Hi-Force HEP4 Series Instruction Manual

Operating Instruction Manual:
OM-HEP4/5-01
From Serial Number:
BN0101
1
OPERATING INSTRUCTION MANUAL
HEP4 & HEP5 SERIES | ELECTRIC DRIVEN PUMPS
•HEP4 - GENERAL DUTY, HIGH FLOW
•HEP5 - GENERAL DUTY, ULTRA-HIGH FLOW
Hi-Force HEP4 and HEP5 series Electric Driven Hydraulic Pumps are designed to operate high pressure
hydraulic cylinders and tools with a maximum working pressure of 700Bar. This manual applies to the Hi-
Force HEP4 and HEP5 series, Electric Driven Hydraulic Pumps. It contains the latest product information
available at the time of publication and approval. Hi-Force reserves the right to make changes to this
document at any time without notice.
This ‘original instructions’ document assumes that the operator carrying out any operation with this
product is trained and competent to do so. This manual does not attempt to cover all details or variations
in the equipment. Nor does thismanual claim to provide for every possible contingency met in connection
with the installation, operation, or maintenance thereof. Should further information be desired, or should
a particular problem arise which is not covered in sufficient detail, the matter should be referred to
Hi-Force.

Operating Instruction Manual:
OM-HEP4/5-01
From Serial Number:
BN0101
2
Table of Contents
1.0 Inspection upon Receipt......................................................................................... 3
2.0 Safety Precautions.................................................................................................. 3
2.1 Introduction ........................................................................................................3
2.2 Work Area Safety................................................................................................3
2.3 General Hydraulic System Safety Precautions.................................................3
2.4 Hydraulic Pump Specific Safety Precautions...................................................5
3.0 Declaration of Incorporation / Conformity............................................................ 5
4.0 Component Identification....................................................................................... 6
5.0 Installation/Setup .................................................................................................... 8
5.1 Before First Use..................................................................................................8
5.2 Filling the Pump with Oil....................................................................................9
5.3 Electrical Connection.........................................................................................9
5.4 Hydraulic Connections..................................................................................... 10
5.5 Bleeding Trapped Air from the System...........................................................10
6.0 Operation............................................................................................................... 11
6.1 Setting the Pressure Relief Valve.................................................................... 11
6.2 Pumps with Manual Valves..............................................................................12
6.3 Pumps with Solenoid Valves...........................................................................13
7.0 Maintenance and Storage..................................................................................... 13
8.0 Specifications........................................................................................................ 14
8.1 HEP4 Specifications.........................................................................................14
8.2 HEP4 Electrical pump Characteristics............................................................ 15
8.3 HEP5 Specifications.........................................................................................15
8.4 HEP5 Electrical pump Characteristics............................................................ 15
10.0 System Components / Accessories................................................................... 16
11.0 Troubleshooting.................................................................................................. 17
NOTE: Images contained within this document are for illustrative purposes ONLY.

Operating Instruction Manual:
OM-HEP4/5-01
From Serial Number:
BN0101
3
1.0 Inspection upon Receipt
Upon receipt of the product, visually inspect the item for any evidence of shipping damage. Please note: the
warranty does not cover shipping damage. Notify the courier immediately if shipping damage is found and
refrain from putting the product into service. The carrier is responsible for repair and replacement costs
resulting from damage that occurred in transit.
2.0 Safety Precautions
2.1 Introduction
Read and follow all the instructions and safety warnings carefully before handling, installation or
use of any hydraulic equipment. Failure to do so could lead to equipment damage, equipment
failure, personal injury or even death. Hi-Force will not be held responsible for any damage to the
equipment, injury or death resulting from the unsafe use of, lack of maintenance to, or incorrect operation of
the product. If in doubt on the correct use of any Hi-Force equipment, contact your nearest Hi-Force office
or distributor. Only qualified personnel should be allowed to operate hydraulic equipment. If an operator has
not been trained on high-pressure hydraulic equipment and its safe usage, consult your local Hi-Force sales
office or distributor who can offer training courses for operators.
2.2 Work Area Safety
•Keep work areas clean and well lit. Cluttered spaces and inadequate lighting can result in
unnecessary accidents.
•Keep unauthorised persons at a safe distance from the task site.
•NEVER use the tools in the presence of inflammable liquids, gases or material.
•DO NOT use the tools in potentially explosive atmospheres (ATEX) this tool is NOT ATEX approved.
2.3 General Hydraulic System Safety Precautions
Failure to observe and obey the following safety precautions could result
in property damage, significant personal injury or death;
•When operating any hydraulic equipment, all operators should ensure that all necessary personal
protective equipment (PPE) is worn, as specified by their employer. Steel toe-cap safety shoes,
safety glasses/visor, and protective gloves should be worn at all times. All relevant risk assessments
should be completed before the use of the equipment.
•Keep hydraulic equipment away from open flames and direct heat.
•NEVER handle a pressurised hydraulic hose. Hydraulic oil escaping under pressure from a ruptured
hose can penetrate the skin and lead to a significant medical emergency, and in some cases, death.
Should this incident occur, seek out medical attention immediately.

Operating Instruction Manual:
OM-HEP4/5-01
From Serial Number:
BN0101
4
•The system operating pressure MUST NOT exceed the pressure rating of the lowest-rated
component in the system. It is good practice to use a pressure gauge to monitor the entire system.
•Only use hydraulic tools/cylinders in a complete and tested, coupled system. NEVER attempt to use
a tool/cylinder that is not correctly coupled to its operational pump. NEVER pressurise an uncoupled
coupler/s.
•NEVER attempt to disconnect a hose from a hydraulic system until the systems pressure has been
completely released. Doing so can result in that pressure becoming trapped within the system and
relieving trapped pressure can be dangerous.
•NEVER try to relieve trapped hydraulic pressure in the system by loosening or attempting to remove
the coupler. Trapped hydraulic pressurecan cause a loosened coupler to dislodge unexpectedly with
great force. This action could result in serious personal injury or death, as the coupler could become
a projectile and hit operatives in the working area.
•Loosening a coupler under pressure can result in the escape of hydraulic oil at high pressure, which
can penetrate the skin and cause significant injury or death.
•NEVER use a hammer and punch to unseat a coupler check valve that is under pressure. Doing so
could result in the sudden, uncontrolled release of hydraulic oil at high pressure, which could cause
significant injury or death.
•Immediately replace any worn or damaged parts using genuine Hi-Force parts only.
•DO NOT remove any labels from the product. Replace any damaged or unreadable label
immediately.
Failure to observe and obey the following safety precautions could result
in property damage, equipment damage or minor/moderate personal injury;
•NEVER lift or carry any hydraulic components by the hose or hoses connected to them.
•Avoid damaging hydraulic hose. ALWAYS route hoses to ensure thatthey are free from sharp bends
and kinks. Using a bent or kinked hose will result in severe back-pressure, which can lead to hose
failure.
•ALWAYS operate the system under no-load conditions before the actual operation, to ensure there
is no air trapped in the hydraulic circuit.
•Servicing of hydraulic equipment must only be undertaken by a qualified technician.
•DO NOT drop or place heavy objects on a hydraulic hose, as this may cause
internal damage, which could result in rupture of the pressurised hose. A
ruptured hose could cause significant damage to components and possible
severe injury to personal operating nearby.

Operating Instruction Manual:
OM-HEP4/5-01
From Serial Number:
BN0101
5
2.4 Hydraulic Pump Specific Safety Precautions
Failure to observe and obey the following safety precautions could result
in property damage, serious personal injury or death;
•NEVER invert the pump or lay it on its side, either in use, in transport or in storage.
•DO NOT weld any items to the pump or modify it in any way from its delivered condition. Your
warranty may be invalidated, and it could lead to serious personal injury.
•NEVER exceed the maximum rated capacity of any hydraulic cylinder/tool. Hi-Force manufactures
its hydraulic pumps to operate at a maximum working pressure of 700 BAR (10,000 PSI). DO NOT
connect a cylinder/tool with a lower pressure capacity rating to any Hi-Force pump of this model
series.
•This pump is not suitable for work which takes place in explosive environments.
Failure to observe and obey the following safety precautions could result
in property damage, equipment damage or minor/moderate personal injury;
•ALWAYS stand the pump on a stable level surface during operation.
•BEWARE of hot surfaces on the motor. Do not obstruct the flow of cooling air around the motor.
•To protect your warranty, only use the hydraulic oil grade as specified in Section 5.2.
3.0 Declaration of Incorporation / Conformity
Hi-Force declares that this product has been tested and complies with the standards set out in the relevant
EU directives. The EU Declaration of Incorporation / Conformity is included as Annex A to this instruction
document and is supplied with all shipments of this product.

Operating Instruction Manual:
OM-HEP4/5-01
From Serial Number:
BN0101
6
4.0 Component Identification
1
Hydraulic Oil Drain Plug
8
Oil Filler Breather Cap
2
Hydraulic Oil Level Gauge
9
Motor ***
3
Hydraulic Service Connections *
10
On/Off Switches
4
Directional Control Valve **
-
5
Adjustable Pressure Relief Valve
-
6
Oil Reservoir
-
7
Modular Electric Tray
-
* One or two ports, depending on valve type.
** If fitted (Type will vary)
*** Motors will vary depending on supply requirements
Figure 4.1: Component Identification

Operating Instruction Manual:
OM-HEP4/5-01
From Serial Number:
BN0101
7
Figure 4.2: Component Identification

Operating Instruction Manual:
OM-HEP4/5-01
From Serial Number:
BN0101
8
5.0 Installation/Setup
5.1 Before First Use
1. Immediately after unpacking, examine the pump for signs of transit damage and if found contact the
shipping company.
2. Remove the temporary transit fitting / plate which is fitted in the position of the oil filler breather cap
(8) and fit the oil filler breather cap which is packed separately.
3. Establish the oil level in the oil reservoir using the level gauges (2). Depending on the shipping
method used, the reservoir may either be supplied full or empty. If the reservoir is empty it must be
correctly filled before use (See section 5.2). If the pump was supplied full of oil, no further action is
required.
IMPORTANT: Running the pump without oil will result in damage.
CAUTION: Ensure the oil level does not fall below the minimum level as shown by the lower
indicator (2).
4. Remove the steel or plastic hexagon headed plugs and make hydraulic connections to the service
ports (3). These ports have a 3/8” NPT female thread and the corresponding male connections
should be wrapped with PTFE tape or other suitable sealant.
NOTE: On a pump equipped with a 3-way valve the service port is the one on the right-hand side,
when viewed from the front. (See figure 4.1).
5. Ensure the lever of the hydraulic directional control valve (4) is set to the neutral position: This is fully
anti-clockwise for models with a 2-way valve, or the central position for models with a 3-way or
4-way valve.
NOTE: Where valves are remotely mounted, make sure they are adjusted such that pressure will not
build up during the starting operation. See section 8 for applicable models.
6. Make sure that the voltage indicated on the motor rating plate corresponds with the available supply.
7. Connect the motor to required power source. (See section 5.3)
8. Check the direction of rotation of the motor by pressing the green ‘ON’ button (10), then immediately
pressing the red ‘OFF’ button. While doing this observe the motor fan. The motor should run in a
clockwise direction when viewed from above. If the motor turns anti-clockwise, check the wiring of
the electrical connector.
CAUTION: Running the pump with the motor turning in the incorrect direction may damage the low-
pressure pump unit.

Operating Instruction Manual:
OM-HEP4/5-01
From Serial Number:
BN0101
9
9. The pump is fitted with an adjustable pressure relief valve (5) to restrict the output pressure to any
desired value, up to the maximum working pressure of the pump. For further details refer to 6.1
Check the adjustable pressure relief valve is working:
NOTE: Checking / setting the relief valve pressure is to be done with the hydraulic female couplers
fitted to the service ports only.
•Press the green ‘ON’ button (10) and turn the directional control valve to the advance position (for 2
way valves turn the lever fully clockwise, for the 3 and 4-way valves turn the lever fully anti-clockwise
and for the solenoid valves press and hold the ‘advance’ button on the pendant).
•Then release the locking feature and turn the control knob clockwise to increase the relief valve
setting (the pressure reading on the gauge should increase) and anti-clockwise to decrease the relief
valve setting (the pressure reading on the gauge should decrease).
5.2 Filling the Pump with Oil
IMPORTANT: The HEP4 & HEP5 series of hydraulic pumps use ISO46 Grade Hydraulic Oil.
•Stand the pump on a firm, level surface.
•Remove the filler cap (8) from the filler breather.
•Fill the reservoir with clean, high quality ISO46 hydraulic oil via the filler breather until the oil level
reaches the upper level indicator (2).
•Replace the filler cap (8) on the filler breather.
NOTE: More hydraulic oil can be added to the reservoir to assist with cooling if required, but NEVER more
than 25mm below the tank lid.
IMPORTANT: Only add oil to the reservoir when the connected cylinder/tool is fully retracted. Failure to do
so will result in the system containing more oil than the reservoir can hold.
5.3 Electrical Connection
Before making an electrical connection, refer to the data plate located on the motor (9) for voltage and
current requirements. Once satisfied the supply is suitable, an electrical connection can be made.
NOTE: Supply voltages vary from country to country. Hi-Force pumps will operate within the normal voltage
tolerance ranges, but in extreme cases where they are operated for long periods at high pressures
and in low voltage conditions, the motor may overheat and shut down.
NOTE: A common cause of pump failure is the use of long extension cables to connect the pump to the
mains supply. The pump should be situated as close as possible to the wall outlet.

Operating Instruction Manual:
OM-HEP4/5-01
From Serial Number:
BN0101
10
5.4 Hydraulic Connections
Connect the hydraulic hose/s between the cylinder/tool and the pump, ensuring that the coupling/s (if fitted)
are fully hand-tightened only. NEVER use wrenches in an attempt to connect the coupling/s. Incorrectly
connected coupling/s are one of the most common causes of faulty operation.
IMPORTANT: Make sure that all coupler threads are fully engaged.
5.5 Bleeding Trapped Air from the System
The bleeding of trapped air from a hydraulic system must only be performed by
qualified personnel who have been trained and are competent to do so.
Cylinders, tools and hoses are not always completely filled with oil when new. For safe and efficient
operation, trapped air must be removed from the system. The follow procedure must be carried out with the
cylinder/tool connected to the pump, but not operating under load.
To remove air from the system, proceed as detailed below:
•Make sure the oil filler breather cap (8) is fitted.
•With all hydraulic connections made, position the cylinder/tool below the level of
the hydraulic pump, as illustrated in figure 5.1.
Single-Acting: With smaller single-acting cylinders, positioned them with the
piston facing downward, as illustrated in figure 5.1
Double-Acting: If possible, position double-acting cylinders on their side with the
couplers facing upward, as illustrated in figure 5.2
•Using the pump, fully advance and retract the cylinder/tool piston several times
until the operation is smooth. (See section 6 for details of pump operation).
NOTE: When longer hoses are used (especially in the case of smaller capacity
cylinders), the above procedure may not remove all the air from the system. In these
cases, contact your Hi-Force representative for advice on pre-filling hoses with
hydraulic oil.
Figure 5.1
Figure 5.2

Operating Instruction Manual:
OM-HEP4/5-01
From Serial Number:
BN0101
11
6.0 Operation
Hi-Force will not always be aware of what equipment this pump will be used to power. It is the responsibility
of the owner and all operators to read, understand and comply with all appropriate safety warnings and
operating instructions relating to the equipment being used.
6.1 Setting the Pressure Relief Valve
NOTE: Setting the relief valve pressure is to be done with hydraulic female couplers fitted to the service
ports only. I.e. No hoses or cylinders/tools fitted.
The procedure for setting the relief valve pressure is as follows:
•Turn the pump on by pressing the green ‘ON’ button (10)
•Place the pump in advance mode.
For 2-Way manual valves, turn the level fully clockwise (See figure 6.1).
For 3 & 4-Way manual valves, turn the lever fully anti-clockwise (See figure 6.2).
For solenoid valves, press and hold the ‘advance’ button on the pendant.
Increasing the Pressure Setting
•Release the locking feature and turn the control knob slowly (5) clockwise until the required pressure
is read on the pressure gauge.
•Engage the locking feature to lock the relief valve at the desired pressure.
Decreasing the Pressure Setting
•Release the locking feature and turn the control knob (5) anti-clockwise until a pressure value lower
than the required pressure is read on the gauge.
•Turn the control knob slowly clockwise until the required pressure is read on the gauge.
•Engage the locking feature to lock the relief valve at the required pressure.
NOTE: ALWAYS adjust up to the desired pressure and NEVER down. When setting the pump to a lower
pressure, reduce the pressure below the desired value (anti-clockwise) and then increase back up
to the desired pressure (clockwise) as read on the gauge.
NOTE: It’s good practice to zero the pressure before storing away. Turn the control knob anti-clockwise until
the pressure gauge reads zero.

Operating Instruction Manual:
OM-HEP4/5-01
From Serial Number:
BN0101
12
6.2 Pumps with Manual Valves
1. Set the adjustable pressure relief valve (5) if required. See section 6.1 for details.
2. With all hydraulic connections and an electrical connection made turn the motor on by pressing the
green ‘ON’ button (10).
3. Operate the directional control valve (4) to control the cylinder/s or tool/s in use.
For pumps with a 2-way valve: Turning the lever fully clockwise will supply oil to the service port and
advance the cylinder/tool. Turning the lever anti-clockwise will retract the cylinder/tool. (See figure
6.1)
For pumps with a 3-way or 4-way valve: Mid position is the load hold position. Turning the lever so
that it is above the service port (anti-clockwise) will supply oil to the service port and advance the
cylinder/tool. Moving the lever away from the service port (clockwise) will connect the service port to
the tank and retract the cylinder/tool. (See figure 6.2)
Figure 6.1: 2-Way Manual Valve
Figure 6.2: 3 & 4-Way Manual Valves
NOTE: 2nd Port only on 4-Way Valves

Operating Instruction Manual:
OM-HEP4/5-01
From Serial Number:
BN0101
13
6.3 Pumps with Solenoid Valves
1. Set the adjustable pressure relief valve (5) if required. See section 6.1 for details.
2. With all hydraulic connections and electrical connection made and turn the motor on by pressing the
green ‘ON’ button (10).
3. Press and hold the ‘advance’ button on the pendant to advance the cylinder/tool. Release the button
once the cylinder/tool has been advanced the desired amount. The cylinder/tool will remain in the
load holding position when the button is released.
4. Press and hold the ‘retract’ button to retract the cylinder/tool. Release the button once the
cylinder/tool has been retracted.
IMPORTANT: ALWAYS fully retract the cylinder/tool at the end a job/operation, before any disconnections
are made.
7.0 Maintenance and Storage
•Inspect the pump for damage after each use.
•Change the oil every 500 working hours using high quality ISO46 hydraulic oil.
•Zero the pump pressure before storing.
•Have the pump serviced regularly by a Hi-Force authorised repair centre.

Operating Instruction Manual:
OM-HEP4/5-01
From Serial Number:
BN0101
14
8.0 Specifications
An average A-Weighted sound pressure level of 75dB was measured for undefined workspaces, as per EU
Directive 2006/42/EC Section 1.7.4.2 (u).
8.1 HEP4 Specifications
Refer to the nameplate on the pump for model identification.
HEP4 │ELECTRIC DRIVEN PUMPS –GENERAL DUTY, HIGH FLOW
Model
Number
Valve
Type
Oil
Capacity
Maximum Flow Rate
(litres/minute)
Motor
Voltage
Weight
(litres)
1st Stage
2nd Stage
(kg)
HEP410141
P-T Plate
40
9
1
110V 50Hz - 1Ph
88.5
HEP410142
P-T Plate
40
9
1
230V 50Hz - 1Ph
88.5
HEP410144
P-T Plate
40
9
1
400V 50Hz/460V
60Hz - 3Ph
88.5
HEP410161
P-T Plate
60
9
1
110V 50Hz - 1Ph
120
HEP410162
P-T Plate
60
9
1
230V 50Hz - 1Ph
120
HEP410164
P-T Plate
60
9
1
400V 50Hz/460V
60Hz - 3Ph
120
HEP410241
2-way
40
9
1
110V 50Hz -1Ph
89
HEP410242
2-way
40
9
1
230V 50Hz - 1Ph
89
HEP410244
2-way
40
9
1
400V 50Hz/460V
60Hz - 3Ph
89
HEP410261
2-way
60
9
1
110V 50Hz - 1Ph
120.5
HEP410262
2-way
60
9
1
230V 50Hz - 1Ph
120.5
HEP410264
2-way
60
9
1
400V 50Hz/460V
60Hz - 3Ph
120.5
HEP410341
3-way
40
9
1
110V 50Hz - 1Ph
89
HEP410342
3-way
40
9
1
230V 50Hz - 1Ph
89
HEP410344
3-way
40
9
1
400V 50Hz/460V
60Hz - 3Ph
89
HEP410361
3-way
60
9
1
110V 50Hz - 1Ph
120.5
HEP410362
3-way
60
9
1
230V 50Hz - 1Ph
120.5
HEP410364
3-way
60
9
1
400V 50Hz/460V
60Hz - 3Ph
120.5
HEP410441
4-way
40
9
1
110V 50Hz - 1Ph
89
HEP410442
4-way
40
9
1
230V 50Hz - 1Ph
89
HEP410444
4-way
40
9
1
400V 50Hz/460V
60Hz - 3Ph
89
HEP410461
4-way
60
9
1
110V 50Hz - 1Ph
120.5
HEP410462
4-way
60
9
1
230V 50Hz - 1Ph
120.5
HEP410464
4-way
60
9
1
400V 50Hz/460V
60Hz - 3Ph
120.5

Operating Instruction Manual:
OM-HEP4/5-01
From Serial Number:
BN0101
15
8.2 HEP4 Electrical pump Characteristics
Refer to the nameplate on the pump for model identification.
8.3 HEP5 Specifications
Refer to the nameplate on the pump for model identification.
HEP5 │ELECTRIC DRIVEN PUMPS –GENERAL DUTY, ULTRA-HIGH FLOW
Model
Number
Valve
Type
Oil
Capacity
Maximum Flow Rate
(litres/minute)
Motor
Voltage
Weight
(litres)
1st Stage
2nd Stage
(kg)
HEP517144
P-T Plate
40
17.5
1.9
400V 50Hz/460V
60Hz - 3Ph
88.5
HEP517164
P-T Plate
60
17.5
1.9
400V 50Hz/460V
60Hz - 3Ph
120
HEP517244
2-way
40
17.5
1.9
400V 50Hz/460V
60Hz - 3Ph
89
HEP517264
2-way
60
17.5
1.9
400V 50Hz/460V
60Hz - 3Ph
120.5
HEP517344
3-way
40
17.5
1.9
400V 50Hz/460V
60Hz - 3Ph
89
HEP517364
3-way
60
17.5
1.9
400V 50Hz/460V
60Hz - 3Ph
120.5
HEP517444
4-way
40
17.5
1.9
400V 50Hz/460V
60Hz - 3Ph
89
HEP517464
4-way
60
17.5
1.9
400V 50Hz/460V
60Hz - 3Ph
120.5
8.4 HEP5 Electrical pump Characteristics
Refer to the nameplate on the pump for model identification.
Motor
Voltage
Motor
Frequency
Motor
Current
Motor
Output
110V-1Ph
50 Hz
16 A
1.1 kW
230V-1Ph
50 Hz
9.3 –9.5 A
1.5 kW
400V-1Ph
50 Hz
3.6 A
1.5 kW
460V-1Ph
60 Hz
3.2 A
1.5 kW
Motor
Voltage
Motor
Frequency
Motor
Current
Motor
Output
400V - 3Ph
50 Hz
6.3 A
3.0 kW
460V - 3Ph
60 Hz
5.3 A
3.0 kW

Operating Instruction Manual:
OM-HEP4/5-01
From Serial Number:
BN0101
16
10.0 System Components / Accessories
(Refer to the Hi-force website or latest Hi-Force catalogue, Section: System Components for further
details)
•High Pressure Hydraulic Hoses
•Manifolds and Manifold Assemblies
•Flow Control Valve
•Pressure Gauges and Gauge Mounting Blocks
•High-Pressure Couplings and Fittings
•Wheel Trolley

Operating Instruction Manual:
OM-HEP4/5-01
From Serial Number:
BN0101
17
11.0 Troubleshooting
Hi-Force HEP4 & HEP5 electric driven hydraulic pumps should be serviced and repaired only by
authorised Hi-Force repair centres. The following table gives possible causes and solutions for common
problems.
TROUBLESHOOTING GUIDE
Problem
Possible Cause
Solution
1. Pump will not start.
a. Power not connected.
Connect power.
b. Damaged power cord.
Repair or replace power cord.
c. Circuit breaker tripped.
i. Reset Circuit breaker.
ii. Ensure breaker is adequately rated.
d. Damaged pendant.
Contact your local Hi-Force office/distributor.
e. Blown fuse.
Replace blown fuse.
f. Burnt out motor.
Contact your local Hi-Force office/distributor.
2. Motor stalls before full
operating pressure is
reached.
a. Low supply voltage.
i. Use heavier gauge extension cord.
ii. Turn off excess electrical loads.
3. Pump runs but will not
build up to full operating
pressure.
a. Reservoir breather has not been
installed.
Remove transit plate and install reservoir
breather as per section 5.1
b. Low oil level.
Add oil as per section 5.2.
c. Adjustable relief valve incorrectly
set.
Adjust relief valve pressure as per
section 6.1.
d. External oil leak in system.
Contact your local Hi-Force office/distributor.
4. Noisy Operation
a. Air trapped in the system.
Bleed air from the system as per section 5.5
b. Low oil level
Add oil as per section 5.2
c. Reservoir breather has not been
installed.
Remove transit plate and install reservoir
breather as per section 5.1
5. Pump builds to full
pressure, but
cylinder/tool does not
advance/operate.
a. Advance or return flow line to
cylinder/tool restricted or blocked.
Check couplers (if fitted) for full engagement.
6. Pump running hot.
a. Low oil level.
Add oil as per section 5.2.
b. Advance or retract flow restricted.
Check couplers (if fitted) for full engagement.
c. High pressure leakage at pump.
Contact your local Hi-Force office/distributor.

Operating Instruction Manual:
OM-HEP4/5-01
From Serial Number:
BN0101
18
TROUBLESHOOTING GUIDE (continued…)
Problem
Possible Cause
Solution
7. Cylinder/tool not
functioning correctly.
a. Cylinder/tool incorrectly connected
to pump.
Check for correct system setup. Check
couplers (if fitted) for full engagement
b. Pump solenoid faulty.
Contact your local Hi-Force office/distributor.
c. Cylinder/tool fault.
See cylinder/tool’s troubleshooting guide or
contact your local Hi-Force office/distributor.
d. Low oil level
Add oil as per section 5.2.
e. Air trapped in the system
Bleed air from the system as per section 5.5
8. Cylinder/tool will not
retract.
a. Valve malfunction.
Contact your local Hi-Force office/distributor.
b. Return flow line restricted or
blocked.
i. Check couplers (if fitted) for full
engagement.
ii. Run motor while retracting cylinder/tool.
9. Pressure gauge does
not read zero when
pump motor is
stopped.
a. Pressure not relieved from system.
Turn the adjustable pressure relief valve (5)
fully anti-clockwise to release the pressure.
10. Gauge displays no
pressure reading.
a. faulty gauge.
Contact your local Hi-Force office/distributor
b. pump will not build pressure.
See problem 3 above.

Operating Instruction Manual:
OM-HEP4/5-01
From Serial Number:
BN0101
19
Head Office:
Hi-Force Limited
Prospect Way, Daventry
Northamptonshire NN11 8PL
United Kingdom
Tel: + 44 1327 301000 | Fax: + 44 1327 706555
www.hi-force.com
Regional Offices:
For information on our offices worldwide, scan the below QR code