W126 HPF1 suspension repair

[Aleksi]

Hi. I wanted to make a thread about my HPF suspension repair project.

I have a w126 with the hpf1 system. I have already replaced all the spheres and cleaned the oil tank and changed the filters. The ride quality improved drastically.

The front struts are leaking and the righthand side dust cup and bumpstop were badly damaged. Here below are some pictures from the restoration of the front right hand strut:

Dust cup rusted because drain holes were clogged by dirt. The car has been coated with rustproofing spray decades ago and its starting to fall off. Ball joint boot was also destroyed.




A heat gun and two wrenches were used to open both ends.


Bottom end of the rod was corroded and had to be treated with acid and zinc paint.



Cleaning and changing the seals.




New bumpstop:

Painted:

Installed:

Part sourcing:

I got new spheres from Niemöller in Germany.

air chamber, rear axle blue | 450SEL/6.9 Mercedes-Benz w116.036 | Niemöller

Air chamber, rear axle blue spare part for your Mercedes W116 on sale. Buy for unit Springs and Suspension used in chassis 116.036 with engine 100.985 | No: F 32 207 | Part number: 126 320 01 15

www.niemoeller.de

F 32 202 : air chamber, left + right + centre front axle red

Here you can order Mercedes Benz vintage car spare parts or you can request a quote for your corresponding spare part.

www.niemoeller.de

Sinterfilter from thomasjj2 on ebay. It can also be cleaned and reused.

Mercedes W116 450SEL 6.9 W126 mit HPF Sinterfilter NEU 1163270091 | eBay

Ich biete Euch hier einen neuen Sinterfilter(NF) für den Druckregler der HPF (hydropneumatische Federung) im W116 450SEL 6.9 und W126 mit HPF / HPF2. getauscht?. A116 327 00 91.

www.ebay.com

Paperfilter is easy to find from several sources.

MERCEDES W116 W123 W126 W140 ORIGINAL Ölfilter | eBay

E-KLASSE W123. S-KLASSE W126. S-KLASSE W140. E-KLASSE W210. S-KLASSE W220. Zustand : Neu.

www.ebay.com

Seal for the tank/regulator was from a Mercedes-Benz dealer.

New dustcup was from thomasjj2 on ebay.

Mercedes W116 450SEL 6.9 W126 HPF Federbein Anschlagtopf | eBay

Auf Wunsch tauschen wir den Anschlagtopf auch am von Dir eingesandten Federbein aus. ich biete hier einen NEUEN Anschlagtopf für die vorderen HPF-Federbeine des W116 450SEL 6.9 sowie der W126 mit HPF1 bis 5/1986 an.

www.ebay.com

New reproduction bumpstops from Roland Merz in Germany.

Anschlagpuffer für Federbein MB 1163270630 1163202513 1163202613 1163203813 1163203919

Anschlagpuffer für Federbein für Mercedes-Benz Sachnummer: 116 320 25 13 - 116 320 26 13 - 116 320 38 13 - 116 320 39 13 - 116 327 06 30

roland-merz-katalog.de

New balljoints (FAG 817 0001 10) from autodoc in Germany.

https://www.autodoc.fi/fag/14458389

Hydraulic hoses were made by a local hydraulics shop.

Strut seals were from a ebay seller but not available anymore. O-rings are easy to get elsewere but teflon rings are a problem.

Rubber mounts can be reworked by Roland Merz but i chose not to:

1163271881 rubber bushing hydropneumatic spring, leg to frame, Mercedes W116 450SEL 6.9, reworked old part in exchange

116 327 18 81 rubber bushing hydropneumatic spring, leg to frame, Mercedes W116 450SEL 6.9, reworked old part in exchange

roland-merz-katalog.de

 

[c107]

This is a really comprehensive write up

 

[Styria]

Thank you for this comprehensive post. It was of particular interest from a number of perspectives. Firstly the cost of the top strut mount, obviously very pricey, but I am pleasantly surprised that re-manufactured items are actually available. Similar sentiments also apply to the rubber bump stop for the front strut. Here in this country those items, even in used condition, are like Gold - that's if one can find them. Unfortunately due to the age of vehicles, to find used items in good condition is almost impossible. You have done well.

As far as dismantling procedures are concerned, the strut bodies are very substantial and heavy duty, but indiscriminate disassembly can result in deformed tubing rendering the unit unserviceable. Well, one doesn't even have to be super careful as they are difficult to separate. Good luck with your efforts. By the look of things, finish winters and road grime certainly play havoc with underside appearance. Regards Styria

 

[Aleksi]

Thank you!
The tubes are ok except for some deep scratches and the struts seem to work nicely.
The car has not been driven during winters after 1980's and doesnt have much rust issues. It might look bad but its just rustproofing and dirt.

Left hand side was done yesterday and here is a picture of the dustcup and dirt:

Location of the washer seal:



This wooden thing helps a lot when installing the ball joint.



My biggest concern at the moment is the teflon seals. I only had two sets of seals for the front struts. I also need to repair the rear struts. If someone knows how to get them please share the information.

 

[Mgz]

hello
can you helop me how to remove this seals

 

[Aleksi]

hello
can you helop me how to remove this seals

Hi. You just need a small hook or some other small tool that fits.

 

[Mgz]

Hi. You just need a small hook or some other small tool that fits. this

Hi. You just need a small hook or some other small tool that fits.

this is one part or tow parts

 

[Aleksi]

O ring is under the teflon ring. I hope this image helps:

 

[Aleksi]

Yes its one part.

 

[Mgz]

thank you very mach

 

[Mgz]

thank you very mach

 

[Aleksi]

Nice! You are welcome.

 

[Styria]

I have had these seals re-manufactured at considerable expense. Have only ever had one failure after rebuilding struts, but have slightly damaged two units on account of damaged tubing and also some broken piston damper rings. Very frustrating as I have been unable to find new replacements. Regards Styria

 

[Aleksi]

That must be frustrating. Used and new old stock struts can be found on ebay but at high cost. And from my standpoint customs and taxes make it even worse when ordering from outside of the EU customs union.

 

[Mgz]

Hello

I have had these seals re-manufactured at considerable expense. Have only ever had one failure after rebuilding struts, but have slightly damaged two units on account of damaged tubing and also some broken piston damper rings. Very frustrating as I have been unable to find new replacements. Regards Styria

Hello my Friendes . I did it for 70

 

[Aleksi]

Hi. I am interested where did you get those teflon seals?

 

[Mgz]

Hi. I am interested where did you get those teflon seals?

cnc machine workshop

 

[Mgz]

I just gave him the old one and he made a copy of it

 

[Aleksi]

Ok. I will try it as well.

 

[Oversize]

Great work!!! Basically NEVER throw out a strut since they can be rebuilt or worst case used for parts. Those that are selling them are trying to make huge profits in a limited market. Makes it rather unfair for someone trying to get their car driving again.