When a Xuangong TY165B bulldozer was working, it was found that the oil temperature of the hydraulic pitch changer rose rapidly. The operator has rich experience. Stop it immediately and check the following parts carefully.

　　1: Check the oil level of the transmission, the oil level is displayed normally.

　　2: Check the oil temperature gauge, it also shows normal.

　　3: Use a pressure gauge to test the pressure of the transmission regulating safety valve, the hydraulic torque converter inlet safety valve, the hydraulic torque converter outlet safety valve, and the hydraulic torque converter outlet regulating valve. All show normal.

　　Treatment method: remove the variable-pitch safety valve, check that the valve core is stuck, clean and reassemble the test machine, the oil temperature of the torque converter returns to normal