Tightening Practices for Hydraulic Connections

TASK 20-23-11-917-001-A
Tightening Practices for Hydraulic Connections

WARNING: OBEY THE HYDRAULIC SAFETY PROCEDURES. WORK ON THE HYDRAULIC SYSTEMS CAN BE DANGEROUS.

WARNING: BE CAREFUL WHEN YOU USE CONSUMABLE MATERIALS. OBEY THE MATERIAL MANUFACTURER'S INSTRUCTIONS AND YOUR LOCAL REGULATIONS.

1. Reason for the Job
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
98F29003000000	1	WRENCHES-STANDARD TORQUE SET

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.02ABA1)	Phosphate Ester Hydraulic Fluid-General Power - -
(Material No.03LDA1)	Grease-Hydraulic Systems - -
(Material No.14SBA1)	Textile-Lint free Cotton -

C. Referenced Information

REFERENCE	DESIGNATION
TASK 12-12-29-611-001-A	Fill the Hydraulic Fluid Reservoir with a Hand Pump
TASK 12-12-29-611-002-A	Fill the Hydraulic Fluid Reservoir with a Hydraulic Service Cart
TASK 20-21-12-911-001-A	Tightening Torques for Pipe Unions (not for OXYGEN Unions)
TASK 20-23-22-910-001-A	Marking of the Unions after Application of Standard or Specific Tightening Torque
TASK 20-29-00-911-002-A	Removal/Installation of an O-ring (Hydraulic Systems)
TASK 29-00-00-870-001-A	Bleeding Procedure of the Green Hydraulic System Upstream of the Engine Pump
TASK 29-00-00-870-002-A	Bleeding Procedure of the Green Hydraulic System Upstream of the PTU
TASK 29-00-00-870-003-A	Bleeding Procedure of the Green Hydraulic System Downstream of the Engine Pump
TASK 29-00-00-870-004-A	Bleeding Procedure of the Yellow Hydraulic System Upstream of the Engine Pump
TASK 29-00-00-870-005-A	Bleeding Procedure of the Yellow Hydraulic System Upstream of the PTU
TASK 29-00-00-870-006-A	Bleeding Procedure of the Yellow Hydraulic System Upstream of the Yellow E-Pump
TASK 29-00-00-870-007-A	Bleeding Procedure of the Yellow Hydraulic System Downstream of the Engine Pump
TASK 29-00-00-870-008-A	Bleeding Procedure of the Blue Hydraulic System Upstream of the Blue E-Pump
TASK 29-00-00-870-009-A	Bleeding Procedure of the Blue Hydraulic System Downstream of the Blue E-Pump
TASK 29-10-00-863-001-A	Pressurize the Green Hydraulic System with a Hydraulic Ground Power-Cart
TASK 29-10-00-863-002-A	Pressurize the Yellow Hydraulic System with a Hydraulic Ground Power-Cart
TASK 29-10-00-863-003-A	Pressurize the Blue Hydraulic System with a Hydraulic Ground Power-Cart
TASK 29-10-00-863-003-A-01	Pressurize the Blue Hydraulic System with the Blue Electric Pump
TASK 29-14-00-614-002-A	Pressurization of the Hydraulic Reservoirs through the Ground Connector
TASK 29-14-00-614-002-A-01	Pressurization of the Hydraulic Reservoirs with the Auxiliary Power Unit (APU)
TASK 29-23-00-863-001-A	Pressurize the Green Hydraulic System from the Yellow Hydraulic System through the PTU with the Electric Pump
TASK 29-23-00-863-002-A	Pressurize the Yellow Hydraulic System from the Green Hydraulic System through the PTU with the Ground Service Cart
TASK 32-42-00-870-001-A	Bleeding of the Normal Braking at the Brake Units
TASK 32-43-00-612-001-A	Filling and Bleeding of the Low Pressure Control System of the Alternate Braking
TASK 32-43-00-612-001-A-01	Filling and Bleeding of the Low Pressure Control System of the Alternate Braking using Green Reservoir fluid
TASK 32-43-00-870-002-A	Bleeding of the High Pressure Alternate Braking System
Lubrication of the Connections
Adjustment of the Torque Value
Typical Examples of Connections

3. Job Set-up
Subtask 20-23-11-210-058-A

A. Visual Inspection Before Assembly
(1) Make sure that the parts you assemble are clean and free of contamination.
(2) Make sure that the parts you assemble are not damaged. Specially, examine the sealing surfaces (on fittings and pipe ends) and the threads of the fittings.

NOTE: Reject any part that shows signs of damage (scratches, nicks, deformation...).

4. Procedure
Subtask 20-23-11-917-082-A

CAUTION: ONLY USE THE SPECIFIED LUBRICANT TO LUBRICATE THE FITTING THREADS AND THE SHOULDER OF THE SLEEVE.

CAUTION: ONLY USE HYDRAULIC FLUID MATERIAL NO. 02ABA1 TO LUBRICATE THE THREAD OF THE HOUSING. OTHER LUBRICANTS CAN CAUSE DAMAGE TO THE O-RING.

A. Lubrication

Lubrication of the Connections

(1) For the pipe connection (union, nut and sleeve):

Lubricate with Phosphate Ester Hydraulic Fluid-General Power - - (Material No.02ABA1) or Grease-Hydraulic Systems - - (Material No.03LDA1) on the areas as follows:

The thread of the union
The rear of the sleeve collar.

NOTE: It is not permitted to apply lubricant on the thread of the nut and on the contact surfaces between the sleeve and the union.

(2) For the plug in component (housing side only):

Lubricate only the thread of the housing with Phosphate Ester Hydraulic Fluid-General Power - - (Material No.02ABA1) .
Do not lubricate the external thread of the plug-in component (O-ring side) because the lubricant can push out the O-ring from the plug-in component during the assembly.
Apply lubrication principle for the related coupling type on the opposite side connection of the housing.
(3) For the external-swaged pipe couplings with the swivel nut or the hose end fittings with the nut:

Lubricate with Phosphate Ester Hydraulic Fluid-General Power - - (Material No.02ABA1) or Grease-Hydraulic Systems - - (Material No.03LDA1) on the areas as follows:

The thread of the union only
The wire from the back of the nut. Then turn the nut to make sure that the complete wire is correctly lubricated.

NOTE: It is not permitted to apply lubricant on the thread of the nut and on the contact surfaces between the sleeve and the union.

(4) Remove the unwanted lubricant with a clean, dry Textile-Lint free Cotton - (Material No.14SBA1) .

Subtask 20-23-11-917-083-A

B. Assembly

NOTE: Connection on straight plug-in components or bulkhead fittings:

Straight plug-in components.
You must install and torque the straight plug-in component to the applicable torque value before you connect the pipe (Ref. AMM TASK 20-29-00-911-002).
Straight bulkhead fittings.
You must install the straight bulkhead fittings and torque the locknut to the applicable value before you connect the pipe.
Swivel bulkhead fittings.
You must connect and torque the pipe sleeve nuts (at each end of the fitting) to the applicable value before you torque the locknut of the swivel bulkhead fitting to the applicable value.

(1) Put the pipe in position and make sure that:

the pipe you install is not too short or too long
the pipe you install can be put in position without too much force on the clamp blocks
the pipe is correctly aligned at unions.

NOTE: The force necessary to correctly align the pipe must not be more than light finger pressure ( 1 daN (2.2481 lbf)).

(2) Align the pipe and the fitting and engage tube end. The sleeve must fully touch the mating surface of the fitting.
(3) Tighten the sleeve nut with your hand until it touches sleeve shoulder.

NOTE: The nut must turn freely on the thread. This shows that the tube ends are correctly aligned.

NOTE: You must connect and tighten with your hand all the ends of the pipe before you apply the tightening torque on one end.

NOTE: When you install a pipe on a tee or a cross, you must connect and tighten with your hand all the connections of the tee or the cross before you apply the tightening torque on one end.

NOTE: When you connect a flexible hose, make sure that you do not twist the hose during the assembly.

(4) Attach the clamp blocks without tightening.

Subtask 20-23-11-917-084-A

C. Tightening Torque Application

CAUTION: WHEN YOU TORQUE THE NUT, ALWAYS USE A SECOND WRENCH TO APPLY A COUNTERTORQUE TO THE FITTING.

(1) Find the correct torque value (Ref. AMM TASK 20-21-12-911-001).

NOTE: To find the correct torque value, you must know the material and the dimension of the parts you assemble.
If the connection has different materials, you must use the torque value for the weakest material.

(2) Get the applicable torque wrench and the applicable wrench adapter for the nut and an applicable second wrench to apply the countertorque to the fitting.
We recommend the tools from the 98F29003000000 WRENCHES-STANDARD TORQUE SET.
(3) Set the torque wrench to the applicable value.
When you use a wrench adapter, you must adjust the value.

Adjustment of the Torque Value

(4) Put the torque wrench in position on the sleeve nut and the countertorque wrench in position on the fitting.

Typical Examples of Connections

NOTE: We recommend that you install the wrench adapter in the same axis as the torque wrench.

NOTE: The torque wrench must always be installed on the nut (female part) and the countertorque wrench on the fitting (male part).

(5) Apply a slow and continuous force on the torque wrench until you have the set torque value.

NOTE: Always pull (or push) at right angles to the handle of the torque wrench.
Try to apply load to the center of the hand grip of the torque wrench.
Pull with fingers only. Do not hold the hand grip.

(6) Double tightening torque

NOTE: The double tightening torque is not applicable for the installation of the plug-in components installed with an O-ring (for example, plug-in unions, manifold plugs and plug-in check-valves).

(a) Torque the union:

torque the nut to the correct value
loosen the nut by one turn
torque the nut again to the correct value.

(7) If applicable, torque the locknut of the swivel bulkhead fitting to the correct torque value (Ref. AMM TASK 20-21-12-911-001).
Hold the fitting with the applicable countertorque wrench and torque the locknut with the applicable torque wrench.
(8) Torque the clamp blocks to 0.2 m.daN (17.70 lbf.in).

5. Close-up
Subtask 20-23-11-917-085-A

A. Put the Aircraft back to its Initial Configuration
(1) Pressurize the hydraulic reservoirs (Ref. AMM TASK 29-14-00-614-002).
(2) If necessary, fill the hydraulic reservoirs:

With a hand pump (Ref. AMM TASK 12-12-29-611-001) or
With a hydraulic cart (Ref. AMM TASK 12-12-29-611-002).

(3) Pressurize the hydraulic systems:

For the Green system (Ref. AMM TASK 29-10-00-863-001) or (Ref. AMM TASK 29-23-00-863-001)
For the Yellow system (Ref. AMM TASK 29-10-00-863-002) or (Ref. AMM TASK 29-23-00-863-002)
For the Blue system (Ref. AMM TASK 29-10-00-863-003).

(4) Make sure that there is no leakage in the repaired area.
(5) Put a red line on the tightened fittings (Ref. AMM TASK 20-23-22-910-001).
(6) Bleed the related hydraulic system:
(a) For the Green system:

Upstream of the engine pump (Ref. AMM TASK 29-00-00-870-001)
Upstream of the PTU (Ref. AMM TASK 29-00-00-870-002)
Downstream of the engine pump (Ref. AMM TASK 29-00-00-870-003).

(b) For the Yellow system:

Upstream of the engine pump (Ref. AMM TASK 29-00-00-870-004)
Upstream of the PTU (Ref. AMM TASK 29-00-00-870-005)
Upstream of the Yellow E-pump (Ref. AMM TASK 29-00-00-870-006)
Downstream of the engine pump (Ref. AMM TASK 29-00-00-870-007).

Upstream of the Blue E-pump (Ref. AMM TASK 29-00-00-870-008)
Downstream of the Blue E-pump (Ref. AMM TASK 29-00-00-870-009).

(d) For the normal braking system (Ref. AMM TASK 32-42-00-870-001).
(e) For the alternate braking system:

Low pressure (if installed) (Ref. AMM TASK 32-43-00-612-001)
High pressure (Ref. AMM TASK 32-43-00-870-002).

(7) Make sure that the work area is clean and clear of tools and other items.

[Rev.10 from 2021] 2026.03.31 22:59:23 UTC