Turbocharger Wastegate - Craftsman professional 14005 Manual Del Operador

SYSTEM OPERATION
The turbocharger wastegate (exhaust bypass valve)
limits the amount of boost (intake manifold pres-
sure) created by the turbo. When intake manifold
pressure becomes too high, the wastegate opens
to allow some exhaust to bypass the turbo. This
reduces the turbo boost.
Most turbo wastegate actuators operate using a
mechanical spring and diaphragm design. Under
normal operating conditions, the spring holds the
wastegate valve closed, and all exhaust is directed
to the turbocharger. A small tube connects the
wastegate actuator to the intake manifold or turbo
air outlet. When boost pressure becomes too high, it
pushes against the diaphragm until it overcomes the
spring force, causing the wastegate to open.
Testing the function of the wastegate and wastegate
actuator involves attaching the hand pump to wa-
stegate and applying pressure.
SERVICE PROCEDURES
Follow the procedures below to diagnose a turbo- or
super-charger wastegate and actuator:
Cold Test for Visual Movement
1) Locate the wastegate actuator, and inspect it for
damage. Check the pressure hose for visible leaks
or cracks. Replace if necessary.
2) Disconnect the pressure hose from the wastegate
actuator and connect the hand pump in its place.
3) Use the pump to apply pressure according to the
manufacturer's specification.
4) Watch for the control rod to move and then hold
its position.
5) If the rod doesn't move or hold its position, or if
the pressure leaks down as indicated by the gauge
on the hand pump, replace or repair the wastegate
actuator.
6) If no leak is found, disconnect the actuator rod
and move the wastegate flapper lever to determine
if it is stuck or seized.
7) If it does not move freely, the wastegate should
be replaced or repaired.

turbocharGer wasteGate

Idle Test
8) Start with the exhaust system cold.
9) Disconnect the pressure hose from the wastegate
actuator and connect the hand pump in its place.
10) Start the engine and allow it to idle.
11) After a short time, the exhaust inlet to the wa-
stegate should warm up, but the bypass line out of
the wastegate should remain cool.
12) If the bypass line heats up at this point, exhaust
is leaking past the wastegate, and the wastegate
should be replaced or repaired.
13) Use the pump to apply pressure to open the
wastegate according to the manufacturer's specifica-
tion.
14) Feel the bypass line. It should begin to warm up
as the wastegate opens.
15) If not, the wastegate is stuck closed and should
be replaced or repaired.
16) Once testing is complete, bleed the pressure
from the pump and watch for the wastegate to
close.
Bench Testing
A hand pump should be used to bench testing the
turbocharger wastegate, and adjusting the control
arm after replacement or repair. Follow the manu-
facturer's procedures for performing these precision
tests and adjustments.
Pressure
Connection
FIGURE 7: TURBOCHARGER
12
Wastegate Actuator