INSTRUCTION MANUAL – AIR DRIVEN HYDRAULIC PUMPS:
Model Series: AHP1120, AHP1120R, AHP1121, AHP1121R, AHP1122, AHP1122R, AHP1141, AHP1142,
HAP21011, HAP21012, HAP21014, HAP21016, HAP21021, HAP21022, HAP21024, HAP21026, HAP21031,
HAP21032, HAP21034, HAP21036, HAP21041, HAP21042, HAP21044, HAP21046,
Hi-Force Limited – Prospect Way – Daventry – Northants NN11 8PL – United Kingdom
Tel: +44(0) 1327 301000: Fax: +44(0) 1327 706555: Website: www.hi-force.com
7.2 - Cleaning the air filter
There is an air filter inside the air inlet
connection (Fig 12).
Use a slotted tip screwdriver of the
appropriate size to unscrew the filter
from the air inlet connection until it is
extracted.
Clean the filter with compressed air
and then refit and screw it into position.
Do not over-tighten the filter or
damage may ensue.
Reconnect the air-line quick coupler
after binding the thread with Teflon
tape.
If
the
air
filter
is
excessively
contaminated or damaged, it must be
renewed.
Order
a
new
filter
from
the
manufacturer, referring to the list of
spare parts at the end of this manual.
7.3.1 - Checking the hydraulic oil on the 2,5
Litre pump (AHP1120/AHP1120R)
Periodically check that the pump contains the
correct quantity of hydraulic oil by checking
the level on the sight glass (Fig 13). If the oil
level, with cylinder retracted, is below minimum
(E, Fig 13a), refill using the recommended types
of oil.
7.3.2 - Checking the hydraulic oil on the 5/10
Litre pump (AHP1121(R)/ 1122(R)/ 1141/ 1142)
Periodically check the oil level, which must be
between the two notches on the oil cap
dipstick (F in Fig 13b).
7.4 - Hydraulic oil change
Change the oil at intervals of 250 duty hours.
This operation must be performed when the
cylinder is fully retracted: USE ONLY HI-FORCE
HFO46 OIL for your AHP Pump.
If the pump is mounted vertically,
disassemble
it
and
position
it
horizontally.
Use a slotted tip screwdriver to remove
the filler plug (Fig 1).
Empty the pump of oil by turning it
upside down over a suitable container.
Allow all the oil to flow into the
container and then fill the pump with
the quantity and type of new oil
specified above.
Clean the filler opening with a clean
cloth and refit the plug, pressing it fully
down or, if necessary, to the partially
inserted breather position.
7.5 - Troubleshooting
The chart below describes the possible issues
that could occur during operation of the
pump, together with an indication of the
appropriate corrective action. If the prescribed
action fails to solve the problem, contact the
manufacturer.
PROBLEM
POSSIBLE CAUSE
CORRECTIVE ACTION
Pump cannot be
started
Compressed air line closed or
clogged
Check compressed air supply to
pump
Insufficient air pressure
Check compressed air supply to
pump is between 2.8 and 10Bar
Air filter dirty or clogged
Clean or Renew
Oil leak in the main hydraulic
circuit.
Check the circuit for leaks and
repair as necessary.
Pump internal leak
Check for leaks and return
pump to manufacturer for
repair
Low oil level
Check level and top up as
necessary
Insufficient air pressure
Check compressed air supply to
pump is between 2.8 and 10Bar
Internal relief valve incorrectly
set.
Contact the manufacturer
Oil leak in the main hydraulic
circuit
Check for oil leaks and ask the
manufacturer
Excess load
Reduce
Oil circulation fault
Check if pipelines are
obstructed or if cylinder is
working correctly
Oil leak in the main hydraulic
circuit
Check the circuit for leaks and
repair as necessary.
Pump internal fault
Check for leaks and ask the
manufacturer
Oil pressure line obstructed or
coupling incorrectly connected
Check oil pressure line.
If piston is designed to return
under gravity, ensure load is
sufficient
Increase load on cylinder
Cylinder spring broken
Repair
Cylinder release valve not
working
Repair cylinder
Oil pressure line obstructed or
coupling incorrectly connected
Check oil pressure line.
Cylinder release valve not
working
Repair cylinder
Insufficient air pressure.
Check compressed air supply to
pump is between 2.8 and 10Bar.
Air filter dirty or clogged.
Clean or Renew.
Reservoir breather plug or
screw not opened
Open breather Plug or screw as
described in section 5
Pump operates but
no pressurizes oil is
delivered
Pump fails to reach
maximum pressure
Pump delivers
pressurized oil but
load is not lifting
Piston retracts
although treadle is
not pressed on
RELEASE side
Piston fails to perform
retract stroke (single
acting cylinder)
Piston fails to perform
retract stroke (single
acting cylinder)
Pump
flow
rate
insufficient
Pump stops working
under load
