ENGINE DIVISION SERVICE MANUAL
deposits from pintle and seat, if necessary.
To clean deposits from pintle and seat of EGR valve, use
a sand blast type spark plug cleaner and the following
Prepare spark plug cleaner by installing rubber
adapter with 22 mm (7/8") hole over cleaning
(blast) port. Do not install metal adapter clamp
Insert pintle of EGR valve through hole in rubber
plug cleaner adapter.
Holding EGR valve tightly down adapter, apply
sand blast to clean pintle.
performing cleaning operation.
Fig. 50 Cleaning EGRH Valve
After cleaning exposed pintle, hold EGR valve in
both hands and press in diaphragm to retract
valve pintle into valve housing. Use a 25 mm
(1") long bolt (3/4" long for dual diaphragm
valves) to hold pintle in retracted position. Apply
masking tape to cover outlet port of valve.
With pintle opening of valve aligned with hole in
cleaning adapter, hold EGR valve down tightly
against adapter and apply sand blast to clean
interior of valve housing and valve seat.
After cleaning, blow all excess sand from interior of
valve housing and remove bolt.
Recheck valve for proper operation and seating.
Replace with new valve, if necessary.
15. Check EGR System with Functional Test and Clean or
Replace, If necessary. (V-345 and V-392 Engines
Perform EGR System Functional Test as follows:
Operate engine until it reaches normal operating
Shut off engine. Connect tachometer. Connect
vacuum pump with vacuum gauge to EGR system
vacuum hose at carburetor.
Plug fitting at carburetor.
With tachometer installed, operate all engines at
Apply specified vacuum (see Emission Control
System Tune-Up Specifications).
Fig. 51 Complete EGR System Test
Specifications for engine speed drop when vacuum is
applied. This procedure checks not only the EGR
valve but the intake manifold and related passages
CGES-215 Page 28
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