During operating the bulldozer, may bulldozer operators will face some problem. For example, the shantui bulldozer can not be start.
1. bulldozer Cannot start
The bulldozer was unable to start during the unsealing of the hangar.
After eliminating the situation of no electricity, no fuel, loose or blocked fuel tank joints, etc., it was finally suspected that the PT fuel pump was malfunctioning. Check the air and fuel control device. don’t simply change the bulldozer parts , After opening the intake pipe and using an air compressor to supply air to the intake pipe, the machine can start smoothly. If the air supply is stopped, the machine will immediately turn off. Therefore, it is determined that the air and fuel control device is malfunctioning.
Loosen the bulldozer fuel control device fixing nut, turn the AFC fuel control device clockwise with an Allen wrench, and then tighten the fixing nut. When the machine is restarted, it can start normally and the fault disappears.
2. Failure of fuel supply systems
The bulldozer needs to be driven out of the hangar during a seasonal maintenance, but it cannot be driven.
Check the fuel tank, the fuel is sufficient; turn on the switch at the lower part of the fuel tank, and it will automatically turn off after 1 minute of driving; use the filter inlet pipe to directly connect the fuel tank to the fuel pipe of the PT pump. ; Tighten the manual screw of the oil cut solenoid valve to the open position, but it still cannot be started.
When installing the re-filter, turn the fuel tank switch 3~5 turns, and find a small amount of fuel flowing out of the fuel tank filter inlet pipe, but the fuel will run out after a while. After careful observation and repeated comparison, it was finally found that the fuel tank switch was not turned on. The switch has a spherical structure. When it is turned 90°, the oil circuit is connected, and when it is turned 90°, the oil circuit is cut off. The ball valve switch has no handle and no limit device, but the square iron head is exposed. The driver mistakenly used the ball valve switch as a throttle switch. After turning 3 to 5 turns, the ball valve returned to the closed position. During the rotation of the ball valve, although a small amount of fuel enters the fuel circuit, it can only be driven for 1 minute. When the fuel in the pipeline is exhausted, the machine will turn off.
3. Oil leakage from winch
During the construction of the bulldozer, oil leakage occurred at the wire rope winch. After pulling out all the wire ropes, it was found that the hydraulic oil leaked from the bolts on the winch seat, and when the throttle was increased, the leak was faster, and there was almost no oil leaking when idling.
Preliminary analysis may be caused by loose bolts or damaged gaskets, but after replacing the gaskets and tightening the bolts, test the machine, the fault remains. Further analysis of the hydraulic schematic diagram suggests that the reason may be poor oil return and large back pressure. Therefore, the oil return pipe from the winch to the control valve was replaced, that is, a short oil return pipe was welded to the upper part of the inside of the fuel tank, and replaced with a hose that was thicker than the original oil return pipe so that the end of the oil return pipe was not connected to the control valve. Directly connect the new oil return short pipe to reduce the oil return back pressure. Try the machine again and the fault disappears.
4. The heat engine can’t walk
During use, the cold machine started and bulldozing were normal, but after 50 minutes of work, the bulldozer became weaker and weaker as the oil temperature gradually increased, and it was even difficult to walk under no load. If you stop and rest for 2 hours at this time, start the engine again after the oil temperature drops, and the start and bulldozing will return to normal.
During the operation, the engine throttle did not decrease and the speed did not decrease, indicating that the bulldozer’s weakness has nothing to do with the engine. Preliminary analysis believes that the cause is the lack of oil in the bulldozer torque converter, the blockage of the oil circuit or the failure of the transmission or steering clutch.
Check that the torque converter is normal; loosen the vent screw on the variable speed fine filter, and it is found that there are bubbles in the discharged oil, which can not be exhausted for a long time. The analysis believes that if there is a place where air enters, both the cooler and the warmer should be aired, causing the machine to work normally in the cold state, and it can be concluded that the low-pressure oil circuit is in good condition. The air intake of the high-pressure oil circuit of the heat engine causes the machine to fail to walk, which should be caused by the excessive vacuum of the low-pressure oil circuit.
5. Shantui Bulldozer Blade does not run
After starting the engine, the control device and the bulldozing blade did not respond. Check the hydraulic oil tank and find that the oil tank is empty. According to the driver, the hydraulic oil tank was filled up before leaving work the day before yesterday. Therefore, the engine oil pan was checked and the oil level was found to rise. Then the working oil pump was removed for inspection, and it was found that the rotating oil seal of the working oil pump was damaged. The hydraulic oil tank is located at a higher position, allowing the oil to penetrate into the oil pan of the diesel engine through the damaged rotating oil seal in one night. In the face of this situation, replace the new oil seal and engine oil, add hydraulic oil, and drain all the air in the hydraulic system so that the bulldozer can operate normally.
6. Unable to start the diesel engine
The filter element of the engine fuel filter is blocked or the fuel line is blocked. In this case, the fuel filter element must be cleaned or replaced with a new one, and the fuel line must be cleaned at the same time.
There is fuel in the cylinder. Check the fuel level in the diesel tank. If the fuel is not enough, add fuel, clean the fuel injection nozzle or replace with a new one.
7. The gearbox cannot be engaged in a certain gear
The seal ring of a row of pistons of the gearbox is damaged, and the end face of a row of planetary gears is damaged. If this is true, replace the end pad or seal ring with a new one.
The gearbox lever system is not adjusted properly or is loose. Faced with such a situation, it is necessary to re-adjust the gearbox lever system.
8. Prevent Shantui Bulldozer Chain from wearing
The tension of the chain will affect the sliding, pressure and friction between the components of the bulldozer’s running mechanism. Only when the chain tension is moderate can the wear of the walking mechanism be reduced and the chain derailment can be avoided. Therefore, the tightness of the chain and Shantui Bulldozer Roller , Shantui Dozer Front Idleris extremely important. The tension of the bulldozer chain is too large, which increases the pressure and friction between the relative moving parts of the walking mechanism, and the friction increases, the sound produced by it is sharp and harsh, which intensifies wear. Especially the welded chain and wheel, the welded surface is not smooth, causing the contact surface between the parts to decrease significantly, so that the wear can be increased, which causes the roller welding layer and the chain link to peel off. . The above-listed phenomena can also cause parts to heat up due to wear, and eventually lead to premature failure of the seals of each part and damage to the parts.
Post time: Oct-28-2021