Series 520 Hydraulic Power Unit single system, super duty, diesel powered HPU.

Series 520, Hydraulic Power Unit

The Series 520 hydraulic power unit (25 - 60 GPM) is designed to meet or exceed standards set by National Stock Number Specifications. Electric motor available as prime mover. Durably engineered for the toughest applications.


Standard Features & Specifications
Super Duty Single System Hydraulic Power Unit

Hydraulic Power Unit (model #05-524-03)

The 520 super duty single system hydraulic power unit is diesel powered; electric motor available as prime mover.

  • 520 Hydraulic Power Unit Schematic

  • 520-Labeled

  • Ordering Instructions

  • Spec Sheet (PDF)

  • Performance Assured 100% Duty Cycle,
    Will Deliver Maximum Flow @ Maximum Pressure
  • Boost Pump Continuously Filters and Cools Fluid
  • Dependable PerkinsŪ Diesel Engine

  • Weather Proof Cabinet with Hose Storage
  • Heavy Duty Frame with Puncture Proof Tires
  • Complete with Spare Components for Maintenance

  • Performance Assured 100% Duty Cycle
    1. Will deliver Maximum Flow @ Maximum Pressure
    2. Reliable PerkinsŪ Diesel Engine
    3. Dependable OilgearŪ Piston Pump
  • Panel Mounted Controls for Ease of
    Operation and Safety
    1. Complete Pump Flow Adjustment (0-Full GPM)
    2. Complete Pump Pressure Adjustment
      (250-Full PSI)
    3. By-Pass Dump Valve
  • Durable All Welded Construction
    1. Heavy Duty All Welded Chassis
    2. 14 Gauge All Welded Steel Cabinet
    3. Anticorrosive and Weather Resistant Epoxy Paint
    4. Weather Proof Cabinet

  • Instrumentation
    1. High Pressure, Dual Scale Flow Meter
      (4% Accuracy)
    2. Test Quality 6" Pressure Gauge (1% Accuracy)
    3. Dual Scale Pyrometer / Oil Temperature Gauge
      (2% Accuracy)
    4. Test Quality Boost Pump Pressure Gauge
  • Safety Automatic Shut-Down
    1. Engine Low Oil Pressure
    2. Engine Over Temperature
    3. Reservoir Low Level
    4. Pressure Filter Clogged Conditions


Leading Particulars




To test independent hydraulic systems of aircraft.


a.       Boost pump for close loop circuit.

b.       Open loop configuration for filling and draining of A/C reservoir.

c.       Single system with in and outlet with a shut off valve.


a.       Maximum pressure at maximum flow: 300 - 3000 PSI, 4000 PSI

b.       Flow Range: refer to model number


PerkinsŪ Diesel Engine

Hydraulic System

a.       Axial piston pump variable stroke with proportional control of flow and pressure

b.       Fluid Sample Port

c.        Pressure filter 3 micron absolute, low pressure filter 10 micron absolute with electric clogged conditions indicator

d.       Stainless steel reservoir capacity 150% of maximum pump output (refer to model number)

e.        Pressure and return hoses 35 ft. long

f.        High volume hand pump with filter and pressure gauge for servicing aircraft's reservoir


a.       Analog pressure gauge 0-4000 PSI in pressure line and 0-200 PSI in return line (1% Accuracy)

b.       Analog read out for actual flow

c.        Flow setting by flow control valve

d.       Pressure setting by pressure relief valve

e.        Temperature shut down switch

f.        Emergency shut-down button

g.        Low pressure filter clogged conditions indicator

h.       Switch for low and high level and return pressure gauge

Control Panel

a.       Contains all control gauges and indicators for hydraulic system

b.       Accessible through hinged panel in a dust and water proof housing

c.        Illuminated to enable easy operation at night

d.       Graphic lay out for ease of operation

e.        Protective cover for control panel

Safety System

HTS have all required safeties pertaining to electrical, Hydraulic and emergency system.


a.       Strong and heavy duty chassis.                               

b.       Heavy duty frame with dip tray. Hydraulic and Electrical components completely isolated from each other.

c.        Canopy out of steel, spray painted. 

d.       Maximum towing speed 16 Km/hour, parking brake on front wheel by tow in upright position.

e.        Tie down / lifting points. Fork-lift pick-up points. 

Noise Level

a.       Less than 75 dbA at two meter distance.


a.       Bottle samplers for laboratory check of contamination to be provided with each HTS.

b.       All models incorporate in Line Sensor for connection with Hydraulic contamination.

c.        One set of hydraulic pressure and return lines, 35 ft. long

d.       One 45 Watt swiveling spot light with each HTS.

e.        One CO2fire extinguisher mounted on outside of  unit.

f.        One tool kit for routine scheduled/unscheduled maintenance with each unit.


a.       2 Sets of Operation Manual

b.       Engine maintenance and IPC manual for complete overhauling of engine


One week training, depot level maintenance on troubleshooting, rectification, and maintenance

Spare Parts

a.       Hydraulic pressure filter 6 sets and o-rings

b.       Boost pump filter 6 sets spin on elements

c.        Return filter 6 sets spin on elements

d.       Reservoir service pump filter 2 sets spin on elements

e.        Diesel engine fuel filter 4 sets

f.        Diesel engine air filter 2 sets

g.        Pump gasket kit 1 set

h.       O-ring set for all manual valves 1 set

i.         Spare puncture proof tire 1 each

j.         Availability of parts 20 years


a.       Frame and running gear 5 years

b.       Diesel engine 3 years

c.        Pumps 2 years

d.       Complete hydraulic system 2 years



Series Model 05-522-** and 05-523-**: Length 100", Width 60", Height 66"
Series Model 05-524-** and 05-525-**: Length 110", Width 75", Height 74"

PSI (bar)
HP (kW)
GPM (lpm)
Lbs. (kg)
05-522-** 450 - 4000 PSI
30 - 272 bar
60 HP
45 kw
25 GPM
95 lpm
2350 lbs
1066 kg
05-523-** 450 - 4000 PSI
30 - 272 bar
75 HP
56 kw
35 GPM
132 lpm
2813 lbs
1276 kg
05-524-** 450 - 4000 PSI
30 - 272 bar
120 HP
89 kw
50 GPM
189 lpm
3575 lbs
1621 kg
05-525-** 450 - 4000 PSI
30 - 272 bar
150 HP
112 kw
60 GPM
227 lpm
4138 lbs
1877 kg