Power Steering Pump: Service and Repair
WM 489819 Removing and installing hydraulic pump - PDK and manual transmission
Tools
Technical values
Information
A tandem hydraulic pump -1- is installed on vehicles with manual transmission, while a solo hydraulic pump -2- is installed on PDK vehicles.
The hydraulic pump -1 and 2- is removed and installed together with the supply tank (as an assembly).
Solo and tandem hydraulic pump
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.
1. Press the clutch pedal at least 25 times to depressurise the system (pressure accumulator/high-pressure hydraulic system) on 911 Turbo vehicles with manual transmission (an increase in clutch pedal pressure will be clearly felt).
2. Raise the vehicle => 4X00IN01 Lifting the vehicle.
3. Drain hydraulic fluid at the underbody connection point -arrows- in the rear sill area on the left.
Pressure and return lines
3.1. Dismantle underbody panels in the centre (left side) => 519319 Removing and installing cover for centre underbody.
3.2. Remove plug-in couplings from pressure and return lines. Release plug-in couplings using special tool loosening tool 9780 and pull them apart.
Releasing plug-in coupling
To separate plug-in couplings, follow the instructions => 4X00IN Plug-in couplings for hydraulic lines - as of model year 2009.
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.
3.3. Extract residual fluid from the supply tank with a pump.
Collecting Pentosin
Dispose of extracted Pentosin according to the relevant regulations. Place a cloth under the tank to collect emerging Pentosin.
4. Remove air cleaner housing and (Y-shaped) pressure pipe.
=> 242519 Removing and installing air cleaner housing - section on "Removing"
=> 214119 Removing and installing pressure pipe - section on "Removing"
5. Remove the throttle housing.
=> 244219 Removing and installing throttle housing - section on "Removing"
6. Remove the oil filler neck on vehicles with manual transmission. Then cover (close off) the opening on the crankcase immediately.
7. Loosen the drive belt -1- and remove the pulley.
=> 137819 Removing and installing drive belt - section on "Removing".
7.1. Loosen screws -4- on the pulley.
7.2. Turn the tensioner -3- clockwise at the hexagon (a/f 30) using a ring wrench -2- and take off the belt.
7.3. Allow the tensioner to slide back to its initial position.
Removing pulley
8. Remove the generator on vehicles with manual transmission.
=> 272219 Removing and installing generator.
This is necessary because otherwise it will not be possible to remove the return lines at the tandem pump (not enough room).
Removing and installing hydraulic pump - PDK transmission
Removing hydraulic pump - PDK transmission
1. Remove hydraulic pump (hydraulic pump/supply tank assembly).
1.1. Disconnect the pressure line -1- at the hydraulic pump. Counter at the connection piece (a/f 27 mm) when detaching the pressure line -1- (a/f 16 mm).
Hydraulic pump/pressure line
Unscrew two M8 Torx screws -2-.
1.2. Disconnect the 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 -middle 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 - PDK transmission
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 the pressure line -1- to the 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 the stopper from the reservoir and connect the return line to the reservoir -arrow-.
Hydraulic pump return line
Removing and installing hydraulic pump - manual transmission
Removing hydraulic pump - manual transmission
1. Remove hydraulic pump (hydraulic pump/supply tank assembly).
Place an absorbent, lint-free cloth under the lines that are disconnected to soak up emerging Pentosin.
1.1. Disconnect the pressure line -1- at the hydraulic pump. Counter at the connection piece (a/f 27 mm) when detaching the pressure line -1- (a/f 16 mm).
Hydraulic pump/pressure line
Unscrew two M8 Torx screws -2-.
1.2. Disconnect the pressure line -1- at the pressure control valve -2-. Use the loosening tool 9780/1 (size DN 6) to release the plug connection and pull out the released line -1-.
Return lines and clutch pressure line
To release the plug connection, press in special tool 9780/1 at the correct position (from above and with the blue handle pointing in direction of travel).
In other words, the 60° chamfer on the loosening tool 9780/1 must be facing the 60° chamfer on the connector (line -1- ). Never lever the plug connection with the loosening tool 9780/1.
1.3. Disconnect the return lines -3 and 4- at the tandem hydraulic pump (from the generator side) - with the generator removed. Disconnect means: Release (press the black circlip forward/towards the tandem pump) and pull the line out at the same time. Disconnect line -3- and then line -4-.
Release the return lines -3 and 4- using disassembly tool, universal NR.21.
If you do not have a disassembly tool to hand, press the relevant circlip forward using two plastic spatulas or an appropriate open-ended wrench (for line 3 and 4 with different wrench sizes) and pull the return lines -3 and 4- out at the same time.
To remove the return line -3- at the tandem pump, disengage this line at the holder on the right side of the engine if necessary.
1.4. Close off return bores on the hydraulic pump using suitable stoppers.
1.5. Unscrew one M6 Torx screw on the back, rear fastening point -3-.
Hydraulic pump/rear fastening point
1.6. Remove the hydraulic pump/supply tank assembly.
Installing hydraulic pump - manual transmission
1. Fit the hydraulic pump and secure it at the front and rear. Fit the pressure and return lines.
1.1. Fit 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 the pressure line -1- to the 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 stoppers from the tandem pump and connect the return lines -4 and 3- (in this sequence).
Return lines and clutch pressure line
Connect the pressure line -1- at the pressure control valve -2-.
Check that the plug-in couplings are locked correctly.
Pull on the lines (at -1- on the connector) to check that the couplings are locked correctly (push and pull gently in axial direction).
Subsequent work after installing hydraulic pump
1. Install the generator on vehicles with manual transmission.
=> 272219 Removing and installing generator.
2. Install the oil filler neck on vehicles with manual transmission.
3. Fit the pulleys -4- and drive belt -1-. Pay attention to rolling direction of previously used belt.
Fitting pulley and drive belt
=> 137819 Removing and installing drive belt.
3.1. Check once again that the drive belt is positioned correctly on the pulleys.
4. Fit the throttle housing.
=> 244219 Removing and installing throttle housing - section on "Installing".
5. Install (Y-shaped) pressure pipe and air cleaner housing.
=> 214119 Removing and installing pressure pipe - section on "Installing".
=> 24251900 Removing and installing air cleaner housing - section on "Installing".
6. Connect the pressure and return lines to the underbody if necessary -arrows- (if you have not already done so after draining the fluid).
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.
7. Fill hydraulic fluid (Pentosin) into the supply tank, bleed the steering system and check for leaks.
Position of supply tank - as of 2010 model
On vehicles with manual transmission, bleed the clutch high-pressure hydraulic system by pressing the clutch pedal many times (approx. 10 times) when the engine is running.
=> 48020150 Checking power-steering fluid level.
8. Remove protective covers.
9. Fit underbody panelling => 519319 Removing and installing cover for centre underbody.