By Todd Lewis
In a dump truck design, telescopic hydraulic cylinders include a series of steel tubes, referred to as stages, nested inside one another. Typically, a standard telescopic cylinder for a dump truck has between 2 and 5 stages. With this design, the cylinders allow for a longer extension stroke, unlike standard hydraulic cylinders, making them ideal for dump truck operations.
These truck hydraulics are moved when pressure is introduced, causing the largest tube to move, then subsequently each smaller tube. In the process of retracting the cylinder, the smallest tube will close first, up until the largest one. While this is a highly relied-upon system, it does require maintenance to ensure a well-running machine.
There are a number of issues that can arise with a hydraulic truck bed. With so many different elements to the design, troubleshooting dump truck hydraulics takes special expertise to find and solve the issue. To better understand potential dump truck telescopic cylinder issues, our telescopic cylinder repair team is breaking down the most common problems you will run into.
Wondering how to troubleshoot dump truck bed hydraulics in a truck that is vibrating? There are many scenarios to look into if the cylinder seems to chatter or vibrate, including:
There are many hydraulic cylinder repair needs in the case of a vibrating cylinder. If you cannot determine the cause on your own, turn to an expert for assistance.
For a tipper that won’t move, this may be a sign that the hydraulic fluid is low. However, there are a few other scenarios, such as a heavy load, a faulty pump, a faulty electric motor, or a dead battery that can cause the tipper to get stuck.
For this issue, you can:
If your dump truck bed raises slowly, you may have an issue with a weak battery, as well as loose battery cables or wires and other mechanical issues. In addition, this issue can be a sign of the tipper being overloaded.
Typically, the battery is the most common cause for this slow-lifting tipper. All that needs to be done to fix this is to charge the battery. If it won’t charge, that’s a sign that it’s dying. Do not continue trying to tip the truck on this kind of weak battery, however. This will cause a fuse to blow, leading to more costly damage. Instead, if your battery won't charge, try:
For an engine-powered system, this issue points to a pump problem. The issue could be linked to:
Hydraulic fluid for dump trucks should not be leaking, and if it does, it can become a significant issue. To look for leaks, operate the hydraulic system and look at all the hoses and pipes, valves, cylinder, and pump connections for signs of a leak. If you don’t see anything, look for other signs of damage on the surface of the hoses to see if the wire reinforcement has rusted. This rusting can be caused by a damaged hose cover, which causes oil to leak from the hose. This is common in situations where a hose was exposed to road salt spray.
Additionally, hydraulic leaks can be caused by other damaged components. If the pump isn’t running or the tipper isn’t operating as it should, a professional repair service may be required to further inspect the issue.
For a hydraulic dump bed stuck in up position, there are a few elements to troubleshoot in the system.
First, if your tipper is controlled by a solenoid valve, check to see if you can hear the valve click when it is switched to operate. If your system has an override button in the middle of the valve, press this to see if it will help the dipper descend. If this happens, this points to a burnt-out coil. You can further test this by seeing if it attracts a steel screwdriver since an energized coil is magnetic. If the coil becomes magnetic, then this is actually a sign of an issue with the valve, and won’t require a coil replacement.
On the other hand, if your machine is controlled by a manual or solenoid valve, the manual spool valve is likely stuck due to a broken linkage between the valve spool and the operating handle. That being said, there can also be other valves in the circuit in addition to the directional control that is broken or damaged. Pay special attention to any check valves and one-way restrictors, and see if any quick-release couplings are worn out. These couplings can get partially disconnected, causing issues with oil flow.
Another sign that hydraulic cylinder maintenance is needed is if the telescopic cylinder won’t come down completely. If you run into this, the first thing to look at is if there is anything mechanically holding the dump body up. Remove any obstructions under the body, following all safety guidelines, to ensure anything in the way of it coming down is removed.
Another cause of this dump truck hydraulic issue is if mechanical frictional force is getting in the way of it coming down. To solve this, look at the cylinder stage sleeve for straightness. A bent tube will cause this additional friction between the moving elements, and if it is not bent, it must be replaced.
If those aren’t the issues, look at what the pressure rate the system is running at. The pressure may have been too high, causing the cylinder to swell. When retracting, the swelled area will be forced to the larger stage, preventing it from fully retracting. Look at the sleeves for swelled arrears, and if you see any, replace the cylinder.
In addition to these issues, look at the reservoir air breather to ensure it’s not blocked. Additionally, check that the hydraulic components are working as they should and the cylinders with internal auto-bleed designs don’t have internal damage.
If you suspect a mis-staging issue with your truck hydraulics, take a look at:
Whether you're dealing with a hydraulic dump bed stuck in up position or a dump truck bed raises slow, there are several ways you can troubleshoot the situation to find the cause. While, in some cases, there can be some simple causes and solutions, the experts can ensure your dump truck hydraulic system gets back to fighting condition.
To avoid any further issues with your dump truck and ensure quality hydraulic cylinder maintenance, our telescopic cylinder repair company is here to help. For our expert insight, contact us online today to request our services.
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