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Just secured a 450 SEL 6.9 after bit of a chase (years)

Started by andrewk, 18 October 2022, 07:38 AM

gurrier

Hugely interesting thread for even such as myself with a 350SE- keep up the good work.
1973 350SE

BCK1963

Andrew,
regarding the hydraulic oil system: There is a little filter located underneath the valve unit on top of the oil reservoir.
I had changed mine when I removed the reservoir for cleaning.

Interested to hear what the crystalline crap in the fule line will turn out to be. Did you already do solubility tests? You won't get rust through the GC column :-).
Is it just by chance or do 6.9s have a particular attractivity for chemistry-related folks?

    Bernd
Bernd

1976 Merc 6.9   Magnetit blue

rumb

The engine wire harness I repaired by cutting it off back along the fire wall. After removing sheathing I cut the wires all offset a bit from each other.  I then used non-insulated butt crimp connectors (they are smaller diameter than insulated ones) and covered in shrink tubing.

To take apart the  harness you need to work from the ends. Removed the connector housing and unsolder the pins. For the Bosch fuel injector connector and boot you can buy those on autohaus.com and elsewhere.  New pins and sockets are avail from MB

Take photos and make drawings of everything.

https://www.autohausaz.com/pn/1287013003

Re-assemble by making the butt connectors and then slide new sheathing on as you go and branch out to the other legs with smaller tubing. The re-solder the end connectors.

These are the tubings still avail from MB:
N040621005200
N040621007200
N040621008200
N040621012200
N040621016200
N040621022200
N040621025200

the 4-5 from last digits are the size.


I have extra lengths of most wire colors if you need some. Let me know the  colors and lengths you need.
'68 250S
'77 6.9 Euro
'91 300SE,
'98 SL500
'14 CLS550,
'16 AMG GTS
'21 E450 Cabrio

andrewk

Quote from: gurrier on 05 January 2023, 05:19 AMHugely interesting thread for even such as myself with a 350SE- keep up the good work.
Thank you!
Quote from: BCK1963 on 05 January 2023, 06:24 AMAndrew,
regarding the hydraulic oil system: There is a little filter located underneath the valve unit on top of the oil reservoir.
I had changed mine when I removed the reservoir for cleaning.

Interested to hear what the crystalline crap in the fule line will turn out to be. Did you already do solubility tests? You won't get rust through the GC column :-).
Is it just by chance or do 6.9s have a particular attractivity for chemistry-related folks?

    Bernd

Hi Bernd, everything that goes through the GC/MS gets filtered. I learned this the hard way after a few "failed" columns at $800 a piece. The material seems organic but looks awfully like rust. We have access ICP-MS too given our involvement with battery chemistry, so any solids that are not soluble in organic solvent will end up going to the ICP lab... Iron is a bad word in our lab most of the time.

I think the problem solving which is learned from chemistry practice is really useful when working on cars. Given you need to solve many of the same issues, just in a different context. Also, older Mercedes are really quite simple; you can follow a problem from start point to end point or backwards without obfuscation by software. Of course the reality of these things is not as simple. Why did it take me 2 hours to change the little filter in the HPF regulator? Learning that it has an allen key in the end of the bolt to hold the threaded part while you undo the nut... after I wrangled with it for considerable time. I think it had never been changed, as the bolts and fittings looked and felt untouched, the oil coming out of the filter was black - even after changing 5-6 litres with fresh Febi oil. Plenty of hydrocarbon cleaning later and it was shiny new. Check out this filter:
1979 450 SEL 6.9 (#5532) - silbergrün metallic

andrewk

Quote from: rumb on 05 January 2023, 11:27 AMThe engine wire harness I repaired by cutting it off back along the fire wall. After removing sheathing I cut the wires all offset a bit from each other.  I then used non-insulated butt crimp connectors (they are smaller diameter than insulated ones) and covered in shrink tubing.

To take apart the  harness you need to work from the ends. Removed the connector housing and unsolder the pins. For the Bosch fuel injector connector and boot you can buy those on autohaus.com and elsewhere.  New pins and sockets are avail from MB

Take photos and make drawings of everything.

https://www.autohausaz.com/pn/1287013003

Re-assemble by making the butt connectors and then slide new sheathing on as you go and branch out to the other legs with smaller tubing. The re-solder the end connectors.

These are the tubings still avail from MB:
N040621005200
N040621007200
N040621008200
N040621012200
N040621016200
N040621022200
N040621025200

the 4-5 from last digits are the size.


I have extra lengths of most wire colors if you need some. Let me know the  colors and lengths you need.

Thank you! I just added the tubing to my Classic Center order.

Which wire gauge and type did you use? I have a lot of wire and cable on hand but i'm not sure it is the right size or number of conductors/type of insulation for the application.
1979 450 SEL 6.9 (#5532) - silbergrün metallic

rumb


Which wire gauge and type did you use? I have a lot of wire and cable on hand but i'm not sure it is the right size or number of conductors/type of insulation for the application.
[/quote]


I have original wire stripped from a spare parts wire harness.  The gauge of wires are shown on all wire diagrams.

'68 250S
'77 6.9 Euro
'91 300SE,
'98 SL500
'14 CLS550,
'16 AMG GTS
'21 E450 Cabrio

raueda1

I went through this but I don't think I posted the details.  So, these may help.  I just looked at old harness and used same gauge wire torn out of another car.  Nothing special about it though maintaining the look is certainly nice.  Cheers,

-----------------quick edit to clarify more:
The pins are looking DOWN onto the connectors.  The index tab on the plugs is shown.  I made it so the whole thing could be unplugged next time I have to pull the engine (hopefully never, but who knows?).  That plug is just build arouund the standard MB 6-pin plug.  The harness has 7 wires so I just used a single pin plug for one of them as illustrated.  Dimensions are from the point where the wires exit the main wiring loom.  The black cover was just pvc tubing, not shrink stuff.  I did use shrink tubing on a couple places.  You can see it on the pic.  Doing this may be slightly preventative.  I found that  LOT of the wires had bad or cracked insulation.  Just a problem waiting to happen.
-Dave
Now:  1976 6.9 Euro, 2015 GL550
Before that:  1966 230S, 1964 220SE coupe, 1977 Carrera 3.0

andrewk

Quote from: raueda1 on 05 January 2023, 08:02 PMI went through this but I don't think I posted the details.  So, these may help.  I just looked at old harness and used same gauge wire torn out of another car.  Nothing special about it though maintaining the look is certainly nice.  Cheers,

-----------------quick edit to clarify more:
The pins are looking DOWN onto the connectors.  The index tab on the plugs is shown.  I made it so the whole thing could be unplugged next time I have to pull the engine (hopefully never, but who knows?).  That plug is just build arouund the standard MB 6-pin plug.  The harness has 7 wires so I just used a single pin plug for one of them as illustrated.  Dimensions are from the point where the wires exit the main wiring loom.  The black cover was just pvc tubing, not shrink stuff.  I did use shrink tubing on a couple places.  You can see it on the pic.  Doing this may be slightly preventative.  I found that  LOT of the wires had bad or cracked insulation.  Just a problem waiting to happen.

THANK YOU very much. This is essentially what I had planned to draw up and document, but you have really got every detail needed to rebuild the harness on your drawing - it saves a huge amount of time. I'll check some Bosch part numbers for each type of connector and post them. These old wiring harnesses are definitely a hazard, especially the K jetronic system components and safety fuel cutoff.

This evening I opened up the first aid kit / fuel tank sender cover and found some rust at the top of the tank I'll take it out over the weekend and will take to a local radiator shop who can sort the tank properly. Will rebuild the fuel level sensor and clean out the boot at the same time, checking for rust and anything else which might need attention.
 All things are coming together now - i'm hoping to have the car running in 2-3 weeks. This is incredibly exciting. A 3+ year chase is now feeling very much worthwhile.

Thank you everyone for your assistance - I could not do this without your knowledge and guidance.
1979 450 SEL 6.9 (#5532) - silbergrün metallic

raueda1

Quote from: andrewk on 06 January 2023, 10:42 AMTHANK YOU very much. This is essentially what I had planned to draw up and document, but you have really got every detail needed to rebuild the harness on your drawing - it saves a huge amount of time. I'll check some Bosch part numbers for each type of connector and post them. These old wiring harnesses are definitely a hazard, especially the K jetronic system components and safety fuel cutoff.

Thank you everyone for your assistance - I could not do this without your knowledge and guidance.
Glad it's helpful.  FWIW, I found the connectors to be pretty robust, especially the ones with round pins.  They seem to be glass filled melamine or bakelite or something like that.  Most of mine got reused after cleaning up, desoldering etc.  Then a few came off a parts car.  I wouldn't have any qualms about reusing them unless they're very discolored, cracked etc.  But if you get new that's always best!  I did replace all the rubber boots, they don't fare as well.  Cheers,
-Dave
Now:  1976 6.9 Euro, 2015 GL550
Before that:  1966 230S, 1964 220SE coupe, 1977 Carrera 3.0

andrewk

Quote from: raueda1 on 06 January 2023, 11:33 AM
Quote from: andrewk on 06 January 2023, 10:42 AMTHANK YOU very much. This is essentially what I had planned to draw up and document, but you have really got every detail needed to rebuild the harness on your drawing - it saves a huge amount of time. I'll check some Bosch part numbers for each type of connector and post them. These old wiring harnesses are definitely a hazard, especially the K jetronic system components and safety fuel cutoff.

Thank you everyone for your assistance - I could not do this without your knowledge and guidance.
Glad it's helpful.  FWIW, I found the connectors to be pretty robust, especially the ones with round pins.  They seem to be glass filled melamine or bakelite or something like that.  Most of mine got reused after cleaning up, desoldering etc.  Then a few came off a parts car.  I wouldn't have any qualms about reusing them unless they're very discolored, cracked etc.  But if you get new that's always best!  I did replace all the rubber boots, they don't fare as well.  Cheers,

The connectors seem a bit brittle on my car and the rubber parts are perished. I'd like to just get them replaced as it's not a major expense for peace of mind. I guess we have a hot climate here so that probably has not helped their cause. Waiting for Bosch to get back to me

It turns out a lot of the rubber vacuum parts on the top of the engine are still available. I have almost finalised the parts order, will give an account of which parts go where once they arrive and I can take some pictures for you all.
1979 450 SEL 6.9 (#5532) - silbergrün metallic

andrewk

I removed the fuel tank yesterday and took it to a shop for repair and coating the inside. This is the junk I found in there. Should have it back within two weeks. I am going to replace the fuel level sender, just waiting to see if MB Classic Center have it in stock.

During the removal of the brake lines, I found one of the fittings had been a bit wrecked in the past. Unfortunately, I couldn't get enough traction or grip on it with the flared wrenches and it caused further damage. During this process I damaged the hard line and had to cut it - so i'm going need to replace it. First mistake of the whole job so far. I still haven't been able to separate the hard line fitting and the flexible hose coupling, no matter how hard I try. I cleaned it, added penetrating oil to the threads and it just would not budge. Not pleased with myself, and left after an 8 hour day feeling pretty defeated. If anyone has a spare rear left hand hard line, please let me know - i'll buy it from you. Else i'll have to have it made, but don't have a good template (i.e. the old line) to have a new one custom made.

Also, ATE no longer make the pistons for the brake calipers - so i'll have to either find NOS or an alternate manufacturer.
1979 450 SEL 6.9 (#5532) - silbergrün metallic

daantjie

Don't feel too bad 8)  we've all been in "rounded nut/bolt purgatory" before, it's part of the "fun" ;D
Daniel
1977 450 SEL 6.9 - Astralsilber

ramiro

About the brake lines just get some CuNiFer copper lines for the brake line , in europe you can get them preflared with the needed lenght, you can then bend them with your hands super easy and they will never rust.

Jan S

Those fittings are a nightmare! One of the fittings on my car was ... argh! I gave up and had to bring it to a workshop. They used a considerable amount of heat to separate.

Please tell us more about the tank, the cleaning and coating process. I've heard mixed stories when the tank has been coated ... some say that after a while the coating falls off and lands in the fuel system. It all depends on the quality of work and the coating process, I guess. Hence would be interesting to learn more about this.
1975-mod W116 450 SE with 6.9 engine

andrewk

Quote from: Jan S on 08 January 2023, 07:17 PMThose fittings are a nightmare! One of the fittings on my car was ... argh! I gave up and had to bring it to a workshop. They used a considerable amount of heat to separate.

Please tell us more about the tank, the cleaning and coating process. I've heard mixed stories when the tank has been coated ... some say that after a while the coating falls off and lands in the fuel system. It all depends on the quality of work and the coating process, I guess. Hence would be interesting to learn more about this.

Lots of swearing, sweat and basically tears. No dice. I'll get the hot air gun onto it and see if some yelling helps.

So, the tank cleaning is being done by a radiator shop.

First step as follows; tank is cleaned with a basic (NO ACID!) degreaser solution to remove the fuel varnish and polymerised junk. Some rust goes along with it. Then this process is repeated then pressure washed hot, followed by immediate cold water rinse to slow down the oxidation process as the metal is now exposed to the air (and water).
Then, the tank is sealed up, submerged in a large tank of solution with some kind of surfactant and corrosion inhibit (looks very similar to radiator coolant) then pressurised - any air leaks will form bubbles which are then marked, repaired etc.
Following that, the tank is cleaned again with degreaser and solvents (I am guessing something with a ketone group; methyl ethyl ketone, acetone etc) to remove any previous coating. Then it is dried in an air stream. Following that, the tank is filled with a product called RedKote which is a solution of some kind of polymer, a dye and acetone. Then that mixture is washed around the tank by agitation then drained.
The method is shown here; https://www.ftrs.com.au/redkote/usage/

It is compatible with all fuels including E85 and high methanol content racing fuel which cause problems with other coatings. Just as long as there isn't any acetone, methyl ethyl ketone or dichloromethane etc in there - it should be fine.

Here is some information from the safety data sheet (via Manufacturer's website - https://www.ftrs.com.au/redkote/dry/sds.pdf):
Screen Shot 2023-01-09 at 12.59.10 pm.png



1979 450 SEL 6.9 (#5532) - silbergrün metallic