Centinel System – Repair Manual – 010-050   Turbocharger Wastegate Actuator

Most Signature™, ISX, and QSX15 engine models are equipped with wastegate turbochargers to limit the peak boost level and increase engine response at low rpm.

The wastegate actuator hose takes boost pressure from the intake manifold through the control valve to the wastegate capsule.

Inspect the wastegate actuator hose for cracks or holes.

Replace the hose if damaged.

CAUTION  A bent wastegate mounting bracket, actuator rod, or lever can cause improper operation.

Inspect the wastegate mounting bracket, actuator rod, and lever for damage.

If the wastegate mounting bracket, actuator rod, or lever is bent, it
must be replaced.

WARNING  Exhaust and turbocharger components could be hot. Use caution and wear protective clothing when handling these components.

To verify the wastegate actuator travel, install Service Tool, Part Number 3165168, on the wastegate cover with the magnetic base and the dial indicator resting on the end of the actuator end link.

Disconnect the air supply line from the wastegate actuator and install the air line from the air control valve, Part Number ST-990-40, to the wastegate actuator.

Install the male quick-connect fitting, Part Number 3377244 (1), into the air control valve, Part Number ST-990-40 (2), to the wastegate actuator for use with the Compuchek™ quick-disconnect fitting, Part Number 3376859 (3) attached to the pressure transducer, Part Number 3164491 (4).

Connect the pressure adapter, Part Number 3164491 (1), to the multimeter, Part Number 3164488 (2).

Air leaks should
not be detected through a functional wastegate capsule.

Connect the air supply to the control valve. Apply regulated air pressure of 100 kPa [14.5 psi] to the wastegate actuator to measure the travel.

Cycle the air pressure to the actuator assembly several times to work the system. Do
not exceed 100 kPa [14.5 psi].

Measure the actuator rod for correct travel. If the actuator travel is
not within the specifications, the wastegate
must be adjusted. If adjustment is required, remove the turbocharger.

To make sure an accurate measurement is obtained, it is essential to use the specified tools and procedures.

• Remove the turbocharger. Refer to Procedure 010-033 (Turbocharger) in Section 10.

To obtain an accurate measurement, do
not remove the wastegate valve cover or take the measurement from the top of the capscrew that secures the wastegate valve cover.

Use a micrometer depth gauge. To made a measurement from the face of the wastegate valve cover to the end of the wastegate actuator end link. Do
not apply air pressure to the wastegate actuator.

If the wastegate wear measurement is less than 25.654 mm [1.010 in] then the turbocharger wastegate actuator can be recalibrated and the turbocharger returned to service. If the wastegate wear measurement is greater than 25.654 mm [1.010 in], replace the turbocharger turbine housing.

Remove the retaining clip from the control lever.

WARNING  Wear appropriate eye and face protection when using compressed air. Flying debris and dirt can cause bodily injury.

CAUTION  Be careful not to bend the control lever.

Air Regulator with Pressure Gauge

Slowly apply regulated air pressure to the boost capsule. A maximum of 310 kPa [45 psi] can be used. Disconnect the boost capsule actuator rod end from the turbocharger wastegate lever rod when the rod is loose on the lever.

NOTE: If the boost capsule diaphragm material is ruptured and will
not hold air pressure, it can be necessary to manually pull the control rod outward in order to overcome boost capsule spring-tension for removal of the control rod from the turbocharger wastegate lever pin while applying air pressure.

Disconnect the control rod from the turbocharger wastegate lever pin.

Loosen the boost capsule mounting capscrews, disconnect the wastegate actuator hose, and remove the assembly from the mounting bracket.

A new hose clamp is required to install the signal line.

Disconnect the actuator hose from the wastegate actuator by cutting the crimped hose clamp.

Air leaks should
not be detected through a functional wastegate capsule.

Connect clean regulated air pressure and a pressure gauge to the actuator.

Apply 100 kPa [14.5 psi] to make sure the wastegate is functioning properly.

Measure the actuator rod for correct travel. If the actuator travel is
not within the specifications, the wastegate
must be calibrated.

If no actuator travel is observed, inspect the wastegate valve for seizure or damage.
Refer to Procedure 010-055 (Turbocharger Wastegate Valve Body) in Section 10.

CAUTION  If there is a turnbuckle with an adjusting link, do NOT adjust the piston guided actuator by turning the rod of the actuator. This will damage the rubber diaphragm inside the actuator. The knurled turnbuckle on the new end adjusting link must be used.

Leave the setting pressure air supply connected to the wastegate capsule.

Loosen the actuator end-link locknut.

CAUTION  To reduce the possibility of breaking the wastegate pivot pin, use a wrench on the end link to support it while loosening and/or tightening the actuator end-link locknut.

Remove the actuator end-link retaining clip.

Remove the actuator end link from the wastegate lever.

CAUTION  If there is a turnbuckle with an adjusting link, do NOT adjust the piston guided actuator by turning the rod of the actuator. This will damage the rubber diaphragm inside the actuator. The knurled turnbuckle on the new end adjusting link must be used.

Adjust the length of the end link by rotating to obtain nominal travel.

After adjusting is completed, tighten the end-link locknut against the end link.

Cycle the air pressure to the wastegate actuator several times to work the system.

Verify the actuator travel is within specifications.

Install the retaining clip.

Disconnect the regulated air pressure line from the wastegate actuator.

If a new actuator is being installed, install the adjusting end link onto the shaft of the precalibrated wastegate actuator assembly.

Thread the new end link several turns onto the shaft of the new pre-set actuator assembly.

Install the new pre-set actuator assembly onto the bracket, so the actuator clamp is in position to give access to the capscrew.

If the capscrew can
not be reached, remove the actuator and carefully rotate the actuator assembly until the capscrew is accessible.

Fit the actuator assembly and nuts.

With the valve held closed (pushed toward the compressor housing), rotate the end link until the hole aligns with the crank-arm pin, so the end link can be fitted over the pin without using force.

The setting is correct if, by rotating the end link
clockwise an extra half-turn, the end link can no longer be fitted onto the crank-arm pin.

Fit the new e-clip (snap ring) provided in the kit.

Tighten jam-nut against end link.

Remove the actuator clamp.

• Install the turbocharger.
  Refer to Procedure 010-033 (Turbocharger) in Section 10.

• Operate the engine and check for proper operation.