FSB 237-021v2 Service Bulletin/Repair Instructions

Field Service Bulletin

Trucks
Mack Trucks

Greensboro, NC USA
Date
Group
No.
Release
Page
5.2021
237
021
02
1(10)
Valve, Common Rail, Removal

AN, CHU, CXU, GR, GU, PI, MRU, LR, TE

MP7, MP8
FSB 237-021, Valve, Common Rail, Remove

(May 2021)

Some MACK vehicles built with MP7 or MP8 engines between 11/14/2016 and 05/04/2020

may experience internal leakage or an electrical fault of the Electronic Pressure Relief Valve

(ePRV).
•
If the DTC below is present or diagnostic testing leads to replacing the ePRV for internal

leakage, perform the repair procedure outlined in this FSB to install the ePRV delete kit

and run accessory kit.
DTC list:
•
P009B-13, Fuel Pressure Relief Control Circuit Open
Required Parts

Part Number
Description
Quantity
85156544
EPRV delete kit
1
Part Number
Description
Quantity
USA17, USA18, USA19
Accessory kit 85156014
1
Part Number
Description
Quantity
23488937
Pressure Sensor, F2

Common Rail
1
23502057
Wiring Harness, Rear
1
Required software
If Applicable Parts

(Reference Step 18)

11L Engines
PV729-FSB237-021_M
USA156854295
Mack Trucks

Field Service Bulletin
Date

5.2021
Group
No.
Release
237
021
02
13L Engines

Part Number
Description
Quantity
23488939
Pressure Sensor, F2

Common Rail
1
23502054
Wiring Harness, Rear
1
Note: Running this kit without removing the ePRV will result in adverse vehicle affects.
Procedure

You must read and understand the precautions and guidelines in Service Information,

Function Group 20, "Engine Safety Practices" before performing this procedure. If you are

not properly trained and certified in this procedure, ask your supervisor for training before

you perform it.

NOTE: Information is subject to change without notice. Illustrations are used for reference

only and can differ slightly from the actual vehicle being serviced. However, key

components addressed in this information are represented as accurately as possible.
CAUTION

Risk of material damage.

Risk of impurities being introduced into the fuel system.

Ensure conditions of maximum cleanliness when carrying out any work on the fuel system.
CAUTION

Risk of skin injury.

High fuel pressure.

The injection system may be pressurised. When working on the injection system, remove

the first part cautiously.
CAUTION

Risk of skin injury.

Grease, oil and chemical substances can cause skin and eye injuries. Oils and grease can

cause acne and eczema. A used lubricant is more harmful than an unused lubricant.

Protective equipment such as gloves and eye protection must be used when working with

grease, oils and chemical substances.
Page

2(10)
Mack Trucks

Field Service Bulletin
Date

5.2021
Group
No.
Release
237
021
02
1 Refer to IMPACT document ID: 2115-03-02-02 Valve Cover, Replacement for valve

cover removal procedure.

2 Loosen the cap nuts.

3 Remove and discard the pipe.
T2170571
4 Disconnect the connector.
T2170572
Page

3(10)
Mack Trucks

Field Service Bulletin
Date

5.2021
Group
No.
Release
237
021
02
5 Clean the area around the fitting.

6 Remove the fitting and seal.
T2170573
7 Install the seal and plug in the cylinder head.

Tightening torque

Cylinder head, plug
36± 6 lbf-ft.

(50 ± 8 Nm)
T2170574
Page

4(10)
Mack Trucks

Field Service Bulletin
Date

5.2021
Group
No.
Release
237
021
02
8 Install the tool. 88800634

9 Remove the valve.

Note: Use a spanner as a counterhold to prevent the common rail brackets and pressure

pipes from being loaded during component removal and installation.
T2170575
T2170576
CAUTION

Risk of personal injury.

Loose particles can spatter up and injure the eyes. Work with compressed air can cause

hearing impairment.

Always wear safety goggles and hearing protection when working with compressed air.
Page

5(10)
Mack Trucks

Field Service Bulletin
Date

5.2021
Group
No.
Release
237
021
02
10 Install the protecting plug.

Required material

Protecting plug
88800527
11 Clean the threads.

Note: Leave the protecting plug in place until installing the common rail plug.
T2170577
12 Remove the protecting plug.
Page

6(10)
Mack Trucks

Field Service Bulletin
Date

5.2021
Group
No.
Release
237
021
02
13 Install the plug in the rail.

Note: Do not use locking fluid or thread sealant.

14 Torque tighten the plug.

Tightening torque

Common rail, plug
92± 7 lbf–ft.

(125 ± 10 Nm)
T2170578
Note: Cap is not required to seal the common rail where the drain pipe connected.
T2170576
Note: Use a spanner as a counterhold to prevent the common rail brackets and pressure

pipes from being loaded during component removal and installation.

15 Cut the harness.

16 Remove connector and harness.

Note: Do not tape or seal the end of the harness.
Page

7(10)
Mack Trucks

Field Service Bulletin
Date

5.2021
Group
No.
Release
237
021
02
T2170579
17 A product improvement has been made to the Fuel Rail Pressure Sensor (FRPS) and its

wiring harness. A visual Inspection of the FRPS electrical connector will indicate which

sensor and wiring harness is on the vehicle.
T2170580
Page

8(10)
Mack Trucks

Field Service Bulletin
Date

5.2021
Group
No.
Release
237
021
02
18 Inspect the FRPS, if the Old Style Connector is found (displayed above with red X),

replace the sensor and wiring harness per Impact Instructions listed below. If the New

Improved Connector is found, No further action is needed and proceed to next step.

1. Refer IMPACT document ID: 2373-03-03-06 Pressure Sensor, Common Rail,

Replacement, Valve Cover Removed for pressure sensor replacement.

2. Refer IMPACT document ID: 2861-03-03-03 Wiring Harness, Injector, Replacement

(Rear), Valve Cover Removed for injector wiring harness replacement.

19 Refer to IMPACT document ID: 2115-03-02-02 Valve Cover, Replacement for valve

cover install procedure.

20 Using PTT Operation 1700-22-03-06 Program accessory kit: 85156014
Page

9(10)
Mack Trucks

Field Service Bulletin
Date

5.2021
Group
No.
Release
237
021
02
Reimbursement

This repair may be eligible for reimbursement if a product

failure was experienced within time and mileage limits of

the applicable Warranty coverage. Reimbursement is

obtained via the normal claim handling process.
UCHP

Reimbursement
Claim Type (used only when uploading from the Dealer Bus. W

Sys.)

Labour Code

Valve, common rail remove
2373-01-09-01

(0.6 hrs)
ECM and ACM, Reprogramming
2841-22-02-01

(0.4 hrs)
Accessory Kit, programming
1700-22-03-06

(0.1 hrs)
Valve Cover, Replacement
2115-03-02-02

Use Impact for Time

(0.9 - 1.9 hr.)

If Applicable
Pressure Sensor, Common Rail, Replacement, Valve Cover

Removed
2373-03-03-06

(0.2 hrs)
Wiring Harness, Injector, Replacement (Rear), Valve Cover

removed
2861-03-03-03

Use Impact for Time

(0.3 – 0.4 hrs)
Causal Part
22720232
Mack Trucks North America reserves the right to make any changes in design or to make

additions to or upon its products without incurring any obligations to install the same on

vehicles previously built.
Page

10(10)

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