Testing Fuel Pressure - Komatsu Galeo PC138US-8 Shop Manual

SEN02458-01

Testing fuel pressure

a Testing tools for fuel pressure
Symbol Part No.
799-101-5002 Hydraulic tester
1
790-261-1204 Digital hydraulic tester
F 795-471-1450 Adapter (8 x 1.25 mm)
2
07005-00812
3 799-401-2320 Gauge
k
Stop the machine on a level ground and
lower the work equipment to the ground.
a Test only the fuel pressure in the low-pressure
circuit from the priming pump through the fuel
main filter to the supply pump and the return
circuit from the supply pump/common rail/
injector to fuel tank.
k
Since the pressure in the high-pressure cir-
cuit from the supply pump through the
common rail to the injector is very high, it
cannot be tested.
1. Testing pressure in fuel low-pressure cir-
cuit
1) Open the engine hood and remove fuel
pressure pickup plug (1) from the fuel
main filter.
2) Install adapter F2 and nipple [1] of hydrau-
lic tester F1 and connect them to oil pres-
sure gauge [2]
a Use the oil pressure gauge of 2.5 MPa
{25 kg/cm
16
Part name
O-ring
2
}.
1
3) Run the engine at high idle and test the
pressure in the fuel low-pressure circuit.
a If the pressure in the fuel low-pres-
sure circuit is in the following range, it
is normal.
Engine speed
At high idle
4) After finishing test, remove the testing
tools and return the removed parts.
3
30 Testing and adjusting
Fuel pressure
-49 – 0 kPa
{-0.5 – 0 kg/cm
Fuel pressure pickup plug:
7.8 – 9.8 Nm {0.8 – 1.0 kgm}
PC138US, USLC-8
2
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