Removing and Installing Hydraulic Pump

WM 489819 Removing and installing hydraulic pump








Information

Information





Overview of hydraulic pump

1 - Throttle housing with distributor pipe
2 - Resonance tube
3 - Intake distributor cylinders 4-6
4 - Air-conditioning compressor
5 - Supply tank
6 - Sealing rings
7 - Pulley
8 - Screw
9 - Hydraulic pump

Preliminary work

Preliminary work
1. Remove left front seat.
2. Remove rear wall cover.
3. Remove engine compartment cover.

Removing hydraulic mount

Removing





Overview of hydraulic pump

1 - Throttle housing with distributor pipe
2 - Resonance tube
3 - Intake distributor cylinders 4-6
4 - Air-conditioning compressor
5 - Supply tank
6 - Sealing rings
7 - Pulley
8 - Screw
9 - Hydraulic pump

1. Remove throttle housing and distributor pipe.
2. Remove resonance tube.

Loosen screw-type hose clamps, see -Arrows-, and remove resonance tube -2-.





Intake-air distributor

3. Remove left intake-air distributor.
4. Loosen belt pulley.

Loosen screws on pulley, see -Arrows-.

5. Remove drive belt and pulley.

Unscrew screws on pulley, see -Arrows-, and remove pulley.





Belt pulley

6. Drain hydraulic fluid at underbody connection point.

The following steps must be completed in order to drain the hydraulic fluid:

6.1. Remove rear underbody panel.

Replace fastening nuts -2- following removal.





Removing cover for rear underbody

6.2. Remove underbody panel at the left side.

Replace fastening nuts -3- following removal.





Removing side cover

6.3. Disconnect supply and return line at underbody.

Disconnect supply and return line and collect hydraulic fluid.





Supply and return line

7. Remove the supply tank.

Remove hydraulic fluid from supply tank by suction. Open bayonet lock and remove the supply tank.





Supply tank

8. Disconnect return line at the supply tank/hydraulic pump.

Disassembly tool, universal NR.21

If you do not have a special tool to hand, press the red circlip forward using two plastic spatulas and pull the return line out at the same time.





Return line at hydraulic pump

9. Loosen air-conditioning compressor.

Unscrew screws -2- and move air-conditioning compressor -1- so that the screw -3- can be removed.





Air-conditioning compressor

10. Disconnect feed line at the hydraulic pump.

Loosen feed line -1- (a/f 16). Counter at the connection piece while doing so (a/f 24).





Feed line at hydraulic pump

11. Remove hydraulic pump.

Information: When you remove the drive belt, the drive belt tensioner is lying on the hydraulic pump. The increased strain prevents the hydraulic pump from being removed and inserted, so the tensioner must be turned accordingly. Get another person to help you do this.

11.1. Unscrew the screw at the back of the hydraulic pump.

Remove screw -3-.





Back of hydraulic pump

11.2. Unscrew the screws at the front of the hydraulic pump.

Remove screws -2- and press the drive belt tensioner back at the same time. Remove hydraulic pump.





Loosening and securing hydraulic pump

Installing hydraulic pump

Installing
1. Install hydraulic pump.

Press drive belt tensioner back with the help of another person and insert the hydraulic pump.

1.1. Screw in and tighten the screws at the front of the hydraulic pump.

Tighten screws -2- at the housing.

--> Tightening torque: +23 Nm (+17 ftlb.)





Loosening and securing hydraulic pump

1.2. Screw in and tighten screw at the back of the hydraulic pump.

Tighten screw -3- at the housing.

--> Tightening torque: +23 Nm (+17 ftlb.)





Hydraulic pump

2. Secure feed line at the hydraulic pump.

Secure feed line -1- (a/f 16). Counter at the connection piece while doing so (a/f 24).





Feed line at hydraulic pump

3. Connect return line at the supply tank/hydraulic pump.





Return line at hydraulic pump

4. Secure air-conditioning compressor.

Tighten screws -2- on air-conditioning compressor.

--> Tightening torque: 23 Nm (17 ftlb.)





Air-conditioning compressor

5. Install supply tank.

Pay attention to markings on the catch and on the supply tank, see -Arrow- !





Supply tank

6. Connect supply and return line at underbody.
6.1. Connect supply and return line at underbody.





Supply and return line

6.2. Install underbody panel at the left side.

Replace fastening nuts -3-.





Removing side cover

6.3. Install rear underbody panel.

Replace fastening nuts -2-.

Tighten fastening screws -1-.

--> Tightening torque: 2 Nm (1.5 ftlb.)±1 Nm (±0.5 ftlb.)

Tighten fastening nuts -2-.

--> Tightening torque: 1.5 Nm (1 ftlb.)±1 Nm (±0.5 ftlb.)

Tighten fastening nuts -4-.

--> Tightening torque: 5 Nm (3.5 ftlb.)±1 Nm (±0.5 ftlb.)





Removing cover for rear underbody

7. Install drive belt.





Drive belt

8. Secure belt pulley.

Tighten screws -Arrows-.

--> Tightening torque: +23 Nm (+17 ftlb.)

9. Install left intake-air distributor.
10. Install resonance tube and throttle housing with distributor pipe.

Tighten screw-type hose clamps in correct position.





Installation position for intake-air distributor screw-type hose clamps

11. Fill in hydraulic fluid, bleed the power steering and check for leaks.





Checking steering fluid

Subsequent work
1. Install engine compartment cover.
2. Install rear wall cover.
3. Install left front seat.