Power Steering Pump: Service and Repair
Removing and installing hydraulic pump
Information on support (holder) for plug-in coupling/pressure line
Install holder -20- with spring band clamp -19- (if not yet fitted) in conjunction with the required new parts.
When installing the holder -20- for the first time, you may also have to replace the line -6- in individual cases.
Component overview (Figure shows tandem pump on 911 Turbo with manual transmission)
Preliminary work
1. Switch off ignition.
Open engine compartment lid. Install protective supports.
2. Remove the pressure pipe -1- on turbo engines (911 Turbo and 911 GT2).
Pressure pipe
3. Remove the complete air cleaner assembly.
4. Slacken drive belt (do not remove it) and take it off the hydraulic pump pulley.
Information
^ Only remove the power-steering pump wheel when the drive belt is completely relieved.
4.1. Loosen three M8 external Torx screws on the hydraulic pump pulley by approx. half a turn.
4.2. Slacken the drive belt at the tensioning roller.
Remove the drive belt at the deflection roller under the generator.
Drive belt tensioning roller
Allow the belt tensioner to slide back to its initial position.
Power-steering pump pulley
4.3. Unscrew three M8 external Torx screws on the pulley and remove the pulley.
Removing and installing hydraulic pump
Removing hydraulic pump
1. Actuate the clutch pedal at least 25 times to depressurize the system on 911 Turbo vehicles with manual transmission.
2. Drain Pentosin from the reservoir.
If you are replacing the reservoir, remove the cap, puncture the strainer and drain Pentosin through the filler opening.
If you want to continue using the reservoir, drain Pentosin - using a shop-made device - through the return connection, from the clutch booster circuit or steering, at the reservoir.
^ Shop-made device: Pull out original return line (for the clutch booster circuit or steering). Shorten this line and connect it to a suitable suction pump.
^ Procedure for draining Pentosin: Connect the shop-made device to the upper part of the reservoir instead of the original return line and drain Pentosin (using a suitable suction pump).
3. Remove hydraulic lines on the upper part of the reservoir.
3.1. Remove pressure lines -1- on the upper part of the reservoir (only fitted on 911 Turbo vehicles with manual transmission).
Hydraulic lines at the reservoir
3.2. Disengage pressure lines from the clip -2-.
3.3. Loosen return line -3- on the upper part of the reservoir.
Removing return line
3.3.1. For this purpose, push disassembly tool Nr.21 between the return line and the red circlip and release it (by pressing the tool against the red circlip), while at the same time pulling the black line to the right. -arrows-.
4. Unclip the return line/hose at the holder for the reservoir (one clip at the back of the reservoir).
5. Open the plug-in coupling on the pressure line (variant 1 or 2).
Opening plug-in coupling (variant 1)
5.1. Variant 1: Remove the lock and then loosen (unscrew) the plug in coupling.
Turn the screw -9- while loosening the coupling. Counter at the hexagon on the plug-in coupling -10- when doing this.
5.2. Variant 2: To access the plug-in coupling on vehicles with a support (holder) -1-, loosen the spring band clamp -4- (using a suitable pair of pliers) and slide it (up) out of the holder area at the same time.
Plug-in coupling with support (variant 2)
Then, bend up the holder -1- at the top and loosen (unscrew) the plug-in coupling as described for variant 1.
5.3. Collect hydraulic fluid in a container.
5.4. Remove collar of holder and screw from the pressure line.
6. Remove reservoir.
Detaching reservoir
6.1. Detach the reservoir. For this purpose, loosen two fastening screws (M8 Torx) on the reservoir -arrows- and one M6 screw (securing reservoir to holder) -arrow-. The screw on the holder -arrow- can be fitted on the left or right side.
Fuel cooler
6.2. Remove the fuel cooler in order to access the rear fastening screw on the reservoir. For this purpose, remove the screw -3- on the holding clamp and remove the fuel cooler. Do not open fuel and refrigerant lines.
6.3. Disengage the reservoir from the hydraulic pump and remove it. Soak up (collect) any remaining fluid with a lint-free cloth.
Removing screws and removing hydraulic pump from the bracket
7. Loosen three M8 Torx screws and one M6 Torx screw -arrows-. Remove the hydraulic pump from the bracket (spare part designation for carrier).
Installing hydraulic pump
Re-fit or replace the following parts when replacing the hydraulic pump:
^ Short pressure line (adapter) on hydraulic pump. -> Tightening torque: 35 Nm (26 ftlb.)
^ Holder (support) on hydraulic pump.
^ Pressure line between the reservoir and hydraulic pump on 911 Turbo vehicles with manual transmission.
Fitting hydraulic pump and tightening fastening screws
1. Fit the hydraulic pump, move it into installation position and tighten the fastening screws -arrows-.
-> Tightening torque: 23 Nm (117 ftlb.)
-> Tightening torque: 10 Nm (7.5 ftlb.)
Pressing reservoir with new O-ring into the hydraulic pump and fitting fastening screws
2. Press reservoir with a new O-ring (coated with Pentosin) into the hydraulic pump (power-steering pump) and fit the fastening screws -arrows-. The screw on the holder can be fitted on the left or right side.
-> Tightening torque: 23 Nm (117 ftlb.)
-> Tightening torque: 10 Nm (7.5 ftlb.)
Fuel cooler
3. Position fuel cooler -1- and tighten the screw -3- on the holding clamp.
4. Fit the return line at the reservoir.
Return line at reservoir
5. Clip in the return line/hose at the holder for the reservoir (back of the reservoir).
Caution
Clutch pressure lines on vehicles with manual transmission can break (due to vibrations) unless they are secured (to the reservoir) with the clip.
^ Escaping Pentosin can ignite on the hot exhaust system.
-> Ensure that the clip is seated correctly and that the pressure lines are fitted securely in the clip.
Fitting clutch pressure lines on 911 Turbo vehicles with manual transmission.
6. Fit the clutch pressure lines -1- and engage them in the clip -2- on 911 Turbo vehicles with manual transmission. Check that the clip is seated correctly and that the pressure lines are fitted securely in the clip.
-> Tightening torque: 13 Nm (9.5 ftlb.)
-> Tightening torque: 20 Nm (15 ftlb.)
7. Fit (screw together) plug-in coupling for pressure line (short pressure line to power-steering pump).
Install the holder -1- (variant 2) and fit the pressure hose -6- at the plug-in coupling.
7.1. Insert the collar of the holder (for the pressure hose) into the plug-in coupling and tighten the screw.
Counter at the lower hexagon on the plug-in coupling while tightening the screw.
-> Tightening torque: 30 Nm (22 ftlb.)
Installing holder 1 (variant 2)
7.2. Install the (new) holder -1- (variant 2) and fit the pressure hose -6- at the plug-in coupling.
7.2.1. Push rubber ring -3- onto the plug-in coupling.
7.2.2. Fit (new) holder -1-. Ensure that the rubber sleeve (on the short pressure line) is not damaged and is positioned correctly in the holder -1-.
7.2.3. Fit (new) fastening screw -2- with an internal Torx screw T40 (instead of the old external Torx screw). Tightening torque: 23 Nm (17 ftlb.).
Use a 1/4-inch socket-wrench insert (change-over ratchet with articulated piece and the required extension) when the engine is installed (for easier access).
7.2.4. Fit the spring band clamp -4- on the pressure hose -6- or on the holder -1-.
7.2.5. Fit the pressure hose -6- at the plug-in coupling (insert it until the plug part engages in the collar of the holder).
7.2.6. Position the spring band clamp -4- so that it is on the four stop lugs (on the holder -1-). It must also be easily accessible in case it needs to be opened at a later time. Lever/pull off the blue relief ring in this position so that the clamping force of the spring band clamp -4- takes effect.
Subsequent work
1. Fit the pulley on the hydraulic pump (three screws/tightening torque: 23 Nm (17 ftlb.)).
Fit and tension the drive belt.
2. Install the complete air cleaner.
Pressure pipe
3. Install the pressure pipe -1- on turbo engines (911 Turbo and 911 GT2).
Caution
Risk of material damage if too much Pentosin is used or if Pentosin gets onto the coolant hoses when filling or topping up.
^ Only fill Pentosin into the supply tank.
^ To avoid overfilling and thus overflowing, always observe the specifications for checking hydraulic fluid from the power-steering system and clutch booster circuit.
^ Multiple steering operations (maneuvering) and/or actuating the clutch with the engine switched off will change the fluid level in the engine-compartment supply tank! The fluid level rises. In this case, the engine must be run for approx. 20 seconds immediately prior to the fluid level check.
^ If coolant hoses come into contact with Pentosin, thoroughly clean them with water IMMEDIATELY.
^ Replace visibly swollen coolant hoses!
Pentosin reservoir in engine compartment
4. Fill Pentosin hydraulic fluid into the tank in the engine compartment.
Bleed the steering hydraulic system and check for leaks.
5. Bleed the clutch high-pressure hydraulic system on 911 Turbo vehicles with manual transmission. For this purpose, press the clutch pedal approx. 10 times while the engine is running.
6. Set the correct fluid level in the Pentosin tank (in the engine compartment). Observe the following preconditions:
^ Start the engine and run it at idle speed for approx. 20 seconds. Switch off the engine.
^ Wipe off the dipstick.
^ Close and then re-open the cap. The fluid level should be in the designated "Cold range" (Min./Max. level at 20 °C). Top up with Pentosin if necessary. Do not add too much Pentosin! The fluid level must not exceed the "Hot max" marking when the engine is warm!