Special Bulletin

SB-10045699-3389

SP12-23

Date

Expiration

Release

Page

08.2012

08.2014

1

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VOLVO D13 ENGINE – EGR VALVE STUCK ISSUE
Prevost vehicles
DESCRIPTION
On the vehicles affected by this bulletin, application of a corrective measure concerning the EGR valve is
necessary due to presence of unnecessary O-rings that may prevent free valve actuation.
2 POSSIBLE OPTIONS
PART 1)

Replacement of the existing EGR valve (requires removal of the cooling pack)

PART 2)

DYNO test

The EGR valve can be replaced with the latest version, not equipped with O-rings. A second corrective
measure consisting in having the engine running at high power rating on a dynamometer (DYNO test) for
a definite period of time. Doing this will burn off the faulty O-rings and get rid of them in an effective way.

MODEL YEAR(S) AND VEHICLES INVOLVED

NOTICE TO SERVICE CENTERS
Verify vehicle eligibility by checking warranty bulletin status with SAP or Vehicle Warranty
Information tool found on Prevost–Systems tab of the Volvo Trucks Dealer Portal

Model

VIN

H3-41, H3-45 coaches
and

From 2PCH33497DC712119 up to 2PCH33499DC712199 incl.

H3-45 VIP motorhomes
Model Year : 2012 - 2013
X3-45 coaches
XLII shells

From 2PCYS3497CC735286 up to 2PCG33491DC735326 incl.

X3-45 VIP motorhomes
Model Year : 2012 - 2013
This bulletin does not necessarily apply to all the above-mentioned vehicles, some vehicles may have been modified
before delivery. The owners of the vehicles affected by this bulletin will be advised by a letter indicating the Vehicle
Identification Number (VIN) of each vehicle concerned.

Special Bulletin SP - [Diffusé] No. Révision: 4 - Date de diffusion: 2011-06-22 15:28:22

Special Bulletin

SP12-23
Date

Expiration

Release

Page

08.2012

08.2014

1

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BEFORE UNDERTAKING ANY CORRECTIVE MEASURES, YOU MUST CHECK FIRST THAT THE PRESENT EGR VALVE IS
REALLY INVOLVED. CHECK THE PART NUMBER AND DATE CODE ON THE EGR VALVE BODY (refer to the table of involved
EGR valve below).

VOLVO PART NUMBER

1
2
3
4

21735861
21735862
21735863
21735864

DATE CODE OF AFFECTED
EGR VALVE

from 086M to162M incl.

Special Bulletin SP - [Diffusé] No. Révision: 4 - Date de diffusion: 2011-06-22 15:28:22

Special Bulletin

PART 1

SP12-23
Date

Expiration

Release

Page

08.2012

08.2014

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REPLACEMENT OF THE EGR VALVE

MATERIAL
Order the following parts:
Part No.

Description

Qty

21735863

EGR VALVE

1

20755169

V-BAND CLAMP, EGR HOT PIPE

2

20841816

GASKET, HOT PIPE

2

20850815

GASKET, EGR VALVE TWIN PORTS

1

O-RING, OIL LINES

2

FLANGE SCREW, M10X90

4

976014
21528673

NOTE

Material can be obtained through regular channels.

DANGER
Park vehicle safely, apply parking brake, stop engine. In the battery box, set the battery cut-off switch
to the OFF position prior to working on the vehicle.
1)

To easy removal and replacement of the EGR valve, you must proceed to the standard removal
procedure of the cooling pack (charge air cooler, radiator, radiator fan clutch and angle drive
assembly). Remove the cooling pack and proceed to the EGR valve replacement as described in
EGR VALVE, REPLACEMENT procedure found on IMPACT (see images below).
RESULTS

Special Bulletin SP - [Diffusé] No. Révision: 4 - Date de diffusion: 2011-06-22 15:28:22

Special Bulletin

SP12-23
Date

Expiration

Release

Page

08.2012

08.2014

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NOTE

TIGHTENING TORQUES
EGR VALVE MOUNTING FLANGE SCREW
Tighten the flange screws diagonally
Step 1. Tighten 15±3 lbf-ft (20±4 Nm)
Step 2. Tighten 45±4 lbf-ft (61±3 Nm)
EGR HOT PIPE V-BAND CLAMPS
Tighten to 50 lbf-in (6 Nm)

Special Bulletin SP - [Diffusé] No. Révision: 4 - Date de diffusion: 2011-06-22 15:28:22

Special Bulletin

PART 2

SP12-23
Date

Expiration

Release

Page

08.2012

08.2014

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DYNO TEST

Here is the procedure to get rid (burn) of the EGR valve O-rings through a chassis DYNO test.
GENERAL TEST GOAL
We need T1 (EngExhTemp) to reach about 430°C (806°F) which should correspond to about 550°C
(1022°F) exhaust manifold temperature.
This 550C is our real target, but we have no temperature sensor there.
We need to have that temperature for a minimum of 18 minutes.
 T1 = Exhaust temperature at DPF Inlet = approximately exhaust temperature at engine outlet =
EngExhTemp (in Volvo engineering tools). This is not DPF Temp!
 T1 + 120°C (248°F) = approximately exhaust manifold temperature = approximately exhaust
temperature at EGR valve (just for your information).
CHASSIS DYNO TECHNICAL REQUIREMENTS and PREPARATION



Select a heavy duty chassis DYNO that can handle HD Trucks wheel HP, high wheel torque (high
HP at low RPM), and vehicle drive axle weight.
Minimum 300Hp at drive axle wheels. For more information please refer to technical details table
at the end of this procedure.

VEHICLE PREPARATION






Check engine oil level.
Closely monitor coolant level, and note it. We may need this information later on.
Remove ABS fuse #23 (located in front electrical compartment).
Reason: rear wheels turning + front wheel not turning = Incoherence = ESP engaged.
ABS fuse removal avoids this behavior.
IMPORTANT: to prevent activation of the AFSS (automatic fire suppression system), unplug
connector L282A at the extinguisher cartridge.
HVAC running at full capacity if needed (see note 3 below).

TEST PROCEDURE – Without Premium Tech Tool (BLIND TEST)






th
With Allison : Transmission should be set in 5 gear (see note 1 below).
Adjust engine + DYNO parameters for engine to be running at FULL LOAD, at 1200 ~ 1250 RPM.
Make sure conditions are as stable as possible.
Once a stable condition is reached, have a full load warm up of 2 minutes (see note 2 below).
Run 18 minutes at full load ~1200 RPM (see note 2 below).
Total = 20 minutes at FULL LOAD ~1200 RPM (see note 2 below).

Note 1:
Transmission should be set in 5th gear. (At lower gears, high torque could break the
DYNO.)
Unfortunately fluctuations may occur, mainly at lower engine RPMs.
At low RPM + high loads, the transmission has the tendency to down shift in 4th.
If you use the DYNO of an Allison Transmission Dealer, the best thing would be to ask
them to use the Allison DOC Interface tool, and perform a clutch test to really LOCK the
transmission in 5th gear.
Special Bulletin SP - [Diffusé] No. Révision: 4 - Date de diffusion: 2011-06-22 15:28:22

Special Bulletin

SP12-23
Date

Expiration

Release

Page

08.2012

08.2014

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This is what has been done during the first DYNO test performed in Quebec city.
Note 2:
Unfortunately fluctuations will occur, because of our large cooling fan being engaged &
disengaged, or previous gear down shifts in 4th.
 Engine should remain at full load, in the 1200 ~ 1250 RPM target range.
 Dynamometer parameters should be continuously adjusted to compensate.
You can either adjust DYNO load, or vehicle wheel speed.
For example, with an axle ratio of 3.58, we were constantly adjusting
target speed between 55 and 58 MPH. And it did work well.
 1250-1300 RPM can be reached for short periods. Not ideal, but no limitation.
 1300-1400 RPM can be reached for short periods of time (1400 RPM can be reached, but if it happens, please extend test time to
compensate for ¨2x time lost¨.
Note 3:
Check technical details table at the end of this procedure, you will notice that, in the range
of 1200-1250 RPM, vehicle wheel HP can reach 340HP.
 In case DYNO HP is around 300HP at the wheel, it will be limit (this was our
case!).
 In order to help, we were making the HVAC running at full capacity.

TEST PROCEDURE – With Premium Tech Tool (and monitoring T1)
Exact same activities as previous procedure.
th
 With Allison : Transmission should be set in 5 gear (see note 1).
 Adjust engine + DYNO parameters for engine to be running at FULL LOAD, at 1200 ~ 1250 RPM.
Make sure conditions are as stable as possible.
 Once a stable condition is reached, have a full load warm up of 2 minutes (see note 2).
 Run 18 minutes at full load ~1200 RPM (see note 2).
 Total = 20 minutes at FULL LOAD ~1200 RPM (see note 2).
But monitoring engine exhaust temperature (T1) will allow you to be more confident on the
exhaust temperatures and high temperature condition cumulated time achieved.
No uncertainty like, should I run a little longer?
o
o Target Engine exhaust temperature : T1 >= 430 C (806°F)
o If you reach or exceed this temperature for a minimum of 18 minutes, you’re all set!
o No need for >1300 RPM monitoring. No time compensation for >1300RPM.
FYI, on H3 we reached a steady 425°C-460oC (797°F-860°F), and on XL we reached a steady
450°C-485oC (842°F-905°F).

POST TEST PROCEDURE
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