Power Steering Pump: Service and Repair
Removing and installing hydraulic pump
Preliminary work
Preliminary work for removing hydraulic pump
Warning:
Danger of injury and material damage when using Pentosin.
^ Risk of skin irritation and damage to skin.
^ Damage to hoses and wiring.
- Wear protective gloves and goggles.
- In the event of contact (eyes or skin), wash immediately with water.
- Collect emerging Pentosin.
- Use caps to protect the wiring against soiling and damage.
- Clean hoses and wiring immediately.
Information:
Cover engine openings (e.g. intake openings, crankcase, lines, open containers, etc.) with a cloth to prevent dirt and foreign bodies from getting into the openings.
The air-conditioning lines on the compressor do not need to be opened in order to remove the hydraulic pump. After removal, place the air-conditioning compressor on a suitable protective support (e.g. foam or neoprene).
1. Raise the vehicle.
2. Drain hydraulic fluid at the underbody connection point -arrows- in the rear sill area on the left.
Pressure and return lines
2.1. Dismantle underbody panels in the center (left side).
2.2. Remove plug-in couplings from pressure and return lines. Release the plug-in couplings using special tool loosening tool 9780 and pull them apart.
Releasing plug-in coupling (as of model year 2009)
To separate plug-in couplings, follow the instructions.
Close the hydraulic lines -1, 2- again immediately after draining them (pressure and return lines).
Make sure that the pressure and return lines are not confused and that the connecting couplings lock with an audible click when you connect them.
2.3. Extract residual fluid from the supply tank with a pump.
Collecting Pentosin
Dispose of extracted Pentosin according to the relevant regulations. Lay a cloth under the tank to collect any emerging Pentosin.
3. Remove air cleaner housing.
4. Loosen drive belt -1- and remove pulley.
4.1. Loosen screws -4- on the pulley.
4.2. Turn the tensioner -3- clockwise at the hexagon (a/f 30) using a ring wrench -2- and take off the belt.
4.3. Allow the tensioner to slide back to its initial position.
Removing the pulley
5. Remove the resonance tube. This is necessary in order to remove the return line at the hydraulic pump and the rear fastening screw.
Resonance tube mounting
Removing and installing hydraulic pump
Removing hydraulic pump
1. Remove hydraulic pump (hydraulic pump/supply tank assembly).
1.1. Disconnect pressure line -1- at the hydraulic pump. When detaching the pressure line -1- (a/f 16 mm), counter at the connection piece (a/f 27 mm).
Hydraulic pump/pressure line
Unscrew two M8 Torx screws -2-.
1.2. Disconnect return line to the reservoir for the hydraulic pump (release and pull it out at the same time).
Return line and holder on pump
Disassembly tool, universal NR.21
If you do not have a special tool to hand, press the circlip -center arrow- forward using two plastic spatulas or an open-ended wrench (a/f 12 mm) and pull the return line -right arrow- out at the same time.
Unscrew one M6 Torx screw on the back, rear fastening point -1-.
1.3. Close off the return bore on the reservoir -2- with a stopper -1-.
Closing off return bore
1.4. Remove the hydraulic pump/supply tank assembly.
Installing hydraulic pump
1. Insert hydraulic pump and secure it at the front and rear. Fit pressure and return lines.
1.1. Insert the hydraulic pump/reservoir assembly into the vehicle.
Screw in two M8 Torx screws -2- on the front of the hydraulic pump and one M6 Torx screw on the back (rear fastening point).
Hydraulic pump/pressure line
Tighten M8 Torx screws. - Tightening torque: 23 Nm (17 ftlb.)
Tighten M6 Torx screw. - Tightening torque: 10 Nm (7.5 ftlb.)
1.2. Secure pressure line -1- to hydraulic pump. Counter at the connection piece (a/f 27 mm) when tightening the pressure line -1-.
- Tightening torque: 35 Nm (26 ftlb.)
1.3. Remove stopper from the reservoir and fit return line to the reservoir -arrow-.
Hydraulic pump return line
Subsequent work
Subsequent work after installing hydraulic pump
1. Fit pulley -4- and drive belt -1-. Pay attention to rolling direction of previously used belts.
Fitting pulley and drive belt
1.1. Check once again that the drive belt is positioned correctly on the pulleys.
2. Fit the resonance tube.
3. Install air cleaner housing.
4. Connect the pressure and return lines to the underbody if necessary -arrows- (if you have not already done so after draining the fluid).
Make sure that the pressure and return lines are not confused and that the connecting couplings lock with an audible click when you connect them.
Pressure and return lines
5. Fill hydraulic fluid (Pentosin) into the supply tank, bleed the steering system and check for leaks.
Reservoir - as of model year 2009
6. Remove protective covers.
7. Fit underbody panelling.