[RAZ9922]

EDC Re-build DIY

Firstly, EDC rear dampers are a simple dare I say “primitive” design.

Nothing fancy about them at all.

The main cost of these units comes from the “Body” design.

This makes the non-availability of a repair kit even more annoying.

Facts I found during my “Re-build”:

With 209.000 Km use on my unit, the main Rod is in good condition.

No groves, no scares.

There are only 4 replaceable items.

1.The top Rod-seal (that’s the one that leaks)
2-3. The O-ring with the Nylon coil (Looks like a bog-standard Item to me)
4.The inner tube Ring

Once the spring is removed, replacing these 4 items should not take longer then 30 min incl. cleaning everything (I used alcohol, and then re-assembled all with a little CHM fluid.)

Special tools required: None, a vice and a Plumbers Pipe wrench was all I had to remove the top collar.

Special settings or adjustment:

To be honest, I could not think of any adjustment on the rears.

The two solenoids Valves have only 3 wires going to them.

I believe these are 12v X2, plus one Ground.

If you give 12V to the solenoids they open, cut the power and they close.

Oil viscosity, amount of Oil is set by design so nothing we could change there.
(Unlike Motorcycle forks, where you can set the damping with the oil thickness, thicker Oil = stiffer damping.)
I had a damaged rear-EDC damper with 4000 miles use in the shed one solenoid was broken due to Trolly jack slipping by the pervious owner( don’t you just love Ebay?)

Just changed the entire Rod assembly into my old body, no leaks all seams fine.

Perhaps the people that do the Re-Build could offer a seal-Set.

That could help our M5 Drivers in the US, Australia???

The fitting is NOT a big issue in my eyes.


Best regards

Raz

(Sorry for the Photo, only done with my Mobile)

 

[Sebring NL]

Where did you get the seals?

 

[RAZ9922]

Where did you get the seals?

I used the entire Rod- assembly from the damaged unit I had in my shed.

Even with only 4000 miles on the clock, I could imagine that the top seal worn itself in with the Rod it was fitted to originally.

By changing the lot, I have avoided a leak (older Rod with newer seal.)

If you read Mikes EDC rebuilding Thread, they can source the Original seals from boge.

(I am pretty sure, Boge uses the same seal for All there shocks with the same Rod-diameter, like some 520’s 525’s.)

So if the Re-building Company Mike found, is too busy to deal with all of us, how about offering the seals to the more “adventurous” Home mechanics like us?

At least the owners with leaking Rear Shocks could be back on the road in a short time.

And sending a few seals to Australia or NZ would be a lot cheaper as well.

Just my two cents..

Best regards

RAZ

 

[farrell]

Raz
With your comments isolated to the rears, I don't think you have
have said anything controversial.
A few have rebuilt the rears in the past in Sth America, Australia & Garcia
who is back in Nth Carolina.
Durability was still an issue from what I understand...

As oe parts, the rears last at least twice as long as the fronts.
The fronts are the main problem & always were imho.

The rods ovalise as they wear in extreme long term usage....worth checking !
Solenoids do fail on the fronts but its rare on the rears.
Damper tube bodies do rot beyond economic repair.
They can come apart quite easily, or they can be near destroyed in the dis-assembly process.

Rear damper removal is not a problem if you have the tools.
Constantly removing the dampers & putting them on & off & on off due to
short term failure is not a solution imho.

But.....
For the diy'er out there working on his own car, prepared to chance his time
on assembling the "untested as a unit" hydraulic parts is one thing.
And the best of luck to you of course.:applause:

I would not be happy to do it & I would not / could not inflict that on any of the
owners cars I work on.
I could not take on the public liability of doing it or the aggro of doing a job
twice or more.

Cheers
Farrell

 

[Sebring NL]

Faz

I think this project should be regarded as a test, just as London Mike's project.

Ofcourse, nobody wants the hassle of taking them off again, but thats what testing is all about ( you are the last person Í'd have to explain that to sir )

Let's see what Raz can come up with.

When I first inquired about the EDC shocks rebuild after I concluded the SLS 3.6 rear shock wouldn't be impossible to rebuild ( my dad is an industrial constructor and can do anything hydraulic plus has access to virtually any tool or testcase) the thing I heard was from people on the board that it would be impossible to "weld " the front units shut again..

I didn't understand the construction at that time nor did I have an EDC shock handy but if this is a matter of seals and input shaft ovalising, I think there are more than enough chances to set this straight.

After all, I still haven't heard any sound reason why its any different from any other hydraulic and if the seal availability problem is solved, whats the remaining hurdle?

Wout

 

[RAZ9922]

Hi, Farrell
“I could not take on the public liability of doing it or the aggro of doing a job
twice or more.”

Fair comment

My problem was;

On a Friday late afternoon, I discovered that my left hand rear shock was leaking like mad. With a Mot appointment firmly booked for Monday morning, my options where, shell we say “Limited”.
Holding my breath and wait for the outcome of the London Mike’s and Cyrus long-term test (My respect to these Gentleman for there dedication and effort :applause
Was not an option at this stage.

All I am saying is, I was in trouble and "that’s" how I got out of it!

If a £20 money outlay and 2 hours labour in total buy me 2-3 Months driving?
(Till the Test is completed and orders form us mere mortals are accepted.)
I can drive the car without causing more damage to expensive parts.
And NOT having CHM running down the Rear Disk Brake comes as a “Bonus”.

Best regards

Raz

 

[farrell]

Raz
Thats all good.
I saw where you were going with your post & felt it had some foundation.
I hoped that I made that clear but not as anything commercial.
I think a certain person takes every post I make in the complete derogatory
& counters it as such.

Its becoming rather tedious.

Cheers
Farrell

 

[Sebring NL]

Its easy to misread intentions on an internet board.

If anyone has beef with me, phone me.

 

[RAZ9922]

In 1980 (my last year as an Apprentice with BMW, back home in Germany) my Master told me;
“Boy, not even at the headquarters can they put a 3.0Si engine into a 525 (E12, with Carburettor )”h:

The only person, believing in my little project was a 15 year old school leaver who just started his apprentice ship with us at that time.

It has taken six weeks, for the two of us to build a complete wiring loom from start to finish. (Bosch’s D-Jetronic had 115 Cables and every single one is white).

The fun was short lived, as I was asked by our company director to sell my car in 1981 or at least park that “Thing” away from BMW premises.
:crying:
Why?
One customer complained that an “Old” 525 form “one of the Mechanics” left his brand new 528i (E28) standing at the lights. :grinyes:

He demanded to have his 528i fixed or have his money back! grrrrrrr

I had to give up working on Cars (as an occupation) almost 10 years ago (Blood Condition) now and then the “Urge” to do it my self’s still there.lovelove
Even more so, if I am told ” Boy, it can not be done”.

I personally do not feel offended by “Youngsters” (Sebring NL may forgive a 50 year old man for this expression :cheers if they question my “believes” or do not agree with “my way of doing things”.
After all, People like him keep the M5 alive, and if he knows something I don’t know I am more then happy to listen (and learn). :3:

Best regards

Raz

 

[davidoli]

Its easy to misread intentions on an internet board.

If anyone has beef with me, phone me.

I agree Wout .....it is often difficult to read the tone / emotion of a statement expressed in the written form !

I'd like to have beef with you or perhaps a joint ....... chill guys , chill !

 

[raymondw]

In 1980 (my last year as an Apprentice with BMW, back home in Germany) my Master told me;
“Boy, not even at the headquarters can they put a 3.0Si engine into a 525 (E12, with Carburettor )”h:

And that is exactly what BMW Motorsport gmbh did so from the mid 1970's for a select group of 'happy few'. These so called 'one off' special's were more common as one may think and from time to time one car shows up for sale. Eventually these activities resulted into the E12 ///M535i in late 1979. With 220bhp this car was significantly stronger then any E28 untill 1984 when the 535i/M535i came out. So yes, it could be done and in fact BMW did so themselves.

For the rest, I am one of those persons who shells out 2500 Euro for new suspension parts rather (HD91, thus no EDC) then overhauling them simply for reasons of reliability/stability. But nevertheless, you have proved that it can be done. :cheers: But can it be done in an industrial process?

 

[RAZ9922]

Hi, Raymond

Considering that my “bodge Job” yawnnnn was done in my drive way, with a 180 euros worth of Hobbyist Toolset from a super mart?

With a specialised suspension work shop, how much can you archive there?
:dunno:

As an example;
If you would buy some Normal Front Boge inserts for lets say a 535 (there are around 70 euros a pop) and cut them open. I would not be surprised if you would find some components that are very similar to our “Hi-tech” version.
The main Rod diameter is quite common to most E34 front units as well.

So one would assume that the Top seals would share a common size also.

Some may say” Yes, but the fronts are welded units?”

The solution to that is quite simple as well,

You cut the top off, just below the weld and cut a fine tread into the shock absorber body. Now you can use an “End Cap” like you use on the Rears or you might be able to modify the standard caps that are used on the normal 520,525, 535 front legs to locate the Inserts.

All I am saying is;

The EDC dampers (front or rear) where designed by Humans.

Build by Humans.

There is nothing “Magic” about them, and "no", none of the components are
“Hand-pre-chewed by Tibetan Monks” ether I am afraid. :grinyes:

Best regards

Raz

 

[farrell]

Raz
The method of cutting below the top cap & threading is one that is fraught with tolerance issues, not least of all maintaining the correct squish along the damper axis & tight concentricity of the part to the damper rod.

I think Ray is just highllighting that as a commercial approach repeatability
is key.
This takes jigs & manufacturing control process as we all know.
The main EDC project is one where we have high expectations.

What you achieved was pretty cool with such limited resource & none
of us would say otherwise:thumbsup:

:cheers:
Farrell

 

[Sebring NL]

Faz

How is the welding problem for the front struts solved in the main EDC project?

 

[RAZ9922]

Parts list, Prices and source of seals to repair a set of leaking rear EDC dampers

Main Seal Kit:

First Part would be the Simrit seal kit: OMS-MR 18,00 25,30 3,0 PTFE GM201
Simrit Part No.: 24127305
(An alternative would be the HENNLICH S31-18x25.3x3.2)
Second Part would be the O-Ring : 42x3
Third Part is the Nylon spiral above the 42x3 O-Ring.
Plus the top seal (wiper ring to keep the dust out)

Parts required to re-seal both rear EDC dampers:

2X RC18-25.5-3.2-170-B BS117 £5.42 each

2X PM0425-30SP-VP £1.13 each

2X WR18-285-6MC-R £1.84 each

2X RM0420-30-N70 £0.21 each

Supplier:

FPE Ltd.

www.fpe-ltd.co.uk

[email protected]

 

[E34_nut]

I would really like to give this a go

Hi Raz.

I live in Australia and have an E34 M540i LE (with EDC) that has one leaky rear shock. I have recently replaced the fronts with new units. To participate in "Sportslines exchange program" will cost me around UKP300+ in freight alone plus an extra 10 days in shipping time. The rebuilt units are still less expensive than new units, but only by 30 or 40%. I'm guessing the savings are much more significant in the UK.

I am more willing to buy the seals and try to repair my rears.

Are the rear shocks gas pressurised like the fronts, or is the pressure for these shocks purely provided by the pump up front ?

When I open the bleeder valve on the LAD regulator, how much oil comes out ?

Do you think the parts you mentioned above, will fit in my shocks ?

Part Numbers for the rear shocks in my car.
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You're talking less than UKP20 + freight + oil - 5days shipping time. You have no idea just how attractive and idea that is ! :1:

Can I please confirm that these parts are proposed for the fronts.

Main Seal Kit:

First Part would be the Simrit seal kit: OMS-MR 18,00 25,30 3,0 PTFE GM201
Simrit Part No.: 24127305
(An alternative would be the HENNLICH S31-18x25.3x3.2)
Second Part would be the O-Ring : 42x3
Third Part is the Nylon spiral above the 42x3 O-Ring.
Plus the top seal (wiper ring to keep the dust out)

and these parts are the parts required for the rears

Parts required to re-seal both rear EDC dampers:

2X RC18-25.5-3.2-170-B BS117 £5.42 each

2X PM0425-30SP-VP £1.13 each

2X WR18-285-6MC-R £1.84 each

2X RM0420-30-N70 £0.21 each

To check the solenoid-valve function, do the solenoids provide an audible click when power is applied to them ?

Does the EDC Computer provide 5V or 12V to control the valves ?

Thanks, Reg.

 

[E34_nut]

Contact details typo

Parts required to re-seal both rear EDC dampers:

2X RC18-25.5-3.2-170-B BS117 £5.42 each

2X PM0425-30SP-VP £1.13 each

2X WR18-285-6MC-R £1.84 each

2X RM0420-30-N70 £0.21 each

Supplier:

FPE Ltd.

www.fpe-ltd.co.uk

[email protected]

Just in case anyone is thinking about FPE as a source of parts to solve rear EDC seal problems, there's a typo in the email address provided by RAZ9922.

It should read [email protected] just as in the URL

Regards,

Reg.

 

[Stevie]

He has not mentioned the parts for the fronts, that is a description of parts for the rears, the bottom actualy being a list.

Can I please confirm that these parts are proposed for the fronts.



and these parts are the parts required for the rears



To check the solenoid-valve function, do the solenoids provide an audible click when power is applied to them ?

Does the EDC Computer provide 5V or 12V to control the valves ?

Thanks, Reg.

 

[E34_nut]

2 parts lists or 1 ?

Hi Stevie
I agree that this looks like a list of parts to rebuild the top seal of a set of rear EDC shocks.

Parts required to re-seal both rear EDC dampers:

2X RC18-25.5-3.2-170-B BS117 £5.42 each

2X PM0425-30SP-VP £1.13 each

2X WR18-285-6MC-R £1.84 each

2X RM0420-30-N70 £0.21 each

I agree the last 3 references in the list below, look like generic descriptions of 3 of the parts in the top seal assembly, but I'm not sure how you reach the conclusion that the information in the first 3 lines of info below "is a description of parts for the rears". I don't know much about seals so I'm starting from a low level of knowledge.

When RAZ9922 wrote "Simrit Part No. 241....." & "Hennlich S31....." & "Simrit seal kit: OMS-MR .....", aren't these references to specific parts manufactured by a specific manufacturer, rather a generic description of a seal ?

If they are generic descriptions of one of the parts in the top seal assembly, can you please help me understand what a description such as "OMS-MR 18,00 25,30 3,0 PTFE GM201" is telling me ? Are we talking about a seal made from PTFE with an OD of 25.30mm, an ID of 18.00mm with something that is 3.0mm and something else that conforms to GM201 ? As you can probably see, I'm clutching at straws, but I'd like to understand what it all means if you know and have the time to explain it.

Main Seal Kit:

First Part would be the Simrit seal kit: OMS-MR 18,00 25,30 3,0 PTFE GM201
Simrit Part No.: 24127305
(An alternative would be the HENNLICH S31-18x25.3x3.2)
Second Part would be the O-Ring : 42x3
Third Part is the Nylon spiral above the 42x3 O-Ring.
Plus the top seal (wiper ring to keep the dust out)

Thanks,

Reg.

 

[JohnR]

Ras, do you know where I can get these parts in America?
Thanks!!
JohnR:byee55amg