Cressi-sub MC9 Manual

Regulators repair and maintenance
1
MC9 1st stage
MC9 INT HZ 820097
MC9 DIN 300 bar HZ 820098
January 2009 Rev. MC9/B Ed.C/13

Regulators repair and maintenance
2
MC9 1st stage
WARNING !
January 2009 Rev. MC9/B Ed.C/13
•This manual is intended for use by expert technicians who have already received
training in equipment repairs and maintenance from Cressi-sub.
•This manual is intended for use by expert technicians who have already received
training in equipment repairs and maintenance from Cressi-sub.
•Avoid performing maintenance and/or repair operations on the equipment without
the proper training required to conduct these operations.
•Users must never perform maintenance themselves; all maintenance must be
performed EXCLUSIVELY by an authorized Cressi-Sub center.
•If the information provided in this document is unclear or not fully intelligible,
please contact Cressi-sub before proceeding with any disassembly or maintenance
procedures.
•Before proceeding, Cressi-sub recommends that you read the following document
carefully to familiarize yourself with all the tools and techniques needed to
perform proper equipment maintenance and/or repair.
•Use this document as a guide during the various steps of maintaining and/or
repairing the equipment.

Regulators repair and maintenance
3
MC9 1st stage
WARNING !
January 2009 Rev. MC9/B Ed.C/13
•All operations must be done strictly in the order provided in this document. Failure
to do so could cause the equipment to function poorly, or worse, result in an
accident.
•To prevent any assembly errors when performing maintenance and/or repairs, we
recommend using all the replacement parts provided by Cressi-Sub in every
operation.
•Pay special attention to the recommendations provided in the margin of the figures
that show the various sequences of equipment maintenance and/or repair in order
to avoid any problems that could result in an accident.
•The document below in no way replaces the equipment's instruction manual.
•The procedures described in this document are pertinent to and intended only for
the disassembly, maintenance, and assembly of equipment meant for use with air
(21% oxygen, 79% nitrogen).
•The instructions provided in this document are based on information referring to the
most update equipment available. Cressi Sub reserves the right to make changes at
any time.

Regulators repair and maintenance
5
MC9 DIN 1st stage
•Kit MC9-MC9 S.C.-MC5 Annual replacement kit
•Cod. N° HZ 800047
•Use only Cressi-sub spare parts
•Note: it is recommended to carry out a complete servicing of the regulator yearly or
more frequently in case of intensive use.
(Real Size)
Go back to
January 2009 Rev. MC9/B Ed.C/13

Regulators repair and maintenance
6
MC9 1st stage
•Annual replacement
January 2009 Rev. MC9/B Ed.C/13
•Cressi-Sub recommends complete regulator maintenance at least once a year,
or more frequently in the case of particularly intense use.
•Maintenance must include replacement of all components provided in the
annual equipment maintenance kit.
•The special tools for maintenance of this equipment are illustrated in a section
of this document on page 8.
•Metal parts must be washed with hot water and neutral detergent and rinsed
in fresh water. Any concretions must be removed using ultrasound cleaning or
with diluted acid solutions, always followed by long and thorough rinsing
under running water.
•Do not use acids or solvents on rubber components.
•The new ORs must be greased with a thin layer of silicon grease: this
procedure reduces to a minimum the risk of damage during assembly.
•The metal threading can be lubricated with grease on the first two rings of
threading.

Regulators repair and maintenance
7
•The procedures described in this document are pertinent to and
intended only for the disassembly, maintenance, and assembly of
equipment meant for use with air (21% oxygen, 79% nitrogen).
•Users must never perform maintenance themselves; all
maintenance must be performed EXCLUSIVELY by an authorized
Cressi-Sub center.
•You can find your authorized Cressi-Sub center by asking your
dealer, or Cressi Sub S.p.A. itself by sending an e-mail to:
MC9 1st stage
•Annual replacement
•Use only original Cressi-sub replacement parts
January 2009 Rev. MC9/B Ed.C/13

Regulators repair and maintenance
8
1°stage MC9
Special tools
January 2009 Rev. MC9/B Ed.C/13

Regulators repair and maintenance
9
MC9 S.C. 1st stage:
disassembling procedures
•Remove and replace all O-rings;
•Use a plastic tool or a round pointed metal one in order not to
damage the O-ring seat;
•To replace the O-ring correctly, press its sides to create a bulge
inside which to insert the round pointed tool, as shown in the
pictures;
•Attention: USE ONLY ORIGINAL CRESSI-SUB SPARE PARTS
January 2009 Rev. MC9/B Ed.C/13

Regulators repair and maintenance
10
MC9 1st stage:
disassembling phases
•In case the regulator
has been used under
water for a long time
and shows oxidation
traces, it may be useful
to tap gently with a
plastic hammer all
along the perimeter of
the area to be
removed.
January 2009 Rev. MC9/B Ed.C/13

Regulators repair and maintenance
11
MC9 1st stage: INT
disassembling phases
January 2009 Rev. MC9/B Ed.C/13

Regulators repair and maintenance
12
MC9 1st stage: INT
disassembling phases
•Remove the bracket
nut using the special
spanner, as shown in
the picture.
•After inserting the
threaded tool in one of
the first stage ports,
tighten the regulator in
a vice.
January 2009 Rev. MC9/B Ed.C/13

Riparazione e Manutenzione Erogatori
13
MC9 1st stage: INT
disassembling phases
•In case the
special spanner
is not available,
the bracket nut
can be removed
using a large
adjustable
spanner as
shown in the
picture.
HZ 709018
January 2009 Rev. MC9/B Ed.C/13

Regulators repair and maintenance
15
MC9 1st stage: DIN
disassembling phases
25 K (Kit OR DIN)
HZ 800066
January 2009 Rev. MC9/B Ed.C/13

Regulators repair and maintenance
16
MC9 1st stage: DIN
disassembling phases
•Using the threaded
bar, tighten the 1st
stage in a vice.
•Unscrew the DIN
connector from the
relating thread on the
DIN filter, using a 6
mm. allen wrench.
January 2009 Rev. MC9/B Ed.C/13

Regulators repair and maintenance
17
MC9 1st stage: DIN
disassembling phases
•Warning: in case
the disassembling
operations are
difficult, do not carry
out them with any
wrench extensions,
since this might
damage details of
the equipment!
•In such case please
contact Cressi-sub at
once, before
carrying out any
disassembling
operation.
January 2009 Rev. MC9/B Ed.C/13

Regulators repair and maintenance
18
MC9 1st stage: DIN
disassembling phases
•Remove the DIN
connector ring
from the DIN filter
body.
January 2009 Rev. MC9/B Ed.C/13
31 = HZ 800046

Regulators repair and maintenance
19
MC9 1st stage: DIN
disassembling phases
Continues on page 20
•Unscrew the DIN filter
body using a 24 mm.
hexagonal spanner, as
shown in the picture.
•Pay particular attention:
unscrewing the thread
causes the inner valve
spring to lessen its
resistance, which might
make the inner valve
dart out of its seat.
30 = HZ 800049
January 2009 Rev. MC9/B Ed.C/13

Regulators repair and maintenance
20
MC9 1st stage:
disassembling phases
•Remove the sintered filter and take out the first stage valve
completely.
10K = HZ 800058
6 = HZ 800056
January 2009 Rev. MC9/B Ed.C/13
Table of contents
Other Cressi-sub Diving Instrument manuals