Service Manual

ISB, ISBe and QSB (Common Rail [...] Injector
Section 6 - Injectors and Fuel Lines - Group 06 Page 6-71
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Isolation of the fuel rail pressure relief valve flow from the
injector return flow requires the use of the fuel rail
pressure relief valve flow tester kit, Part Number 4918295.
Remove the banjo bolt from the fuel rail pressure relief
valve.
Install the fuel rail pressure relief valve fuel drain hose
onto the pressure relief valve using the banjo bolt supplied
in the tester kit.
Install the cap supplied in the pressure relief valve tester
kit onto the existing banjo, to cap off the pressure relief
valve fuel drain line.
Measurement of injector return flow requires the use of a
fuel system leak tester, Part Number 4918354. The fuel
system leak tester contains Part Numbers: 4918297,
4918433, and 4918434.
Remove the banjo bolt from the fuel drain line at the fuel
return manifold. (This is the inline banjo fitting). Install a
cap, Part Number 4918297, onto the banjo bolt to prevent
fuel flow to the return manifold.
To prevent high pressure fuel pump return flow from
entering the injector return flow, remove the fuel return
line quick-disconnect on the injector pump.
Install a fuel drain hose with a female quick-disconnect,
Part Number 4918434, onto the high pressure fuel pump
and drain into a bucket.
Insert a fuel drain hose with male quick-disconnect, Part
Number 4918433, into the removed fuel drain line. Place
the end of the fuel drain hose into a graduated cylinder,
Part Number 3823705.
Marine Applications
NOTE: The fuel return manifold on marine engines is
located on the side of the engine block, in front of the
ECM.
Follow the fuel drain line from the injector return port at
the back of the cylinder head to the fuel return manifold.