SPX LeakMaster 6525 Manual Del Operador página 13

Vacuum and Induction Leaks
EGR Valve Leaks
The exhaust gas recirculating valve is at the heart of
the emission control system. Since the EGR valve
operates in such a hostile environment, it is always
susceptible to leakage. During a normal test for
vacuum leaks, the EGR valve will be exposed to
smoke and may show leaks at the seat, diaphragm, or
even the base gasket.
If smoke is seen exiting the EGR valve, disconnect the
vacuum supply line, and introduce smoke directly into
the valve. This will verify if the diaphragm is leaking,
or if the valve is leaking at the seat.
Smoke may also be used to check EGR ports for
restriction. Open or remove the valve, and introduce
smoke through the tail pipe to verify these ports are
open.
Idle Motors and Solenoid Leaks
A small leak in an idle motor or solenoid component
can make an engine idle rough or stall. Leaks in these
components are usually found during a normal vacuum
leak test. It is not unusual to find base gaskets and
o-rings leaking in and around motors and solenoids.
Brake Booster Leaks
A leaking vacuum brake booster not only affects
engine performance like other types of vacuum
leaks, but more importantly, it can seriously affect the
stopping power of the vehicle.
Pressing on the brake pedal during this test
will falsify the test results.
1. Disconnect the vacuum supply line and the check
valve from the brake booster.
2. Insert the smoke supply nozzle into the brake
booster, and press the tester's remote button once
to begin introducing smoke.
3. If the tester's flow meter indicates flow, the brake
booster has a leak.
4. Under the hood, look for smoke exiting around the
crimped area of the booster canister. Also look for
smoke inside the vehicle under the dash.
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Tech Tips
Testing the EGR Pintle Shaft – This will help
you diagnose a good or bad EGR valve and
other "metered" leaks.
1. Do not cap off any part of the engine –
leave it in a normal operating state (but
not running). Insert the LeakMaster supply
hose into a direct vacuum manifold source,
such as a brake booster hose or PCV. Press
the remote button on the LeakMaster. Watch
for smoke to escape from the EGR valve. If
you see a lot of smoke, the valve is bad; no
smoke, move on to the next step.
2. Cap off the intake using one of the cap plugs
supplied with the LeakMaster. Insert the
exhaust cone into the tailpipe. (The hose
on the exhaust cone should be plugged with
the cap plug provided.) Now that the system
is sealed, press the remote button and
watch for smoke. A small amount of smoke
indicates an acceptable EGR valve.