| A PD220-type bulldozer, in the process of bulldozing | | | | bulldozers are still weak. Therefore suspected to be |
| roadbed earthwork weak. The site inspection revealed | | | | due to wear and tear caused by the core Pressure |
| that the normal engine power, transmission and torque | | | | Regulating Valve with lower pressure. In the relief |
| converter than the dirty filter, hydraulic oil deterioration, it | | | | valve were opened, we found in the inlet Department |
| is estimated that the resulting failures. Therefore, they | | | | has two rubber pads stuck to spool so that the relief |
| removed a magnetic coarse filter cleaning, filter and oil | | | | valve does not work, therefore can not ensure that all |
| filter 3 in the hydraulic oil and transmission replaced | | | | gear clutch engagement, resulting in earth-moving |
| along with, but the bulldozers are unable to work a | | | | weak. After the rubber pad cleared, bulldozers working |
| few hours later. | | | | back to normal. |
| As the mechanic at the scene this failure can not be | | | | In analyzing the sources of rubber pad in the oil filter |
| ruled out, then the machine will be shipped back to the | | | | also found inside the three have the same rubber pad, |
| company machine repair shop for repairs. I measured | | | | but also with relief valve mouth of the rubber pad can |
| from the C transmission clutch pressure 2.0MP (normal | | | | be makes up a complete gasket to prove that the |
| pressure should be 2.5MPa), due to low pressure, | | | | rubber gasket from the old entered on the aging filter |
| variable-speed pump subsequently suspected of | | | | off the oil Road. This reminds machine repair personnel, |
| serious wear and tear, reaching less than a rated | | | | that is, when the repair operations must carefully |
| pumping pressure. In the new variable-speed pump | | | | check and not allow damage to residual material falls |
| replaced after the re-test machine and found that | | | | on the body. |