Uwatec MK 25 Assembly instructions

SCUBAPRO MK 25/MK 20 First Stages
2003 SCUBAPRO
Important note: The following information is not designed to be a complete training guide for servicing the listed SCUBAPRO regulators. All SCUBAPRO
technicians are required to attend an annual service training program to insure safe handling and servicing of SCUBAPRO products. All SCUBAPRO technicians
must be employed by an authorized SCUBAPRO facility.
1
SCUBAPRO
Repair Guide
MK 25/MK 20
First Stages
USE THIS GUIDE AS A REFERENCE WHEN SERVICING
THE MK 25 AND MK 20 FIRST STAGES

SCUBAPRO MK 25/MK 20 First Stages
2003 SCUBAPRO
Important note: The following information is not designed to be a complete training guide for servicing the listed SCUBAPRO regulators. All SCUBAPRO
technicians are required to attend an annual service training program to insure safe handling and servicing of SCUBAPRO products. All SCUBAPRO technicians
must be employed by an authorized SCUBAPRO facility.
2
TOOLS NEEDED FOR REPAIR OF MK 25-MK 20
P/N43040000
TOOLS
NEEDED
Quantity Part Number Description
1 Ratchet
1 20-155-500
(Peter Built)
1” Yoke Nut Socket
1 20.150-200
(Peter Built)
MK 25/MK 20 Assembly Tool
1 set 10.102.100
(Peter Built)
Brass o’ring picks
1 tube 41.047.000 Christo-Lube Christo-Lube
OXYGEN COMPATIBLE LUBRICANT
P/N 41-047-000
1 47.010.000 Counter Mat
1 41.496.101 Lubricant syringe Monoject
1 43.040.000 Universal Tool
1 20-115-100
(Peter Built)
First Stage Handle
1 Torque Wrench
1 Hex Key Set
1 Crescent wrench
1 20.500.200
(Peter Built)
Pneumatic Adjusting tool
1 18.300.500
(Peter Built)
Blow Gun/Air Nozzle
ICON LEGEND
Inspect carefully, replace if needed
Monoject Lubricate properly
Replace annually
Dynamic o’ring, lubricate properly
P/N43040000
TOOLS
NEEDED
No tools needed for this step
Indicates the regulators affected by this step

SCUBAPRO MK 25/MK 20 First Stages
2003 SCUBAPRO
Important note: The following information is not designed to be a complete training guide for servicing the listed SCUBAPRO regulators. All SCUBAPRO
technicians are required to attend an annual service training program to insure safe handling and servicing of SCUBAPRO products. All SCUBAPRO technicians
must be employed by an authorized SCUBAPRO facility.
3
Remove all hoses.
Thread the first stage handle into the
high-pressure port as shown.
Use the ratchet and yoke nut socket to
remove the yoke nut from the first
stage.
Remove the yoke cover if cleaning the
yoke is indicated.
5/32”
For DIN Regulators
Remove all hoses.
Thread the first stage handle into the
high-pressure port as shown.
Loosen the filter retainer using a 5/32”
hex wrench.

SCUBAPRO MK 25/MK 20 First Stages
2003 SCUBAPRO
Important note: The following information is not designed to be a complete training guide for servicing the listed SCUBAPRO regulators. All SCUBAPRO
technicians are required to attend an annual service training program to insure safe handling and servicing of SCUBAPRO products. All SCUBAPRO technicians
must be employed by an authorized SCUBAPRO facility.
4
Remove the yoke nut and cap from the
first stage.
Loosen the star clip and remove the
filter.
Remove the yoke nut o’ring.
6mm
For DIN Regulators
Remove the filter retainer, spring, filter,
DIN adapter and o’ring.
Loosen the DIN fitting using a 6mm hex
wrench.
Remove the end cap.
Loosen the seat retainer using a
properly sized wrench while holding the
first stage with a first stage handle.

SCUBAPRO MK 25/MK 20 First Stages
2003 SCUBAPRO
Important note: The following information is not designed to be a complete training guide for servicing the listed SCUBAPRO regulators. All SCUBAPRO
technicians are required to attend an annual service training program to insure safe handling and servicing of SCUBAPRO products. All SCUBAPRO technicians
must be employed by an authorized SCUBAPRO facility.
5
3/8”
On some early models of the MK 20
this was loosened using a 3/8” hex
wrench.
Loosen the seat retainer while holding
the first stage with a first stage handle.
5/32”
Remove the seat retainer. The high-
pressure seat assembly and spring can
now be removed.
On the current version of the MK 25 the
seat retainer is adjustable.
Disassemble for cleaning using a 5/32”
hex wrench.
NOTE: The adjusting screw is turned
clockwise to remove.
Use the universal tool to loosen the cap
from the body. Hold the regulator body
with a first stage handle.

SCUBAPRO MK 25/MK 20 First Stages
2003 SCUBAPRO
Important note: The following information is not designed to be a complete training guide for servicing the listed SCUBAPRO regulators. All SCUBAPRO
technicians are required to attend an annual service training program to insure safe handling and servicing of SCUBAPRO products. All SCUBAPRO technicians
must be employed by an authorized SCUBAPRO facility.
6
P/N43040000
TOOLS
NEEDED
No tools needed
this step
Separate the cap from the regulator
body. Carefully remove the piston
assembly and spring.
Use the brass pick (blunt end) to
carefully push the piston stem o’ring
assembly from the regulator body.
7/32”
5/32”
Use a 7/32” hex wrench to remove the
swivel retainer from the regulator cap.
Use a 5/32” hex wrench to remove the
low-pressure plugs.

SCUBAPRO MK 25/MK 20 First Stages
2003 SCUBAPRO
Important note: The following information is not designed to be a complete training guide for servicing the listed SCUBAPRO regulators. All SCUBAPRO
technicians are required to attend an annual service training program to insure safe handling and servicing of SCUBAPRO products. All SCUBAPRO technicians
must be employed by an authorized SCUBAPRO facility.
7
Monoject
7/32”
Following cleaning, inspect and
lubricate o’rings and washer as shown.
Reassemble the swivel retainer to the
regulator cap using a 7/32” hex and
torque wrench. Apply 70 in-lbs/8 N-m.
Monoject
Insert the stem o’ring assembly using
the stem o’ring insertion tool. The
o’ring should be lubricated to dynamic
specifications.
Note that the washer with the ledge
should be placed as shown during
reassembly.
Push the assembly into the regulator
body.

SCUBAPRO MK 25/MK 20 First Stages
2003 SCUBAPRO
Important note: The following information is not designed to be a complete training guide for servicing the listed SCUBAPRO regulators. All SCUBAPRO
technicians are required to attend an annual service training program to insure safe handling and servicing of SCUBAPRO products. All SCUBAPRO technicians
must be employed by an authorized SCUBAPRO facility.
8
Remove the insertion tool by twisting
slightly and then pulling out, then
reverse the tool and re-insert it into the
regulator body.
Reassemble the piston assembly.
Replace and lubricate the piston
o’rings.
Hold the o’ring insertion tool in place to
insure that the piston knife-edge is not
damaged during assembly.
Thread the cap and swivel assembly
on the regulator body. Hold the o’ring
insertion tool in place to insure that the
piston knife-edge is not damaged
during assembly.
Tighten the regulator body to the cap
and swivel assembly using the first
stage handle and the universal tool as
shown.

SCUBAPRO MK 25/MK 20 First Stages
2003 SCUBAPRO
Important note: The following information is not designed to be a complete training guide for servicing the listed SCUBAPRO regulators. All SCUBAPRO
technicians are required to attend an annual service training program to insure safe handling and servicing of SCUBAPRO products. All SCUBAPRO technicians
must be employed by an authorized SCUBAPRO facility.
9
Monoject
5/32”
Replace the high-pressure seat and
replace/lubricate the high-pressure
o’ring. With the spring and the spacer,
Insert in the regulator body.
In the MK 25 the adjusting screw
should be re-inserted into the high-
pressure seat retainer using a 5/32”
hex wrench.
NOTE: To tighten the adjustment
screw, turn counter-clockwise.
Tighten the high-pressure seat retainer.
Use a torque wrench to tighten to 130
in-lbs/15 N-m.
3/8”
On some early models of the MK 20
the seat retainer is tightened using a
3/8” hex wrench.
Tighten the high-pressure seat retainer.
Use a torque wrench to tighten to 130
in-lbs/15 N-m.

SCUBAPRO MK 25/MK 20 First Stages
2003 SCUBAPRO
Important note: The following information is not designed to be a complete training guide for servicing the listed SCUBAPRO regulators. All SCUBAPRO
technicians are required to attend an annual service training program to insure safe handling and servicing of SCUBAPRO products. All SCUBAPRO technicians
must be employed by an authorized SCUBAPRO facility.
10
Monoject
Replace the filter and star retainer.
Lubricate the yoke nut o’ring.
Insert the filter, o’ring, and star retainer
into the yoke nut. Assemble with the
yoke saddle.
Monoject
For DIN Regulators
Lubricate the DIN fitting-to-body o’ring.
Assemble the o’ring and DIN fitting to
the regulator body.
Reassemble and tighten the yoke nut
to the regulator body. Torque to 266
in-lbs/30 N-m.
Place the yoke cover on the yoke.

SCUBAPRO MK 25/MK 20 First Stages
2003 SCUBAPRO
Important note: The following information is not designed to be a complete training guide for servicing the listed SCUBAPRO regulators. All SCUBAPRO
technicians are required to attend an annual service training program to insure safe handling and servicing of SCUBAPRO products. All SCUBAPRO technicians
must be employed by an authorized SCUBAPRO facility.
11
6mm
For DIN Regulators
Tighten the DIN fitting using a 6mm
hex. Torque to 266 in-lbs/30 N-m.
Hold the first stage using the first stage
handle.
For DIN Regulators
Replace the filter and assemble the
spring, filter and filter retainer in the
DIN fitting.

SCUBAPRO MK 25/MK 20 First Stages
2003 SCUBAPRO
Important note: The following information is not designed to be a complete training guide for servicing the listed SCUBAPRO regulators. All SCUBAPRO
technicians are required to attend an annual service training program to insure safe handling and servicing of SCUBAPRO products. All SCUBAPRO technicians
must be employed by an authorized SCUBAPRO facility.
12
5/32”
For DIN Regulators
Tighten the filter retainer with a 5/32”
hex. Torque to 35 in-lbs/4 N-m. Hold
the first stage using the first stage
handle.
Check the intermediate pressure using
the pneumatic adjusting tool.
Intermediate pressure range: 125psi to
145psi at 3000psi and 300psi supply
pressure.
5/32”
Intermediate pressure adjustments can
be made using the adjusting screw on
the high-pressure seat retainer. Use a
5/32” hex wrench.
CAUTION: Be certain that supply air is
turned off and regulator is purged prior
to making adjustments.

SCUBAPRO MK 25/MK 20 First Stages
2003 SCUBAPRO
Important note: The following information is not designed to be a complete training guide for servicing the listed SCUBAPRO regulators. All SCUBAPRO
technicians are required to attend an annual service training program to insure safe handling and servicing of SCUBAPRO products. All SCUBAPRO technicians
must be employed by an authorized SCUBAPRO facility.
13
3/8”
Earlier models of MK 20 can be
adjusted by adding/removing shims.
Each can adjust the intermediate
pressure 5 – 10 psi.
P/N43040000
TOOLS
NEEDED
No tools needed
this step
Replace the cap on the regulator body.