Troubleshooting Chart
Today we are going to introduce how to Troubleshooting Hydrostatic Steering System
For a number of years produce and export hydrostatic steering unit, our hydrostatic steering unit (Hydraulic steering unit, hydrostatic steering, orbitrol steering valve, are terms for what we call orbitrol steering unit ) are designed for low speed vehicles to replace Danfoss, and more origional steering unit you may find on origional large equipment, such as forklifts, tractors, loaders, mowers, fishing boats, construction equipment, aircraft ground support vehicles, mining and earthmoving equipment.
These hydrostatic steering units allow vehicles to be steered without mechanical connections.
In built valve options such as relief valves, check valve, shock valves, plus load sensing circuits are available. Thus making a compact steering unit & reducing the need for additional hydraulic components in the system.
| Troubleshooting Chart | ||
| PROBLEM | CAUSE | REMEDY |
| Heavy turning of wheel. | 1. Insufficient oil pressure or no oil | 1 |
| pressure at all. | a. Make the pump operate. | |
| a. Pump not operating | b. Repair or replace the pump | |
| . | . | |
| b. Pump defective. | c. Alter direction of pump rotation. | |
| c. Incorrect pump rotation. | d. Replace the pump | |
| d. Pump worn. | . | |
| 2. Relief valve sticking when open or | 2. Repair, clean and reset the relief | |
| the valve pressure is too low. | valve. | |
| 3. Blocked LS orifice or dirt particles | 3. Remove and clean the whole system. | |
| delaying spool movement in flow | Change all filter elements. | |
| amplifier. | 4. Contact your dealer for help under | |
| 4. Very high implement system | these special circumstances. | |
| pressures acting on EF port. | 5. Dismantle steering unit and reposition | |
| 5. Misplaced anti | or replace anti | |
| - | - | |
| cavitation ball in | cavitation ball. | |
| steering unit. | ||
| “Motoring” – steering wheel turning by itself. |
1. Leaf springs have sagged and thus | 1. Replace leaf springs in control unit. |
| have reduced elasticity or no | 2. Contact your dealer. In the meantime, | |
| elasticity at all (broken springs or | lower the relief valve setting | |
| otherwise) | . | |
| . | ||
| 2. Squeezed spool/sleeve. Possible | ||
| insufficient spool/sleeve clearance | ||
| Repeated steering wheel corrections required. Impossible to make steering go to neutral position. Steering to left or right on own accord. |
1. Leaf springs without elasticity or | 1. Replace leaf springs in control unit. |
| broken. | 2. Align steering column with steering | |
| 2. Steering column out of alignment | unit. | |
| with steering unit. | 3. Adjust the clearance. | |
| 3. Insufficient clearance between | ||
| steering column and coupling | ||
| Backlash. | 1. Splines of cardan shaft worn or | 1. Replace cardan shaft. |
| broken. | 2. Replace leaf springs in steering unit. | |
| 2. Leaf spring | ||
| Shimmy – abnormal vibration of steering (tire pattern can cause vibration) |
1. Air accumulation in steering | 1. Bleed the cylinders and find the source |
| system. | of the air accumulation and have it | |
| 2. Worn mechanical connections and | removed. | |
| wheel bearings. | 2. Replace worn parts. | |
| 3. Leaky dual shock valves and | 3. Repair or replace dual shock valves, | |
| suction valves or broken springs. | suction valves or the springs. | |
| The steering wheel can be turned continuously without turning the wheels. |
1. No oil in the tank. | 1. Fill system with clean oil and bleed the |
| 2. Steering cylinder piston seals | system. | |
| leaking badly | 2. Repair or replace cylinder(s) | |
| . | . | |
| 3. Shock valve failure. | 3. Remove shock valves and repair or | |
| replace, then reset pressure level. | ||
| The operator cannot feel resistance when the steered wheels turn to the stops. |
1. Shock valves are set to | 1. Adjust shock valve settings to at least |
| approximately the same setting as | 500 psi (34 bar) higher than steering | |
| steering PRV. | PRV setting | |
| 2. Dirt particles causing | . | |
| 2. Clean system and fill with clean oil. | ||
| Heavy impacts in steering wheel in both directions. |
1. Incorrect setting of cardan shaft | 1. Adjust setting (timing) |
| and gear wheel setting (timing) | . | |
| . | ||
| Kickback from system. | 1. Dirt particles delaying spool | 1. Remove and overhaul flow amplifier. |
| movement in flow amplifier. | Sample test oil to determine | |
| contamination source. Clean system, | ||
| change filter elements and fill with | ||
| fresh oil. | ||
| Slow steering | 1. Insufficient oil to the steering unit | 1. Replace the pump |
| due to defective or worn pump | . | |
| . | 2. Check or replace spring | |
| 2. Weak or damaged priority valve | . | |
| spool bias spring | ||
| The steering wheel does not pass to neutral position – tendency to “motor.” |
1. Dirt particles between spool and | 1. Clean spool and sleeve, or replace |
| spring | steering unit. Clean entire system. | |
| . | 2. Adjust pump pressure to the correct | |
| 2. Squeezing between spool and | value at steering PRV. | |
| sleeve caused by a too | 3. Replace with new springs. | |
| - | 4. Correct and adjust where necessary | |
| high system | . | |
| pressure. | ||
| 3. Leaf spring broken or without | ||
| elasticity | ||
| . | ||
| 4. Mechanical binding in steering | ||
| column. | ||
| When turning the steering wheel, the steered wheels are activated in the opposite direction. |
1. The hydraulic hoses to the steering | 1. Correctly connect the hoses. |
| cylinders have been reversed. | 2. Correct the setting | |
| 2. Incorrect mounting and setting of | . | |
| cardan shaft and gear wheel set. | ||
| Steering power too low (possibly to one side only). |
1. Pump pressure too low. | 1. Correct the pump pressure or adjust |
| 2. Malfunctioning shock valve. | the steering PRV in the flow amplifier | |
| valve. | ||
| 2. Remove and repair or replace shock | ||
| valve. | ||
| Leakage at input shaft, end cover on gear wheel set. |
1. Defective shaft seal. | 1. Replace shaft seal. |
| 2. Screws have come loose. | 2. Tighten the screws to 266 in | |
| 3. Defective discs or O | - | |
| - | lb (3 N | |
| rings. | ||
| m) | ||
| . | ||
| 3. Replace discs or O | ||
| - | ||
| rings. | ||
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