The hydraulic cylinder is the most important part of the hydraulic system of the concrete pump including the boom unfolding, the outrigger extension, the pumping system, and the swing of the S tube, all of which are inseparable from the driving of the hydraulic cylinder.
There are many types of hydraulic cylinders. Except for the plungers used in the early stage, the most common used on the concrete pump is the single piston rod hydraulic cylinder shown in the picture below. It has two ports A and B. When A is used as the pressure port, B is the return port; when B is used the pressure port, A is the return port. The piston is moved by the pressure oil in the cylinder to achieve the expansion and contraction of the piston rod and to unfold and fold the boom.

The pump boom is equipped with this type of hydraulic cylinder. And, the main cylinder of the pumping system also uses a single-piston rod hydraulic cylinder.
During the daily use of the concrete pump, the hydraulic cylinder easily gets problems. Because whether it is a boom cylinder, the main cylinder or a swing cylinder when the concrete pump is pumping, their working intensity is very high. The hydraulic cylinder also has a certain lifetime, and the seal inside the cylinder belongs to wear parts as well. Therefore, the cylinder will inevitably have various problems.

Here are some helpful tips to extend the lifetime of the cylinder.
1. Change hydraulic oil and seal regularly
The cleanliness of hydraulic oil is a key factor affecting the lifetime of the cylinder. If the hydraulic oil is not replaced for a long time, the iron filings and residue contained in the hydraulic oil will accelerate the wear speed of the sealing ring once it enters the cylinder. In worse cases, it is more likely to scratch the piston head or the oil rod.
2. Use qualified sealing rings
Common materials for O-shape sealing rings includes NBR, FPM, and SI, etc.. Different material has different features. Both physical and chemical performance is with big differences. Working temperature and pressure should also be considered for choosing sealing rings.
3. Protect the piston rod
The piston rod is smoothed by a chrome plating process, and used with seal rings. If the surface of the piston rod is damaged, it will directly cause the seal to be scratched and even cause foreign objects to enter the cylinder, causing more serious consequences. Therefore, when the pump boom is unfolded, it is necessary to observe the surroundings and whether there are obstacles to block the cylinder from working to prevent bumps.
4. Lubricate the jointed parts
The two ends of the cylinder are the bottom of the cylinder and the earrings, which can be connected with other structural parts or moving parts. The joint is generally mainly made of a pin, which needs lubrication during operation to prevent abnormal wear in the absence of oil. This can cause problems such as loose cylinder connections and even abnormal noise.
5. Give it a break
When the cylinder is not working, it is better to keep its natural states, such as the boom cylinder and the outrigger cylinder. When the concrete pump is not working, it is better to fold the boom and give the cylinder a break. Being under pressure for a long time will also reduce its lifetime.

Normally, the cost of repair and replacement of the cylinder is high for either a boom cylinder or a master cylinder. If you find that the damage to the cylinder is serious, you should directly choose to replace it with a new cylinder of the same type instead of repairing it to save money and save time.
Edited by Hello-Parts.com