1、 Conventional oil change of steering system:
1. The steering hydraulic system is composed of power steering gear, oil pump, oil tank, oil pipe and oil pipe joint, etc. The cleanness of the steering hydraulic system must be strictly guaranteed so that the power steering system can work normally for a long time.
2. The oil inlet and outlet of the power steering gear cannot be connected reversely. The mark "P" or "(inward) ↑" indicates the oil inlet, and the mark "R" or "(outward) ↓" indicates the oil return port. The oil inlet of the steering gear is connected to the oil outlet pipe of the oil pump, and the oil return port of the steering gear is directly connected to the oil tank.
3. The power steering system is recommended to use 8 # hydraulic transmission oil, or 32 # anti-wear hydraulic oil, or similar oils such as ATF, DEXRON and GM series. The oil must be clean.
4. Only one of the above fluids can be added into the power steering system. Any mixed oil and unapproved fluid will damage and leak the oil seal, leading to a loss of steering assistance.
5. The hydraulic oil and oil tank filter element must be replaced when the new steering gear is driven for nearly 5000km. The hydraulic oil and oil tank filter element must be replaced after every 24000km or when the oil deteriorates. The air must be discharged after the oil is replaced.
6. The exhaust method is as follows:
① Inject the oil to the specified level of the oil tank;
② Start the engine and run it at idle speed (600~750r/min) for more than 30s. Meanwhile, check the oil tank level and constantly replenish oil to the oil tank;
③ When the engine is idling, turn the steering wheel left and right to the limit position (stay at the limit position for no more than 10s to prevent the oil pump from heating, repeat for 3~5 times, and check the oil tank level and constantly replenish the oil tank;
④ For the power steering gear assembly with bleed screw, loosen the bleed screw in the steering gear until the whole system is filled with oil, no bubbles emerge from the bleed port, and the liquid level in the oil tank no longer drops. Then tighten the bleed screw;
⑤ When the accelerator is increased (1500~2500r/min), turn the steering wheel left and right to the limit position (stay at the limit position for no more than 10s to prevent the oil pump from heating), repeat for 3~5 times, check the oil tank level at the same time, and constantly add oil to the oil tank until it reaches the level specified by the oil dipstick;
⑥ At this point, the steering force of the steering wheel is normal.
When refueling the steering system, do not turn the steering wheel during steps 1 and 2 above, otherwise air will enter the system.When changing the steering gear oil, drain the oil from the inlet and outlet, and do not remove any screws on the steering gear to drain the oil.When the steering wheel is turned to the limit position, the dwell time shall not exceed 10s, otherwise the oil temperature will rise sharply, causing damage to the steering oil pump, steering system seal, etc.
2、 Routine inspection of steering system:
1. Linkage of steering control mechanism: check the steering wheel, steering column or steering transmission device for interference, jamming, insufficient lubrication, flexible rotation, wear, looseness or damage, such as friction of the steering column or friction between steering transmission device and the outer cover;
2. Linkage of steering transmission mechanism: check the ball pin joints of steering pitman arm, horizontal tie rod, etc. for deformation, interference, jamming, insufficient lubrication, flexible rotation, wear, looseness or damage, such as the ball pin is not blocked by lubrication;
3. Limit angle position status: whether there is steering dead point (angle), whether there is interference between pull rod and tire or leaf spring;
4. Wheels and tires: whether the tire pressure is unequal from left to right, or whether the wheels and tires are worn seriously and unevenly (unilateral wear is serious);
5. Steering oil tank condition: whether the oil tank level reaches the correct level;Whether the liquid level of the oil tank rises or drops obviously and whether air is inhaled when turning or not;Whether the filter paper of oil tank is melted;
6. Hydraulic oil: check whether the hydraulic oil is dirty or deteriorated. Visually check whether the hydraulic oil is clear and transparent, and touch the hydraulic oil to see if it is free of impurities such as iron chips;
7. Oil pipe and oil pipe joint: whether the oil tank outlet pipe joint and high-pressure oil pipe joint are loose and "wet";Whether the sealing gasket is damaged;
8. Front axle kingpin: jack up the front axle, manually pull the tire to rotate left and right, and check whether the front axle kingpin is rusted, or whether the kingpin plane bearing is rusted, cracked or stuck;
9. Status of other relevant parts: whether the shock absorber is damaged, leaking oil, or whether the front suspension spring is deformed;Whether the wheel balance lead is not in place or dropped;The level of frame or airbag is inconsistent;Whether the front axle shaft bearing fits too tightly;Whether the front wheel alignment angle is reasonable;Whether the toe-in of front wheel is too large and so on.
10. Repair and replacement: if the steering system parts have been repaired and replaced, check whether the pressure and flow of the oil pump meet the requirements;Whether the inlet and outlet oil lines are installed incorrectly;Whether the sealing gasket is replaced;Whether the diameter of oil pipe is too small;Whether the pipeline is constrained; Whether the graduation line of steering pitman arm and steering gear output shaft is aligned;Whether all screws, threads, joints, etc. are tightened;Whether the steering gear assembly is in the middle position when the tire is running in a straight line;Whether the liquid level of the oil tank reaches the correct level, and whether the liquid level rises or drops significantly when turning and so on.
3.Free clearance adjustment of steering gear (adjustment shall be carried out by professionals):
When the steering wheel idle travel angle exceeds the requirements of the whole vehicle, it is necessary to adjust the free clearance of the steering system.Turn the steering wheel back and forth from left to right at a small angle. When there is no response at the output end of the steering gear, it is necessary to adjust the free clearance of the steering gear;Turn the steering wheel back and forth from left to right at a small angle. Visually check that the output end of the steering gear is responsive. If the steering tire is unresponsive, adjust the free clearance of the ball pin at the pitman arm, horizontal tie rod, knuckle arm, etc.
Adjustment method for free clearance of steering gear assembly: ensure that the whole vehicle is in the middle position, disconnect the steering gear input and output connections, loosen the side cover locknut by about 2~3 turns with a fork wrench, and then turn the side cover adjusting screw clockwise to the point where it cannot be turned, and then back the side cover adjusting screw by about 1/6 turn, and turn the input end with a fork,Confirm that the output shaft follows when the input shaft of the steering gear rotates and the steering is flexible.Fix the adjusting screw of the side cover with a straight start, and tighten the lock nut of the side cover with a fork wrench to ensure that the tightening torque reaches 70~80 N.m.Turn the input shaft with the yoke again, and confirm that the output shaft follows when the steering gear input shaft rotates, and the steering is flexible.When the free clearance is adjusted too much (the adjusting screw of the side cover is screwed in too much), the steering gear can not be returned in time when turning the wheel, and may be stuck.The free clearance adjustment of steering gear assembly shall be carried out by professionals.
1. Clearance adjustment of other parts of the steering system: the system clearance is mainly from the ball pin, and only the faulty parts can be replaced when the system has clearance.
4、 Replacement of steering gear:
1. Clean the whole pipeline and oil storage tank before replacement to ensure that there is no residue left.
2. Install the dust boot that comes with the steering gear correctly.
3. Oil inlet and outlet shall not be connected reversely.
4. Exhaust the steering hydraulic system after replacement.