SERVICE BULLETIN
SB2507
ADDRESSEES

: Owners and operators
ABC Customer Care and Parts Source

VEHICLE MODEL

: CX35 MY2023, CX45 MY2023/2025

MANUAL SECTION

: 08.14 Climate control – water circuit

BULLETIN TYPE

: Field change program

DATE

: October 1st, 2025

SUBJECT

: To check setting of Burkert valve block pressure
regulator in interior heating circuit

TERMS & CONDITIONS

: Refer to chapter "Warranty" further on in this bulletin.

APPLICATION
This field change program is applicable to below mentioned units:
Vehicle type
CX35 MY2023

VIN
8308083099

No. of vehicles
20

CX45 MY2023
CX45 MY2025

8443284569
8457084642

138
73

DESCRIPTION
VDL Van Hool has received a few complains about the improper operation of the interior
heating system. Investigation has shown that this is caused by an improper setting of the
pressure regulator on the Burkert valve block. The too low setting of the pressure regulator
prevents the water valves from opening when requested by the control system.

Figure 1: In coolant heater
compartment, location of Burkert
pressure regulator

To address this issue, VDL Van Hool is conducting a field change program in which is
requested to check/set the pressure regulator output pressure according to the instructions
in this service bulletin.
Continued on next page.
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SPECIAL TOOLS, EQUIPMENT OR SERVICES



Pressure gauge (0 to 10 bar) (0 to 145 psi)
Fitting adaptor to connect pressure gauge to compressed-air line

JOB REQUIREMENTS
This job has to be carried out by an experienced automotive mechanic.

PREPARATIONS






Park the coach on a level-surfaced service pit.
Apply the parking brake and shut down the engine.
Put a “DO NOT OPERATE” tag on the instrument panel.
Compressed-air system charged to maximum operating pressure.
Read the entire procedure before beginning to work.

WARNING!
Observe safe shop practices at all times.

PROCEDURE
Step
1
2
3
4

Action
Open the engine compartment rear access door.
Make sure the vehicle ignition is off to ensure the compressed-air line which
must be disconnected in step 4 is depressurized.
Open the coolant heater compartment.
Disconnect the compressed-air supply line at the roof water valve (= piloted
by solenoid valve V114) by pressing the release collar of the fitting inwards
while simultaneously pulling the tubing from the fitting.

Water valve of
roof circuit
Air line fitting
Figure 2: Compressed-air line fitting
at water valve of roof circuit

Continued on next page.
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5

Connect the pressure gauge at the disconnected compressed-air line (6 mm
dia.).
Switch on the vehicle ignition.
Use the climate control test program (refer to chapter 8.2 of the maintenance
manual, under "Passenger compartment control system: to troubleshoot
using the dashboard display") to open the roof water valve.
Does the pressure gauge reading indicates a pressure of 4 bar (60 psi).

6
7

8




If yes, go further with step 9.
If not, set the pressure regulator output pressure as described in “STEP 8
IN DETAIL” and then go further with step 9.
Switch off the vehicle ignition to depressurize the compressed-air line.
Disconnect the pressure gauge and reconnect the compressed-air line to the
water valve.
Notify ABC Companies by mail. Write the text “SB2507 executed for VIN…..” in
the mail and send the mail to [email protected].
For ABC Companies only: register through the registration button located
behind service bulletin SB2507 on the VDL Van Hool customer portal. Write
the text "SB2507 executed" in the field "Remark". Labor allowance will only
be awarded after VDL Van Hool has received the registration.

9
10
11
12

End of procedure.

STEP 8 IN DETAIL: To set pressure regulator output pressure
Step
8.1

Action
Remove the plastic protection cap by using the tip of a flat blade screwdriver.
Place the tip of the screwdriver in between the gap and then put a little force
upwards to detach the cap.

Figure 3: Removing the
protection cap of the
pressure regulator

Continued on next page.
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8.2

NOTE: If the output pressure remains unchanged while turning the setting
screw, the plastic cover of the pressure regulator is not tightly fastened and
must be hand-tightened first using the lobe grip knob.
While having a view at the pressure gauge, turn the setting screw by using
for example long needle nose pliers until a output pressure of 4 bar (60 psi)
has been reached. Turn clockwise to increase, counterclockwise to decrease
the output pressure.

Setting screw

Lobe grip knob

8.3

Figure 4

Re-install the protection cap by pressing.

WARRANTY
This warranty does not cover any consequential or incidental damages, including but not
limited to, economic loss, communication expenses, lodging, replacement charges, towing,
loss of time, cargo damage, overtime, or mileage.

1. Terms and conditions:

VDL Van Hool will accept warranty claims for this repair as follows:
Parts: no parts
Labor allowance: 15 minutes of labor will be awarded per vehicle
Campaign/expiration date: Service Bulletin issue date + 3 months
2. Claim references:

Job code: O62507N
Claim submission: Contact ABC Customer Care Warranty Department for guidance.
Monitoring and performance: The claim records pertaining to this Bulletin will be
used to determine that the remedy has been executed in accordance with the
manufacturer’s instructions and to evaluate the status of this Field Change Program.

Continued on next page.
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HELP DESK
If there are any questions, please call ABC Customer Care & Parts Source toll-free for
guidance on 1-877-427-7278. Listen for the prompts for warranty and select that option.
DISCLAIMER
The procedures contained herein are not exclusive. VDL Van Hool cannot possibly know,
evaluate, or advise the transportation industry of all conceivable ways in which a
procedure may be undertaken or of the possible consequences of each such procedure.
Other procedures may be as good, or better, depending upon the particular circumstances
involved. Each carrier who uses the procedures herein must first satisfy itself thoroughly
that neither the safety of its employees or agents, nor the safety or usefulness of any
products, will be jeopardized by any procedure selected.

INFORMATION HANDLING
Important additions and modifications regarding technical information not yet included in
the manual will be communicated through service bulletins.

VDL VAN HOOL CUSTOMER PORTAL
Consult the customer portal regularly for the latest service documentation. In addition to
the maintenance manual, you will also find the operating manual and the spare parts
catalogue of your vehicle on the customer portal. The customer portal is accessible
through www.vdlvanhool.com/MyVDL Van Hool, and only with a code (password) from
VDL Van Hool. If you do not have a password yet, request it by using the link on the VDL
Van Hool website.

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