Phenomenon: The steering gear is heavy.
Reasons: The steering system lacks hydraulic oil, or there is air in the oil circuit; the oil storage tank filter element is clogged or the filter screen is used for too long, and the oil outlet is blocked due to damage; the regulating valve on the oil pump does not work well; the booster piston The seal ring or the seal ring in the middle of the two radial seal ring grooves on the valve body is damaged; the spool valve is not good (the gap is too large or the closure is not strict); the check valve is not good (drain), etc. will cause steering heavy. The low pump pressure of the oil pump and the wear of the steering rod ball head, the poor lubrication of the steering knuckle main pin, will also cause heavy steering.
(1) Check whether the oil level of the hydraulic oil storage tank is too low and whether there is air in the oil. If the oil level is too low, hydraulic oil should be added to make the oil level reach the specified height of the dipstick. If there is air in the hydraulic oil, carefully check the hydraulic oil pump inlet pipe for cracks, cracks, and loose joints. After troubleshooting, the air in the hydraulic oil should be drained.
(2) Check whether the filter element in the oil storage tank is cracked or damaged. If it is damaged, it should be replaced with a new one. If it is dirty, it should be cleaned.
(3) Check whether the oil flow of the oil pump and the function of the safety adjustment valve are good. The method of inspection is as follows:
Install a pressure gauge C and valve D with a range of 150 bar on the high-pressure oil pipes of the steering oil pump and steering gear. Open the valve, start the engine at idle speed, and close the pressure gauge for about 5 seconds for a short time (the time cannot be long to prevent the oil pump from overheating and damage). Observe the pressure gauge. If the pressure gauge reaches 130bar, it will not continue to rise, indicating that the steering hydraulic pump is working normally ; If it is higher than 130bar, the safety valve is inaccurate, and it should be adjusted to 130bar; if the pressure gauge pressure is lower than 130bar, it indicates that the steering hydraulic pump is worn and has internal leakage, and the flow control valve and safety valve are not adjusted properly, and should be readjusted. If the adjustment fails to meet the requirements, the steering hydraulic pump should be replaced.
(4) Check the spool valve to see if it works well. If the closing is not tight due to excessive clearance, a new steering screw and spool valve should be replaced.
(5) Check whether the sealing ring on the booster piston and the intermediate sealing ring in the radial ring groove of the valve chamber body are in good condition. Replace with new ones if necessary. At the same time, check the surface of the cylinder for damage.
(6) Check whether the ball and seat of the one-way valve are sealed, if the closing is not tight due to the dirt, it should be thoroughly cleaned; if the valve body itself causes the tight closing, it should be replaced with a new one.
(7) Check the use and lubrication of the ball pin of the horizontal tie rod. If the wear is serious, it should be replaced.
(8) Check the lubrication of the knuckle kingpin and bushing. Due to poor lubrication, it will corrode and cause steering difficulties.