ENGINE SYSTEMS 57
Figure 50 Brake pressure relief valve in
high-pressure oil rail
1. Front of engine
2. Brake pressure relief valve
The ECM removes the ground source from the
brake shutoff valve to deactivate the engine brake.
Residual brake gallery pressure initially bleeds from
the actuator bore. When brake gallery pressure
reaches 1000 psi, the brake pressure relief valve
opens, and oil drains back to sump.
EGES-265-2
Read all safety instructions in the "Safety Information" section of this manual before doing any procedures.
Follow all warnings, cautions, and notes.
© 2009 Navistar, Inc.