Testing Fuel Pressure - Komatsu ecot3 PC300LC-8 Shop Manual

SEN02625-06

Testing fuel pressure

Symbol Part number
799-101-5002 Hydraulic tester
1
790-261-1204 Digital hydraulic tester
6732-81-3170
2
G
6215-81-9710 O-ring
3 799-401-2320 Gauge: 1.0 MPa {10 kg/cm
795-790-1500
4
799-201-1201
a Fuel pressure shall be checked only in the fol-
lowing 2 circuits. Negative pressure circuit be-
tween the fuel supply connector and feed pump
inlet and the low pressure circuit from the feed
pump through the fuel main filter and up to the
supply pump.
k
Measurement in the high-pressure circuit is
not available because of very high pressure
generated in this circuit covering the supply
pump through the common rail to the fuel in-
jector.
1. Measuring pressure in the fuel negative pres-
sure circuit (fuel supply connector)
1) Remove fuel pressure pickup plug (1) of the
fuel supply connector.
2) Connect adapterG2 and fuel vacuum gauge
G4.
20
Part name
Adapter
o
(10 × 1.0 mm R1/8)
Fuel vacuum gauge
2
}
3) Run the engine at high idle and measure the
pressure in the fuel negative pressure circuit.
a If the pressure in the fuel negative pres-
sure circuit is in the following range, it is
normal.
Standard pressure value in the fuel nega-
q
tive pressure circuit (fuel supply connec-
tor) Max. 27.1 kPa {Max. 203 mmHg}
4) After finishing measurement, remove the
measuring tools and return the removed
parts.
Fuel pressure pickup plug:
q
2. Measuring pressure in the fuel negative pres-
sure circuit (supply pump)
1) Remove fuel pressure pickup plug (2) of the
supply pump.
2) Connect adapter G2 and fuel vacuum gauge
G4.
30 Testing and adjusting
20 - 22 Nm {2.0 - 2.2 kgm}
PC300, 350-8