The universal hydraulic servicing trolley is designed to provide pressurized hydraulic oil from its reservoir to the systems of different aircraft types for testing purposes. It can simultaneously supply two independent aircraft hydraulic systems. It is used on aircraft like the Sukhoi Su-30MKI, MiG-29, MiG-21, Mirage 2000 and Hal Tejas. The trolley documentation provides specifications, operating procedures and safety guidelines for its use.

3.  The UNIVERSAL HYDRAULIC SERVICING is specially designed and
developed for the GROUND SERVICING of two independent aircraft
systems. It is used for actuation of the aircraft hydraulic system through
the supplied pressurized hydraulic oil from the trolley to the aircraft,
comprising of a pressurized reservoir, with filtered and de-aerated fluid at
flow and pressure characteristics required for testing. The
Trolley (HST300U) is suitable for wide range of fighter aircraft, military
transport aircraft, and helicopters used in Indian Air Force
 It is mainly used for Sukhoi Su-30MKI, MIG -29, MIG- 21, Mirage-2000,
Hal- Tejas.

4.  Continuous filtered high pressure hydraulic oil supply to two independent
aircraft systems.
 Delivery Pressure & flow can be sleeplessly controlled from the panel. Also
ready selection to suit the type of aircraft can be done through microprocessor
based selector switch.
 A System regulating the hydraulic fluid level in each system of aircraft and
also enables to decrease or increase the level of aircraft reservoir at quantitative
volume of oil.
 Instrumentation of different parameters like delivery pressure boost
pressure, return pressure, delivery flow, temperature etc.
 Trolley tank can be completely isolated and aircraft tank can be used in the
circuit and including both tanks in the circuit is also possible.
 Consequently can be bled from the trolley circuit through vacuum system
working at 400 mbar to 200 mbar( abs)
 Hand pump is provided for external pressure tests.

6. GENERAL SPECIFICATION OF TROLLEY AND HYDRAULIC SYSTEM
 A. Specifications of trolley structure
 1. Overall dimensions of unit (nominal) : L3400xW1500xH1750 mm
 2. Track / Wheel base : 1320 mm / 2040 mm
 3. Number of Wheels : 2 nos. (Rear); 2 nos. (Front)
 4. Brake : Parking brakes for Rear wheels & over run brake.
 5. Suspension : Leaf springs for front & rear axles
 6. Tow bar : Folding type
 9. Towing speed : 15 Km/h (max.)
 11. Steering mechanism : Automobiles steering

7. OPERATING PROCEDURE
 Switch ON the Engine Electricals.
 Engage the Selector valve position in both the system from Trolley tank to the
Aircraft tank.
 Actuate the Solenoid operated Air assisted valve no and through the DC valve
(83.2) actuation.
 In Unload Position, Open fully the Pressure relief valve No and in both system.
 Connect the pressure hose and return hose to aircraft hydraulic system.
 Start the Engine.
 Regulate the Relief valve and manually to set the upstream pressure as per the
Aircraft Requirement.
 Monitoring upstream pressure System–I gauge
 And System-II gauge

 Regulate the Flow control knob manually to control the flow rate and monitor the
same on the Flow rate display unit in LPM(38.1) & (38.2).

9. OPERATING PROCEDURE
 Switch ON the Engine Electricals.
 Buffer chamber (71.0) is having Compressed Air trapped @7 bar set
through the relief valve 7Bar.
 De-actuate the 5/2 DC valve (75.1) & 3/2 DC valve (75.2) in normal
position it is connected through the selector switch for COMPRESSED
AIR in System-II.
 Start the Engine.
 As soon as the Air Pressure Gauge (73.0) monitor the set pressure.
 Shut down the Engine.
 Actuate the 5/2DC valve (75.1) allowing closing circuit for trapping
compressed air.

10. OPERATING PROCEDURE
 Switch ON the Engine Electricals.
 Engage the selector switch to VACUUM SYSTEM on System-I.
 Start the Engine.
 Monitor the float of the Rota meter Pressure Gauge (73.0)
monitor the set pressure. Reaches the Green REGION it indicate
that deration completes.
 Monitor the Vacuum gauge (85.0) to read the set pressure of
200mBar (abs).
 Shut down the Engine.

11. Do’s:
 Observed the complete hydraulic and pneumatic circuit and after getting
rough Idea, read the manual carefully.
 The hydraulic and Pneumatic system must be clean at all times. Many
failures to hydraulic Equipment are caused by dust or foreign matter
introduced in to the system through lack of care during operation or
maintenance. Check the cleanliness of the fluid and compressed air.
 Ensure proper ventilation, which is essential for cool, clean air in-take.
 Ensure the tyre air pressure is at specified values.
 Always keep the parking brakes applied when the unit is running.
 Ensure that all nuts, bolts, screws, belts, clamps, pipe connections and
covers are properly tightened.
 Ensure that all filter elements are clean..

12.  The hydraulic fluid in the trolley should not be mixed with any other
fluid. Ensure that the hydraulic system of the aircraft to be tested is of
the same approved specification that of the trolley.
 Ensure the battery connections and condition. Top-up with electrolyte if
required.
 Ensure that pressure control valves of both systems are kept at
minimum level before starting.
 Adjust the cylinder Stroke under working condition.
 LOAD switches of system-1 & system-2 are kept in UNLOAD position
before starting.
 In all cases system to be first runs with trolley tank selection, before
selector valves shifted to aircraft tank position.
 Selector valves shall be operated only when the engine is OFF.

13. DON’T:
 Do not Run the system if suction valve is closed.
 Do not disturb any Items of System while system is running.
 Do not keep the door open when the unit is in running condition.
 Do not use cotton waste for cleaning purpose (Use lint free cleaning cloth)
 Do not operate the unit when any part of the engine / system is removed.
 In case of any fault; do not attempt starting unit unless fault is rectified.
 Do not turn off the fuel supply for stopping the engine.
 Do not allow the engine to run for long periods on NO-LOAD.
 Do not bring a naked light near the battery, when it is on charge.
 Do not tow the trolley while the unit is running.
 Do not tow the trolley more than 15 km/h speed.
 Do not leave the selector valve lever in intermediate position.
 Do not attempt to run, when oil temperature is more than 70 °C.
 Do not run the system if filter clogging indication comes on user panel screen

14. THANK YOU