop the pump and unlock the valves, so your trailer concrete pump is ready to work next morning.
What you are trying to do with this test is to achieve volume and not pressure. So without the engine running at full throttle, the pump has to work twice as hard to maintain the same pressure. If your used concrete pump test shows that the pressure drops by more than 35 BAR, then it is time to do some maintenance to ensure you have no costly breakdowns during a job.
What are your tips for keeping your concrete pump’s hydraulics in top condition? Share in comments below.
