Mercedes W123 High Pressure Power Steering Hose Replacement Repair Guide

Difficulty

Moderate

Steps

Time Required

                          2 hours

Sections

High-pressure Power Steering Hose
4 steps

Flags

Member-Contributed Guide

An awesome member of our community made this guide. It is not managed by iFixit staff.

BackMercedes W123
Full Screen
Options
History
Save to Favorites
Download PDF
Edit
Translate
Get Shareable Link
Embed This Guide
Notify Me of Changes
Stop Notifications

Introduction

What you need

Step 1

              High-pressure Power Steering Hose

Use an open-ended wrench or flare wrench (better) to unscrew the high-pressure tube nut (gold, inverted flare) from Vickers power steering pump. I found an 11/16" SAE wrench fit best.
Unscrew the tube nut from steering gear, using a 2nd wrench to keep the adapter in the gear from turning.

Use an open-ended wrench or flare wrench (better) to unscrew the high-pressure tube nut (gold, inverted flare) from Vickers power steering pump. I found an 11/16" SAE wrench fit best.

Unscrew the tube nut from steering gear, using a 2nd wrench to keep the adapter in the gear from turning.

1024

Step 2

To remove each fitting, secure the outer shell in a vise or such. Use an open-ended wrench or flare wrench (better), to unscrew the mandrel tube from the ID of the hose. It is a normal right-hand thread. Once out, unscrew the hose from inside the shell. That is a left-hand thread, so turn as if you were tightening a bolt to unscrew.
Factory instructions for the fitting may be document “Gates Field Attachable Coupling Installation” (search), but note the shell there screws onto the hose OD with right-hand thread.

To remove each fitting, secure the outer shell in a vise or such. Use an open-ended wrench or flare wrench (better), to unscrew the mandrel tube from the ID of the hose. It is a normal right-hand thread. Once out, unscrew the hose from inside the shell. That is a left-hand thread, so turn as if you were tightening a bolt to unscrew.

Factory instructions for the fitting may be document “Gates Field Attachable Coupling Installation” (search), but note the shell there screws onto the hose OD with right-hand thread.

Step 3

For high-pressure hose, I used SAE 100R5-8, 13/32" ID, 2000 psi, 1-wire (blue jacket). Cut w/ hacksaw or cut-off disk to 21" length.
A better choice might be SAE 100R3-6, 2 fiber braids, 3/8"ID, 0.75"OD, 1125 psi (Gates 6G3HXCTN), since more flexible and still adequate pressure. The factory hose had fibers, not steel wire.
For return, I used Parker 611HT-8, 1/2" ID, 400 psi (black jacket). Another choice is SAE 100R6, 1 fiber braid, 1/2" ID, 400 psi (Gates 8GTHXCTN).

For high-pressure hose, I used SAE 100R5-8, 13/32" ID, 2000 psi, 1-wire (blue jacket). Cut w/ hacksaw or cut-off disk to 21" length.

A better choice might be SAE 100R3-6, 2 fiber braids, 3/8"ID, 0.75"OD, 1125 psi (Gates 6G3HXCTN), since more flexible and still adequate pressure. The factory hose had fibers, not steel wire.

For return, I used Parker 611HT-8, 1/2" ID, 400 psi (black jacket). Another choice is SAE 100R6, 1 fiber braid, 1/2" ID, 400 psi (Gates 8GTHXCTN).

Step 4

Assembly is reverse order. Lubricate the hose OD and ID with power steering oil to make it easier.
Start screwing the new hose into the shell a few turns. It is a left-hand thread so turn ccw. As soon as you have room, push the tube mandrel into the hose ID and turn in 1 turn cw to get it started. Don’t wait until the shell is all the way on or you may not be able to get the mandrel into the hose.
Continue screwing the shell onto the hose (ccw) until the end of the hose bottoms out in the shell, then unscrew 1/2 turn (cw). Then, continue screwing the mandrel into the hose ID until the mandrel bottoms out against the shell. Re-install hose on pump and gear, routing so it doesn’t touch the car’s body.

Assembly is reverse order. Lubricate the hose OD and ID with power steering oil to make it easier.

Start screwing the new hose into the shell a few turns. It is a left-hand thread so turn ccw. As soon as you have room, push the tube mandrel into the hose ID and turn in 1 turn cw to get it started. Don’t wait until the shell is all the way on or you may not be able to get the mandrel into the hose.

Continue screwing the shell onto the hose (ccw) until the end of the hose bottoms out in the shell, then unscrew 1/2 turn (cw). Then, continue screwing the mandrel into the hose ID until the mandrel bottoms out against the shell. Re-install hose on pump and gear, routing so it doesn’t touch the car’s body.

To reassemble your device, follow these instructions in reverse order.

Cancel: I did not complete this guide.

                                                                                      One other person completed this guide.

Author

                                      with 2 other contributors

                    William Grissom

Member since: 06/07/2017

178 Reputation

                                      1 Guide authored                  



                       Badges:
                       8







                                                        +5 more badges

Ebony x - Aug 30, 2022

Hi, I am currently in the process of changing my high pressure power steering line for Mercedes ml270 w163 2001… I was wondering if you could assist with any links or names to parts that may be of any help. The only part I can find online is 400 dollars.

Member-Contributed Guide#

Introduction#

What you need#

#

#

#

#

#

#

Member-Contributed Guide

Introduction

What you need