The presence of air in the vehicle's hydraulic system is often the main cause of failure in the system and is easily overlooked. If the air in the system has indeed been removed, the fault still exists and can be inspected, diagnosed and repaired as follows.
1 The reason for the heavy steering and its repair (1) The hydraulic system has air infiltration. Check if the oil inlet pipe joint from the fuel tank to the hydraulic pump is loose or broken. Is the gasket of the hydraulic pump suction seal sealed? Is the taper joint surface of the oil pipe joint and the hydraulic pump or the tank joint tight? The seal of the hydraulic pump drive shaft and the seal ring is reliable. After the cause is identified, measures to block the infiltration of air into the system are taken and the air in the system is excluded.
(2) The hydraulic system has insufficient oil. It may be that the system oil leakage pipe joint is loose or the oil pipe is broken, and the clearance between the grinding pump and the bearing is too large, so that the hydraulic oil leaks into the engine oil sump. After removing the leaking fault, add enough hydraulic oil.
(3) The hydraulic pump itself has insufficient oil supply pressure or insufficient oil flow. Disassemble the hydraulic pump, replace worn parts, and replace the new hydraulic pump if necessary.
(4) The filter is clogged. The filter element should be cleaned or replaced.
(5) The pipe joint or pipe is clogged with dirt. Unblock it.
(6) The rack and the toothed fan have an improper meshing gap. An adjustment screw on the left side of the housing can be used to adjust the axial displacement of the shaft. When adjusting, first place the steering wheel in the middle position, loosen the lock nut, tighten the adjusting screw and then rotate it for 5/6 weeks to ensure the correct transmission clearance of the rack and the toothed fan.
(7) The axial clearance of the steering shaft is too small. The adjustment method is to loosen the fixed bushing and the M8 fixing screw, use a special hook wrench to screw the adjusting nut to the end and then loosen it for 1/8 turn, then tighten the lock nut and the M8 screw.
(8) The safety valve is not tight or the spring is too soft to cause internal leakage, resulting in insufficient pressure. The safety seat and ball valve should be inspected for pitting, missing or excessive wear. Check if the safety valve spring is broken or the spring force is insufficient. Repair or replace parts as appropriate.
(9) The hydraulic oil used is not the right brand or the performance is not good. Hydraulic power steering gears require high physical and chemical properties such as viscosity of hydraulic oil. This type of steering machine requires OT H3 hydraulic oil. The viscosity of Enshi is 3~4 at 50 °C. It can be replaced by domestic hydraulic oil of the same performance (such as No. 20 hydraulic oil), but it is not allowed to mix two different oils. In addition, the hydraulic oil must also have the following characteristics: no moisture and impurities, no foam, good lubricity and viscosity temperature, no water-soluble acid and alkali, good chemical stability, etc. If the substitute is used indiscriminately, the seal will be damaged prematurely, and the movements will wear out early, causing the hydraulic system to work worse or even fail.
(10) The seal of the hydraulic pump, power cylinder or related parts is damaged, causing leakage of hydraulic oil. The oil leakage seal should be replaced.
(11) The control valve (spool valve) is worn out too much. The precision of the valve core and the valve body is very high, and the gap is 0.01 mm. If the wear is too large, the leakage increases, the steering lag time is prolonged, the sensitivity is poor, and the steering wheel is heavy. In this case, the spool can be replaced.
(12) The power cylinder and piston are worn seriously or the surface is rough. Since the impurity particles in the hydraulic oil cause the mating surface of the piston and the power cylinder to be pulled and worn, the oil leakage pressure is also caused. If the fit clearance exceeds 0.15 mm, a new corresponding size piston must be replaced. In the use, pay attention to the filtration work during refueling, and do not allow the foreign particles to mix into the hydraulic system. When repairing, pay attention to the piston and the hydraulic cylinder, the slide valve and the valve body are not interchangeable at random.
(13) The steering gear housing is deformed due to the collision.
(14) Insufficient air pressure on the front tire, damage to the knuckle kingpin thrust bearing, and incorrect front wheel positioning can also cause heavy steering, and it is a factor that cannot be ignored.
2When the steering is light and heavy, the reason and repair (1) The spool valve is not in the middle position of the valve body, or the manufacturing position is in the middle position, but the left and right shoulder gaps are not equal. At this point, the spool should be replaced.
â—‹ Common faults and troubleshooting methods for auto power steering gears of Heji Fan Clinic in Xiying Education Center, Shihezi City, Xinjiang. Skoda type (2) The spring tension of the positioning springs at both ends of the slide valve is inconsistent. It should be replaced with a new spring of the same length and elasticity.
(3) There is dirt in the valve body, so that the reaction plunger is stuck, or the small hole of 0.9 is blocked, so that the pressure oil flow cannot flow smoothly. The small holes should be unblocked to remove the attached dirt so that the plunger can slide smoothly.
(4) If the piston stroke end buffer valve is improperly adjusted, the piston will pass the stroke limit position, and the high pressure chamber cannot be unloaded in time. This should be adjusted.
(5) The safety valve seat has impurities or steel ball wear, and sometimes it is well sealed and sometimes cannot be sealed. The safety valve should be repaired or replaced.
(6) The performance of the sealing ring is deteriorated, and the sealing is good or bad. The seal should be replaced in time.
3 After the vehicle turns back, the main cause of this phenomenon in the hydraulic system is the presence of air in the hydraulic circuit. The air should be drained in time, especially the air in the slide valve.
4 The vehicle can't keep the straight line while driving. The vehicle can't keep the straight line. There are several reasons for this: (1) Two small holes with a diameter of 0.9 mm on the control valve sleeve, one of which is blocked.
(2) The spring at both ends of the slide valve is too soft or damaged, or the slide valve is stuck by impurities and burrs. The reverse transmission resistance of the steering gear cannot be overcome, and the slide valve cannot be returned in time, resulting in a pressure difference between the upper and lower chambers of the piston, forcing the front guide. The wheel is deflected to one side.
(3) The flow rate of the hydraulic pump is too large, making the steering too sensitive.
(4) The front wheel is out of alignment, the front axle is not installed correctly, the left and right wheel air pressures are inconsistent, or one front wheel is often in a partial braking state, which also causes the vehicle to be unable to travel straight.
Inspection method: Check the cleaning slide valve to remove the dirt in the small hole of 0.9mm. Check the positioning spring. If the elastic force is insufficient or broken, it should be replaced. Check the hydraulic pump oil pressure. If there is any problem, it should be repaired and corrected. Correct the front wheel positioning. If the front axle should be deformed or installed incorrectly, the front wheel pressure should be repaired or reassembled. The brakes should be consistent with the brakes. The brakes on the wheels should be consistent. The cause should be identified and eliminated in time.
Skoda hydraulic resistance steering gear has complex structure and many troubles, but if you are familiar with its structure, understand the working principle of hydraulic system, master the fault symptoms and causes, and then according to the measured hydraulic pump hydraulic pressure, flow and other data, from easy to Difficult, from the table and inside, you can quickly and accurately determine the cause of the fault and the location of the fault, and quickly eliminate it.
In the face of the high fuel prices and the fuel tax date, how to save fuel has become a problem that people think strongly.
There are many measures to save fuel, but in the face of a specific car, users can only start from its use and maintenance, in order to achieve fuel-saving purposes.
1 In the reasonable use of the car, the warm-up time before the fuel-saving driving should not be too long. Once the idle speed is stable, it can start, and the acceleration should be accelerated at the start.
After the vehicle starts, the engine should be shifted when the torque of the engine reaches the maximum. If it is too early, it will cause the cylinder to knock. Too late, it will cause a waste of torque. Both of these situations are not conducive to fuel economy.
While the vehicle is in the process of running, some speeds can be used in both higher gears and lower gears, and should be hung up in a higher gear in time to make the car run at an economic speed close to each gear.
When encountering a situation where parking is required, emergency braking should be avoided as much as possible. At this time, the acceleration-sliding driving method can be reasonably used, because at the same average speed, the acceleration gliding is more fuel efficient than the constant speed driving. However, when accelerating the driving, the carburetor enrichment device should not be used for work. At the same time, the engine should not be turned off when coasting, otherwise it is not conducive to the safe and reliable braking of the car with pneumatic brake and vacuum afterburner.
2 In the correct maintenance of the car, fuel-saving, regular inspection, adjustment and cleaning of the carburetor to provide the ideal mixture of components, thereby improving the fuel economy of the car.
The air pressure of the tire should be kept near the standard value. If the tire pressure is reduced by 30, when the car is driving at 40km/h, the fuel consumption of the car is increased by 5 to 10, and the fuel consumption of the diesel truck is increased by 20 to 25. However, when the tire pressure is too high. It will also increase the wear of the tires.
Maintain normal engine water temperature and oil temperature. Generally, when the water temperature is 80-90 °C, it is beneficial to reduce fuel consumption. If the water temperature is too high, the combustion may be abnormal, resulting in a decrease in engine power. If the fuel consumption is too low, the cooling loss will increase. When the viscosity of the oil is too high, the resistance of the movement of the machine increases, which in turn increases fuel consumption.
Correct adjustment of bearing and oil seal tightness and normal lubrication can greatly improve the efficiency of the drive train and reduce fuel consumption.
There are many ways to save fuel. I believe that drivers and friends will find more and more fuel-saving ways in the specific operation, and then calmly face the changes in the fuel world.
How to do the fuel in the outpatient car, how to do it?
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