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SERVICE BULLETIN NUMBER: DATE: MODEL: SB-214-017 12/11/03 E-Tech™ (Not applicable to Mack Trucks Australia) (Supersedes bulletin SB-214-017 dated 3/14/03) WASTEGATE TURBOCHARGERS — DESCRIPTION, OPERATION AND TROUBLESHOOTING A production phase-in period for the E-Tech™ E7-460 CCRS engine began in October 2001 (beginning with engine serial No. 1R1639). A wastegate turbocharger is used on E-Tech™ E7-460 CCRS engines, whereas a standard turbocharger is used on E-Tech™ E7-460 preCCRS engines. Wastegate turbochargers allow the use of a smaller turbine housing for better performance and improved emissions at high altitudes. “Over-boosting” is prevented by the wastegate. The wastegate, which is controlled by boost pressure supplied from the inlet manifold, prevents over-boosting by opening a small port inside the turbine housing to allow a portion of the exhaust flow to bypass the turbine wheel as maximum boost pressure is reached. 1 Figure 1 — Wastegate Turbocharger SB-214-017 — Page 1 of 17 SERVICE PUBLICATIONS, ALLENTOWN, PA 18105 ©MACK TRUCKS, INC. 2003 Diaphragm-Controlled Wastegate The wastegate consists of a bypass valve located inside the turbine housing and a springloaded actuator that opens and closes the valve in response to boost pressure supplied from the inlet manifold. An air line is connected between the wastegate actuator and the inlet manifold. When boost pressure is below maximum, spring tension holds the bypass valve closed. As the engine accelerates and increases in load, the turbine wheel spins faster due to the increased flow of engine exhaust, thus increasing boost pressure. Boost pressure enters the inlet port of the wastegate actuator and pushes against the spring-loaded diaphragm. 2 Figure 2 — Exhaust Flow with Bypass Valve Closed SB-214-017 — Page 2 of 17 As boost pressure increases, spring tension that holds the bypass valve closed is overcome, and the actuator rod then opens the bypass valve. Once the valve opens, a small volume of exhaust flows through the open port in the turbine housing, bypassing the turbine wheel. With a lesser volume of exhaust driving the turbine wheel, wheel speed and boost pressure stabilize at the intended full load operating level. 3 Figure 3 — Exhaust Flow with Bypass Valve Opened E-Tech™ E7-460 CCRS Engines Beginning with V-MAC® III Step 8 Software On E-Tech™ E7-460 engines, beginning with V-MAC® III step 8 software, a barometric pressure sensor and a boost pressure sensor were incorporated into the system. 앫 Barometric Pressure Sensor — The barometric pressure sensor, which is located in the engine electronic control unit (EECU), continuously monitors ambient barometric pressure and transmits the information to the EECU. 앫 Boost Pressure Sensor — The boost pressure sensor, which is located in the inlet manifold, continuously monitors inlet manifold pressure and transmits this information to the EECU. The EECU uses the data supplied by both the boost pressure sensor and the barometric pressure sensor for fault activation and diagnostics. SB-214-017 — Page 3 of 17 Wastegate Diagnostics and Fault Activation If either a high or low boost condition is measured when compared to a target boost value, then the electronic malfunction light will illuminate, accompanied by a reduction in power (approximately 73% of maximum). Power will be restored and the electronic malfunction light will turn off when boost pressure again matches the target boost value. As an example, a wastegate malfunction would most likely be encountered during a hard pull if the bypass valve does not open properly (fault occurs). The electronic malfunction light, however, will turn off and power will be restored when no longer under a hard pull and the boost level is then normal. In these cases, illumination of the electronic malfunction light and the reduction in power will be intermittent. Checking Wastegate Actuator Operation REV Before proceeding with wastegate actuator diagnostics and possible actuator replacement, tighten the turbine housing band clamp to 96 lb-in (11N·m). If the clamp will not tighten properly, replace the clamp and tighten to 96 lb-in (11 N·m) Perform a general inspection of the wastegate actuator mounting bracket, mounting bolts actuator canister, actuator rod and wastegate lever for any damage that could result in the failure of the wastegate actuator to operate. Checking for Wastegate Actuator Diaphragm Air Leakage Use the following procedures to check the wastegate actuator diaphragm for air leakage: The following is a quick test, requiring no special equipment or measurements. This test should be the first item performed after performing the general inspection as described above under the heading “Checking Wastegate Actuator Operation.“ 1. Disconnect the air line from the wastegate actuator canister. SB-214-017 — Page 4 of 17 2. Connect an air pressure regulator and a pressure gauge to the air fitting on the actuator canister. 4 Figure 4 — Connecting Regulated Air Pressure to Wastegate Actuator 3. Repeatedly apply and remove 32–33 psi air pressure to the actuator canister and note that the actuator rod moves freely, with approximately 0.050″ (1.27 mm) of travel. Never apply more than 40 psi to the wastegate actuator canister. Doing so will result in damage to the diaphragm. 4. Listen and feel for air leakage in the area of the actuator where the actuator rod enters the canister. If application of the specified pressure to the canister fails to move the actuator rod, the usual cause is a leaking diaphragm. If it has been determined that the diaphragm is leaking, the wastegate actuator must be replaced. Install the replacement actuator kit (part No. 7536-174307). A properly adjusted and operational wastegate has only approximately 0.050″ (1.27 mm) of travel. Measuring Actuator Rod Travel If the air pressure test determined that the actuator canister diaphragm is NOT leaking, measure actuator rod as follows: SB-214-017 — Page 5 of 17 To accurately measure actuator rod travel, a dial test indicator should be used. This type of dial indicator is positioned 90 degrees to the direction of travel of the component being measured, whereas a standard dial indicator is positioned on the same plane as the component movement. A standard dial indicator can be easily used if the turbocharger has been removed from the engine, but it is difficult to use for on-engine measurement of actuator rod travel. Dial test indicators are available from most industrial or machine tool suppliers. 5 Figure 5 — Dial Test Indicator 1. Install the magnetic base of a dial test indicator at an accessible location on the engine block, and position the indicator probe against the end of the actuator rod. 6 Figure 6 — Measuring Actuator Rod Travel 2. Apply 32–33 psi to the actuator and note actuator rod travel as indicated by the dial indicator. Shut off the pressure to the actuator canister. SB-214-017 — Page 6 of 17 At 32-–33 psi, actuator rod travel should be 0.050″ (1.27 mm). If specified actuator rod travel is not achieved, refer to the diagnostic chart to determine the root cause and the corrective actions required. Troubleshooting The wastegate turbocharger is a mechanical system that operates on boost pressure delivered from the inlet manifold. Because inlet manifold boost pressure is utilized, this system is more accurate than systems where boost pressure from the turbocharger outlet is utilized. The 4-5 fault code will activate for either low or high boost pressure. When troubleshooting a 4-5 fault code, first determine if boost pressure is low or high, then proceed with the appropriate section from the following diagnostic chart. The typical cause of a 4-5 fault code is turbocharger wastegate actuator diaphragm leakage resulting in high boost pressure. When diagnosing a 4-5 fault code for high boost pressure, first determine if the actuator diaphragm is leaking by performing the test outlined under the heading “Checking for Wastegate Actuator Diaphragm Air Leakage.” If diaphragm air leakage is not the cause, proceed with the procedures outlined in the following diagnostic chart. This chart covers mechanical problems that may develop with the wastegate. For electronic problems that may activate a 4-5 fault code, refer to service bulletin SB-221-029. SB-214-017 — Page 7 of 17 Condition REV Possible Cause Low Boost — Wastegate remains 1. Broken wastegate linkage or open or partially open, resulting in wastegate mechanism. poor throttle response/acceleration with black smoke possible at low 2. Wastegate actuator mounting bracket bent. engine speeds, high loads or during transient operation. This condition will illuminate the 3. Corrosion of the bypass valve electronic malfunction light, reduce crankarm pivot axle where it engine power and log a 4-5 fault passes through the turbine code. housing, causing the bypass valve to remain open (during extended periods of storage, the pivot axle should be well oiled to prevent corrosion). 4. Wastegate crankarm stuck open. High Boost — Wastegate remains 1. Tampering with system by disclosed, resulting in boost pressure connecting and plugging being too high at high speeds/high boost air line, or by disconloads, with the possibility of necting actuator rod from the causing a blown cylinder head crankarm. gasket or cylinder head gasket leakage. This condition will 2 Leak in boost air line between illuminate the electronic inlet manifold and wastegate malfunction light, reduce engine actuator. power and log a 4-5 fault code. 3. Leaking or failed actuator diaphragm. Correction 1. Replace actuator with kit part No. 7536-174307. 2. Replace actuator mounting bracket (included in actuator kit part No. 7536-174307). 3. Follow the procedures outlined under the heading “Freeing a Corroded Crankarm Pivot Axle.” 4. Follow the procedures outlined under the heading “Freeing a Corroded Crankarm Pivot Axle.” If the problem cannot be resolved, replace wastegate turbocharger. 1. Inspect for evidence of possible tampering and correct as required. 2. Check air line between inlet manifold and wastegate actuator and replace line as required. 3. Perform a general inspection of the wastegate actuator components. If no problem is evident, perform the “Checking for Wastegate Actuator Diaphragm Air Leakage” procedures outlined on page 4. If air leakage is found, replace actuator with kit part No. 7536-174307. 4. Corrosion of the bypass valve crankarm pivot axle where it passes through the turbine housing, causing the bypass valve to remain closed (during extended periods of storage, the pivot axle should be well oiled to prevent corrosion). 4. Follow the procedures under the heading “Freeing a Corroded Crankarm Pivot Axle.” 5. Wastegate crankarm stuck closed. 5. Follow the procedures under the heading “Freeing a Corroded Crankarm Pivot Axle.” If the problem cannot be resolved, replace wastegate turbocharger. SB-214-017 — Page 8 of 17 REV Effective March 2003, replacement actuator kit (part No. 7536173566) became available through the MACK Parts System. Beginning 3/14/03, replacement of the complete turbocharger because of a defective wastegate actuator assembly will not be covered by warranty. Effective December 2003, actuator kit part No. 7536-173566 was replaced by kit part No. 7536-174307. The new actuator kit has an improved actuator. If the vehicle will be parked for a long period of time, the bypass valve crankarm pivot axle that passes through the turbine housing may become corroded and cause the rod to seize. During extended periods of storage, the pivot axle should be well oiled to prevent corrosion. Wastegate turbochargers have the wastegate actuator rod adjusted to specifications when assembled by Borg-Warner Turbocharger Systems. No further adjustment is necessary on an existing turbocharger. When replacing an actuator, the actuator rod end must be adjusted to provide proper rod travel at a specific air pressure. These adjustment procedures are outlined in this bulletin under the heading “Wastegate Actuator Replacement.” Tampering with the wastegate mechanism in any way with the intent on defeating proper operation of the system will result in fault activation, a reduction in engine power and erratic performance. Wastegate Actuator Replacement If diagnostic procedures indicate that the wastegate actuator must be replaced due to a leaking canister diaphragm or a bent actuator rod, an actuator replacement kit (part No. 7536-174307) is available through the MACK Parts System. Procedures for replacing the wastegate actuator are as follows: The wastegate actuator replacement instructions outlined in this bulletin supersede any instructions supplied with the actuator replacement kit. SB-214-017 — Page 9 of 17 Actuator Removal 1. Disconnect the air line from the wastegate actuator canister. 2. Connect an air line, air pressure regulator and air pressure gauge to the air fitting on the actuator canister. 7 Figure 7 — Connecting Regulated Air Pressure to Wastegate Actuator 3. Adjust the pressure regulator to apply 33 psi to the wastegate actuator. 4. Remove and discard the snap ring from the wastegate crankarm pin. 8 Figure 8 — Removing Snap Ring from the Wastegate Crankarm Pin 5. Remove the actuator rod from the crankarm pin. SB-214-017 — Page 10 of 17 If the actuator diaphragm is leaking badly enough that the rod will not move forward when pressure is applied, the actuator can be removed by removing the mounting bracket and actuator as an assembly. 6. Reduce air pressure to 0 psi, then disconnect the air line, pressure gauge and regulator from the canister air fitting. Before removing the canister, note the orientation of the air fitting. The canister must be reinstalled with the fitting in the same position. 9 Figure 9 — Canister Air Fitting Orientation 7. Remove the nuts that secure the canister and heat shield to the mounting bracket, then remove the canister and the heat shield. 8. Remove the two bolts that secure the bracket to the turbine housing. These mounting bolts may be reused, but there are two bolts included in the actuator replacement kit (part No. 7536-174307) should the existing mounting bolts be unusable. Install the new mounting bracket (included in the kit) to the turbine housing. Do not tighten the mounting bolts at this time. Merely thread the bolts into the mounting holes a couple of turns. SB-214-017 — Page 11 of 17 Actuator Installation REV 1. Screw the jam nut included in the kit all the way onto the threaded actuator shaft until the nut reaches the unthreaded portion of the shaft, then install the actuator rod end. As the starting point from which to begin the actuator adjustment process, the measurement between the top of the rod end and the actuator canister should be approximately 4″ (101.6 mm). 10 Figure 10 — Actuator Installation Dimension 2. With the air fitting on the canister oriented in the same position as the original canister, place the heat shield on the new actuator assembly and install on the mounting bracket. Use the new locknuts included in the kit, and tighten the nuts to 65 lb-in (7 N·m). 3. Connect the air line, regulator and pressure gauge to the air line fitting located on the actuator canister. 4. Adjust the pressure regulator to apply 33 psi to move the actuator rod forward, then place the rod end over the wastegate crankarm pin. Reduce the air pressure to 0 psi. DO NOT pry the actuator rod in order to install the rod end over the crankarm pin. Doing so can damage the actuator diaphragm. The mounting bracket bolts should be very loose to allow enough play in the actuator assembly so that the rod end can be easily installed onto the crankarm pin. 5. Tighten the actuator mounting bracket bolts to 145 lb-in (16 N·m). 6. Determine the actuation calibration reading and adjust the actuator rod as outlined in the following instructions. SB-214-017 — Page 12 of 17 Determining Actuator Calibration Reading and Adjusting Actuator Rod Travel A good quality air pressure gauge graduated in 1.0 psi increments is acceptable for wastegate actuator calibration. These instructions are based on observing a range of 32–33 psi, and where a specification of 32.5 psi is given, the intention is that the pressure gauge pointer is half-way between the 32 and 33 psi graduations. 1. Install the magnetic base of a dial test indicator at an accessible location on the engine block and position the indicator probe against the end of the actuator rod. The travel of the dial indicator probe must align with the travel of the rod or false measurement will result. 11 Figure 11 — Dial Test Indicator Installation for Measuring Rod Travel 2. With the air line, regulator and air pressure gauge connected to the actuator canister, slowly turn the pressure regulator knob to increase air pressure while observing the dial indicator. Increase air pressure until actuator rod travel is 0.050″ (1.27 mm) as indicated by the dial indicator. At 0.050″ (1.27 mm) of travel, note and record the pressure reading indicated on the pressure gauge. Never apply more than 40 psi to the wastegate actuator canister. Doing so will result in damage to the diaphragm. 3. Slowly turn the pressure regulator knob to decrease air pressure to 0 psi. Repeat step 1 above and again note and record the pressure reading indicated on the pressure gauge. Slowly turn the pressure regulator knob to decrease air pressure to 0 psi. The SB-214-017 — Page 13 of 17 pressure reading obtained in this test is the Actuator Calibration Reading. Depending upon the Actuator Calibration reading, adjust the actuator rod end as follows: 앫 Actuator Calibration Reading of 32.5 psi — a. Install the new snap ring included in the kit on the crankarm pin. b. Tighten the jam nut against the rod end of the actuator. When tightening the jam nut, use a small adjustable wrench on the flat portion of the rod end to hold the rod end and prevent it from turning. 앫 Actuator Calibration Reading above 33 psi — a. Apply 32–33 psi to the canister to move the actuator rod forward, then remove the rod end from the crankarm pin. Do not pry the actuator rod from the crankarm pin. Doing so will damage the actuator diaphragm. b. Decrease pressure to 0 psi. c. Turn the rod end counterclockwise. The actuator calibration reading will decrease approximately 0.2 psi for every 1/2 turn of the rod end. d. Increase air pressure to move the actuator rod forward, then install the rod end over the crankarm pin. Decrease pressure to 0 psi. e. Slowly turn the pressure regulator knob to increase air pressure while observing the dial indicator. Increase air pressure until actuator rod travel is 0.050″ (1.27 mm). At 0.050″ (1.27 mm) of travel, note and record the pressure reading indicated on the air pressure gauge. Decrease air pressure to 0 psi. f. Repeat step “e” above, and again note and record the pressure reading indicated on the pressure gauge. Slowly turn the pressure regulator knob to decrease air pressure to 0 psi. g. If the Actuator Calibration Reading is still above 33 psi, repeat steps “a” through “f” above. h. When an Actuator Calibration Reading of 32.5 ±0.5 psi is obtained, place the rod end over the crankarm pin, then install the new snap ring included in the kit. Tighten the jam nut against the rod end of the actuator. When tightening the jam nut, use a small adjustable wrench on the flat portion of the rod end to hold the rod end and prevent it from turning. SB-214-017 — Page 14 of 17 앫 REV Actuator Calibration Reading Below 32 psi — a. Apply 32–33 psi to the canister to move the actuator rod forward, then remove the rod end from the crankarm pin. Do not pry the actuator rod from the crankarm pin. Doing so will damage the actuator diaphragm. b. Decrease pressure to 0 psi. c. Turn the rod end clockwise. The actuator calibration reading will increase approximately 0.2 psi for every 1/2 turn of the rod. d. Increase air pressure to move the actuator rod forward, then install the rod end over the crankarm pin. Decrease pressure to 0 psi. e. Slowly turn the pressure regulator knob to increase air pressure while observing the dial indicator. Increase air pressure until actuator rod travel is 0.050″ (1.27 mm). At 0.050″ (1.27 mm) of travel, note and record the pressure reading indicated on the air pressure gauge. Decrease air pressure to 0 psi. f. Repeat step “e” above, and again note and record the pressure reading indicated on the pressure gauge. Slowly turn the pressure regulator knob to decrease air pressure to 0 psi. g. If the Actuator Calibration Reading is still below 32 psi, repeat steps “a” through “f” above. h. When an Actuator Calibration Reading of 32.5 ± 0.5 psi is obtained, place the rod end over the crankarm pin, then install the new snap ring included in the kit. Tighten the jam nut against the rod end of the actuator. When tightening the jam nut, use a small adjustable wrench on the flat portion of the rod end to hold the rod end and prevent it from turning. 4. After the actuator rod has been properly adjusted and the jam nut tightened, remove the dial test indicator. 5. Disconnect the air line, pressure gauge and regulator from the canister air fitting. 6. Reconnect the air line from the inlet manifold to the fitting on the actuator canister. Make sure the hose is not kinked and that the hose does not rub against any part of the engine. SB-214-017 — Page 15 of 17 Freeing a Corroded Crankarm Pivot Axle 1. Remove the snap ring that secures the actuator rod end to the crankarm pin. 2. Disconnect the air line from the actuator canister. 12 Figure 12 — Removing Actuator Rod Snap Ring 3. Remove the bolts that secure the wastegate actuator mounting bracket to the turbine housing. 4. Carefully remove the actuator rod end from the crankarm pin. DO NOT attempt to pry the rod from the crankarm pin without removing the actuator mounting bracket bolts. Doing so will damage the actuator diaphragm. 5. Remove the cover plate from the bypass valve access port. 13 Figure 13 — Bypass Valve Access Port Cover Plate SB-214-017 — Page 16 of 17 6. Spray the pivot axle with penetrating oil (such as WD-40 or an equivalent product) from the outside of the turbine housing, and also on the inside of the housing through the bypass valve access port. 14 Figure 14 — Spray Penetrating Oil on Pivot Axle 7. Allow the penetrating oil to soak for a period of time. 8. After allowing the oil to soak for a sufficient period of time, begin moving the crankarm back and forth while spraying the pivot axle with penetrating oil. Continue until free movement of the pivot axle is obtained. 9. Install the actuator and mounting bracket onto the turbine housing, then loosely install the mounting bolts. DO NOT tighten the mounting bolts at this time. 10. Connect an air line, pressure gauge and a regulated air supply to the air fitting on the canister. 11. Slowly turn the regulator to apply pressure to the canister so that the actuator rod begins to extend, then place the rod end over the crankarm pin. DO NOT apply more than 40 psi to the canister. Damage to the actuator diaphragm can occur. 12. Reduce air pressure to 0 psi. 13. Install the snap ring to secure the rod end to the crankarm pin. 14. Tighten the actuator mounting bracket bolts to 145 lb-in (16 N·m). 15. Remove the regulated air supply from the actuator canister, then reconnect the air line. 16. Install the cover plate on the bypass valve access port and tighten the bolts to 145 lb-in (16 N·m). SB-214-017 — Page 17 of 17
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