Page 1
TECHNICAL MAINTENANCE MANUAL TECHNICALLY INSPIRED XL4 SECOND STAGE...
Page 2
CHANGE RECORD PAGE # REV. DATE TITLE OR DESCRIPTION CHANGE MADE BY 15/20 03/22/19 Aqua Lung America Service Kit Part Number Change to RS135111 03/22/19 Aqua Lung America AT75 Tool Part Number Change to RA911116 11/2020 All New Part Numbers Aqua Lung America...
This manual provides factory prescribed procedures for the correct service and other units. Delicate parts, which contain critical sealing surfaces, must repair of the Aqua Lung or Apeks products described in this manual. It is not be protected and isolated from other parts to prevent damage during the intended to be used as an instructional manual for untrained personnel.
XL4 SECOND STAGE TECHNICAL MAINTENANCE MANUAL DISASSEMBLY PROCEDURE Unfasten the mouthpiece clip (8) and pull the mouthpiece off the case (7). CAUTION: Use only a plastic or brass o-ring removal tool when removing o-rings to prevent damage to the sealing sur- face.
Page 6
Position the venturi lever (24) vertically. Using the venturi lever Insert a 5mm hex key into removal tool (RG911232), the reg hose threaded align the cutout in the tool so it end of the inlet fitting (10) and will engage the tab of the venturi turn the seat (14) CLOCKWISE.
XL4 SECOND STAGE TECHNICAL MAINTENANCE MANUAL INSPECTION PROCEDURE Using your fingernail, remove the MP seat (17) from the shuttle valve (18). NOTE: Before performing any reassembly procedures, there are several parts that must be inspected. The following section details the parts and areas that must be checked.
REASSEMBLY PROCEDURE Position the large fin of the spindle body (16) down. Press the end of the shuttle valve NOTE: Before performing any reassembly, it is important to inspect all parts, both new and those that are being reused, to ensure that (18) to fully compress the spring every part and component is perfectly clean and free of any dust, (20), until it passes the triangular...
Page 9
XL4 SECOND STAGE TECHNICAL MAINTENANCE MANUAL Slide the inlet shroud (12) hex side first onto the inlet fitting Carefully insert the spindle body assembly into the case (6). Insert (10) past the already installed o-ring. the tool into the venturi side of the case, carefully rotate the tool until the cutout in the tool engages with the spindle body assembly.
Place the inner locking Confirm the male end of the Align tool to ring (4) with the flat side MP hose is connected to locking ring facing up onto the diaphragm a properly adjusted first stage (6). Use the diaphragm clamp regulator.
Page 11
XL4 SECOND STAGE TECHNICAL MAINTENANCE MANUAL Keeping the lever setting tool in place, press inward on the ad- Turn off the air supply and purge the second stage by pressing justment wheel of the inline tool. Slowly rotate the adjustment the center pad of the diaphragm (6).
FINAL ASSEMBLY SECOND STAGE OPENING EFFORT TEST Insert the micro adjuster tool (RG911227) into the open side Place the purge button (2) of the case (7), making sure that the hexagonal bit engages inside the clamp ring (1) into the micro adjuster screw (23). ensuring the three locating tabs line up.
XL4 SECOND STAGE TECHNICAL MAINTENANCE MANUAL FINAL TESTING If equipped with a Comfo- bite mouthpiece, make sure the ‘bridge’ of the mouthpiece (9) is facing upward. Stretch EXTERNAL LEAK TEST the mouthpiece over the outlet port. Wrap the mouthpiece clip...
Page 14
TABLE 1: TROUBLESHOOTING GUIDE SYMPTOM POSSIBLE CAUSE TREATMENT 1. Extremely high MP from first stage 1. Refer to First Stage Troubleshooting Guide 2. The MP seat (17) is damaged 2. Replace the MP seat 3. The seat (14) was adjusted incorrectly 3.
Page 15
XL4 SECOND STAGE TECHNICAL MAINTENANCE MANUAL TABLE 2: LIST OF TOOLS PART # DESCRIPTION APPLICATION RG911161 Diaphragm Clamp Tool Removal/installation of inner locking ring (4) Brass O-ring RA911143 Tool Kit Removal and replacement of o-rings Plastic O-ring RA911141 Tool RA911116...
When it comes to issues of nitrox safety and compatibility, the concerns lie primarily with the regulator’s first stage as it is subjected to high inlet pressures. High inlet pressures lead to adiabatic compression or heating of the gas. The Aqua Lung or Apeks regulator product described in this manual, when properly cleaned and assembled, is authorized for use with enriched air nitrox (EAN) that does not ex- ceed 40% (EAN 40).
Page 21
AUTHORIZED TECHNICIAN TECHNICAL MAINTENANCE MANUAL XL4 SECOND STAGE TECHNICALLY INSPIRED Aqua Lung USA 2340 Cousteau Court, Vista CA 92081 760-597-5000 www.aqualung.com Rev 11-2020...
Need help?
Do you have a question about the XL4 SECOND STAGE and is the answer not in the manual?
Questions and answers