Genie-S125-hydraulic system-no steering and telescopic leg movement, no alarm

1. Case developer

Summer climb
Working number 80001850
Wuhan West Lake Business Store

2. Vehicle information registration

1. Manufacturer: Genie
2. Model: S125
3. Serial number: S12515D-1271
4. Number of working hours: 3732 H
5. Failure code: None
6. Failure system: hydraulic system
7. Failure phenomenon: The equipment does not alarm for steering and telescopic legs without action

 

3. fault phenomenon confirmation

After the equipment operation was ready to transfer to other places, the workers' response suddenly could not turn. When they arrived at the scene, they could not turn off and did not report to the alarm. Then they tested other actions to find that there were no legs and other actions.

4. analysis of the cause

1. Determine as an electrical failure: the handle steering key is damaged, the electrical turning is connected, and the DCON failure.
2. It is judged as a hydraulic failure: the overflow valve aging, the electromagnetic valve core card plug and the internal wear of the valve core.

5. Check and repair steps

1. Check the "LCD display"

Checking process: Check the status of the device through the display screen. At this time, the display screen is displayed normally without any fault prompts.

Judgment results: The device may be a short -term failure or hydraulic system failure, and the system module does not make effective failure records.

2. The analysis may be the problem of the handle, resulting in the instructions that have not been issued

Inspection process: The test of the test car of the same type of device handle on the spot was not resolved.

Judgment results: The steering function of the handle is normal, not caused by the handle.

3. Check the external control line of the solenoid valve: (use tool: universal table)

Checking process: Directly measure the load circuit terminal. By checking the electrical schematic diagram, the "universal table" tool DC mode is used to operate the "V36RRS-BL" and "VLVret2-BR", "V37RRS-BL/BK" and "VLVRET2-" BR ", and the other six groups to turn to both ends of the power supply of the solenoid valve coil, whether there is a voltage output.

The judgment results: The "universal table" was measured as DC13.7V, and the output of the system board card output to the coil load end was normal. Exclude electrical reasons such as intermediate electrons, DCON faults.


4. Check the related valve group of the hydraulic circuit: (use tool: block)

Checking process:

a) Disassembled to the tank oil pipe joint. It was found that no oil came out when operating the equipment. The solenoid valve was working normally but no oil came.


b) By analyzing the hydraulic drawing, the AA direction valve of the function valve block is provided with the fuel supply to the four -wheel turning valve block. Remove the valve core, clean and check without stagnation, no abnormalities, and the failure of the installation is not lifted.


c) According to the drawing further analysis, after the oil comes out of the AA valve, the central rotation connector is available, and then the four -wheel steering valve block is passed through the EP differential pressure valve, and then the function valve is turned to the steering. Remove the EP valve and find that the card stagnation is severe, causing high pressure oil to return to the fuel tank directly. Clean the EP valve, and use the inner hexagonal to confirm that there is no card lag backward, and the trial failure is lifted.


Judgment results: Through the above actions, the failure has been confirmed that the EP valve card stagnation causes the high pressure oil to the four -wheel steering valve block directly back to the fuel tank, so that no steering and telescopic leg function

5. Final failure point and solution: Through the above analysis and investigation, the failure phenomenon is determined as the stagnation of the EP valve card, which causes the high -pressure oil to the four -wheel steering valve block directly back to the fuel tank, so that no steering and telescopic leg function, cleaning the EP valve, cleaning the EP valve. Confirm that the cardless stagnation returns, the fault is lifted.

 

6. Summary of experience and refinement

1. Summary of experience: Repair equipment is preferred to judge the direction of electrical directions (required commonly used tools such as universal tables, electric pens, etc.). It is prompted to further confirm whether the electrical component is normal for power supply; after the above investigation, the failure is not eliminated before the mechanical direction is tested (a common tool hydraulic table, a dedicated spanner, a block, etc.), the hydraulic failure must be the function of the hydraulic principle drawings and various hydraulic components. There is a certain understanding. For multi -functional integration valve groups, the position and number of the component on the maintenance manual must be carefully checked in order to achieve the correct measurement and judgment.

2. Skills harvest: The principle diagram of the electrical and hydraulic system must be familiar. Using appropriate tools and correct maintenance ideas to improve efficiency. Due to the concealment, diversity, and causes of hydraulic system faults, failure to judge not only need to combine theoretical knowledge and sufficient maintenance experience during maintenance, but also equipped with professional pressure measurement tools. Endemication and improvement of work efficiency.