600

Hi! Great color. Like my W109 is!

I had to redo my pump twice as the new oil seal failed after 500km due to rust pitting on the shaft. The shaft was grinded to smaller diameter and smaller oil seal used. It's fine now. I had huge issues removing inner neadle bearing from the fan hub. It's was really well pressed in. I send you private message with my phone number. Ready to help anytime.

I used rebuild procedure as described in the updated version of W100 Service Manual. Great description there.

600 #796 (1967 US version)

300SEL 6.3 #1285 (1969 EURO version)

300SEL 6.3 #5346 (1971 US version project)

Hi Filip

Yes please! Pictures of fan rebuild to check my reassembly.Regards Keith.

Hi Filip

You showed us yours,better show you mine. Kept inside under dust cover for 50 years.

regards Keith.

Hi Filip

For a long time I thought I was the only retired mechanic in the world attempting to rebuild a 600 that had been sitting for 50 years.I am obviously number 2.Congradulations.

I am facing most of the same problems you have faced.ATM trying to find article on M-100 site written by fellow Australian Art Love on water pump rebuilds and found your posts.

I did manage to remove original impeller without breaking it, but was then told I needed new one as sealing disc in impeller needed to be replaced to bed in with new water seal.[I probably could have just machined it flat looking back]

I nearly put the copper sided Thrust washer in backwards due to poor wording in the repair manual.

I did put the oil seal in the hydraulic fan hub in backwards, forgot I was doing from the inside.At least I realised before complete reassembly or failure on the car.

Any other traps you can tip me off about?Thanks.Regards Keith.

Thank you. It's never over ... Working on the underside now. New bellows installed in all four corners. Pressure test in progress.

600 #796 (1967 US version)

300SEL 6.3 #1285 (1969 EURO version)

300SEL 6.3 #5346 (1971 US version project)

Very beautiful, congratulations to all the work well done!

Hello.

I promised to post picture of finalized car so here it is.

This was taken during MB club of the Czech Republic presentation on 2025 Car Expo in Prague.

Filip

600 #796 (1967 US version)

300SEL 6.3 #1285 (1969 EURO version)

300SEL 6.3 #5346 (1971 US version project)

Hello.

Let me give you update on my 600. I'm now getting ready for summer season.

Work in progress:

• bellows
• more comfort hydraulics
• rear windows re-seal

ToDo:

• many rubber bushings on front and rear axle to remove knocking on bad roads.

Filip

600 #796 (1967 US version)

300SEL 6.3 #1285 (1969 EURO version)

300SEL 6.3 #5346 (1971 US version project)

Hello.

I just finished rebuild of brake master.

Before

After

Rebuild kit is NLA but you can get the rubber seals from kit AUTOFREN SEINSA D1250.

You will four kits as there is just one seal in the kit. I got one kit for 3 USD only! Made in Spain.

600 #796 (1967 US version)

300SEL 6.3 #1285 (1969 EURO version)

300SEL 6.3 #5346 (1971 US version project)

It took two years but it's moving again. There is still a long list of ToDo. But we have a Czech MB Club meeting next weekend and it's time to roll it out! Wish me luck.

This is a behind the scene foto. It just moved first 30 meters by own power and got a hose wash to remove dust.

I will post proper photo after professional paint care.

ToDo:

replace joint on the steering rod at firewall to get rid of clunking sound

replace steering dumper (there is Stabilus 0948DX available for W100 now)

get headlamps aligned

get wheels aligned

get the right side generator working (I was lucky to get refurbished one from RockAuto!)

replace both regulators with new Bosh F026T02230 electronic version with old-style look

install new rubber boots for parking brake cables

get rid of corrosion at left rear fender (typical for 600)

paint heads of front fender screws at the door opening (gold plating is shiny and it visible)

get new MB star spring to make it stiff during strong wind blow

heating too low (I'm planning to replace temperature regulator with Arduino based system)

AC running non-stop (the same solution like with heating)

AC compressor clutch noisy

power brake booster has sketchy feel on pedal on the top of the move

new wheels as old are 20+ years old

get the clock working or replaced

shifter rod lower busing is shot

600 #796 (1967 US version)

300SEL 6.3 #1285 (1969 EURO version)

300SEL 6.3 #5346 (1971 US version project)

Thank you. I'm gathering a lot of know-how that I'm ready and happy to share. 600 is just a different animal I have to admit that I had no idea about the complexity of the car. I thought it's just a bit bigger W109. I was so wrong. Working on W109 is like pre-school compared to university called W100. On the other hand and as example rebuilding Comfort Hydraulic DIY way is so satisfactory. For example I had no idea that working on 600 hydraulics will need used owen and learning how to bake pistons (see picture of freshly baked piston) :-)... 

Also I would like to thank to many members here that are providing me with help, parts and even a mental support. Many times they are not visible but they are getting in touch with me privately.

600 #796 (1967 US version)

300SEL 6.3 #1285 (1969 EURO version)

300SEL 6.3 #5346 (1971 US version project)

Filip, this is a great project you are pursuing. The title of this thread seems a bit misleading: You do not seem to need any help at all!

It is truly interesting to follow your work, and the resources you have at hand seem like a dream to any hobby automotive restorer.

May update.

It's back on wheels again. Fenders repaired and mounted. AC compressor rebuilt (both bearings and all seals). I'm now waiting for barrier hoses to come from Aeroquip. Firewall at battery was repaired as it was rusted a lot from acid spills.

I’m slowly moving forward with ambient temperature gauge repair. I have successfully rebuilt first piece but it’s time consuming and complex process. I’m now preparing a filling station to speed up the rebuild. Will post details once ready.

Coating

Back on wheels

AC rebuild

Firewall

600 #796 (1967 US version)

300SEL 6.3 #1285 (1969 EURO version)

300SEL 6.3 #5346 (1971 US version project)

Hello.

Some update.

I'm still fighting rust issues in front end (lamp buckets, front bumper holder, battery tray area). Anti gravel unercoating was partially cracked so there were rust spots under it. I will do new coating with Roberlo Hidrotex. I have replaced all three seals for summer air flaps and seals on both heating flaps. 

I have discovered leak at power steering pump. Febi 08711 aka A 000 586 55 46 will cure it later.

AC work is suspended as one Aeroquip hose (FC802-8) is not available in Europe now and will arrive in early May from US!

I’m also considering replacing oil pump tensioner rail with A1161811059 as my original one is missing the plastic pad completely. You know I love removing crankshaft pulley! 

I'm replacing rubber hoses on central locking as the rubber was hard and causing leaks. I had to replace two membranes too.

300SEL 6.3 #5346 (1971 US version project)

600 #796 (1967 US version)

300SEL 6.3 #1285 (1969 EURO version)

Hello.

I'm new rebuilding the receiver drier with new desiccant as I can't use R22 in EU so conversion t R134a is mandatory.

Heater box will get new seals and hoses. Heater blower need new rubber buffers as it's sagging too low and rubbing the box.

Air Conditioning blower switch (on top of the console between the front seats on newer cars) is stuck as the resistor wire is loose. Do you have any suggestion what glue to use? I tend to use high temp epoxy.

600 #796 (1967 US version)

300SEL 6.3 #1285 (1969 EURO version)

300SEL 6.3 #5346 (1971 US version project)

Hello.

I managed to get replacement flap from US! What a miracle.

Now I'm curing rusted floor.

Whole AC was remove so I lost the precious R12 that's not available in EU. I will convert AC to R134a.

It's also great oportunity to remove heater box. I will change blower rubber mounts because the blower wheel is sometimes touching the walls as the rubber is tired.

Also new hoses and gromets will be installed.

My biggest project now is the AC control unit.

All KH elements are resealed now. Chrome levers replaced with new from Thomas Jäkel.

There were many problems. I found one cracked solder on the wire to microswitch connection. Plastic coupling connecting unit with the electrical box was cracked.

Whole vacuum element and bracket assembly for summer air flap closing is missing.

I now manufacturing a replica now using vacuum element from R107 trunk lock.

.

600 #796 (1967 US version)

300SEL 6.3 #1285 (1969 EURO version)

300SEL 6.3 #5346 (1971 US version project)

Working on the summer air flap. You need really long tools!

Unfortunately one of flaps has cracked base. Will model it in 3D a print it on our Prusa printer.

600 #796 (1967 US version)

300SEL 6.3 #1285 (1969 EURO version)

300SEL 6.3 #5346 (1971 US version project)

Just a quick update.

My first rebuild door piston is holding pressure for 2 days already!

New leak developed from suspension switch on steering column. It's not easy to remove the switch, but it's done.

Replacing the port seals is same task as elsewhere. Unfortunately the hole at the bottom of the lever is worn to oval. I'm not aware of replacement available. I replaced the seal on the control rods and set the screws. Let's hope it will hold for some more years.

I got two new OEM seals for fresh air flaps and I'm preparing new silicone seals for the trim now.

Also some rust prevention will be necessary in the air ducts under the flaps.

600 #796 (1967 US version)

300SEL 6.3 #1285 (1969 EURO version)

300SEL 6.3 #5346 (1971 US version project)

Merry Christmas and Happy New Year!

I gave myself a gift. The KH system was pressurized again after almost a year! Let's hope for no leaks.

I still have one more door piston to glue, paint and test. But I was so eager that I just plugged the pipes and opened the valve.

Work on KH till now:

- replaced all port seals in doors and trunk

- replaced all leaking inner seals on switches in doors

- replaced inner seals on one window piston as it was leaking at rod

- clean and rebuild of all door locks including hydraulic pistons and switches

- trunk lock rebuild

- trunk lid piston port seal replaced

- shutoff valve at engine compartment was rebuild

For some valves I had to manufacture new POM plastic inner parts as they were leaking. Now I'm testing various glues to stick window piston valve head. Unfortunately, the companies rebuilding W100 hydraulic for crazy money won't share they know-how. I only got limited instruction to use basic epoxy glue without any specific product recommendation. I'm now waiting for delivery of slow curing liquid epoxy resin that will be tested. I need something that will disintegrate at max 220C as the original Bosch glue so the piston will be rebuildable again if necessary.

I also developed a process to remove port seal brass ring without any damage so you just need to replace rubber square ring. 

Working on 600 is a real joy. But you need a lot of free time. It's so complex and satisfying when done.

Next item on the list:

- climate control panel including outdoor thermometer

- rear window and side windows seals

- tranny speedometer reseal (I bought new drive from Woerle that should cure the well knows problem)

- some welding on the rear and bottom + little respray

- ENJOY THE CRAZY CAR FINALLY!

Regards

Filip

600 #796 (1967 US version)

300SEL 6.3 #1285 (1969 EURO version)

300SEL 6.3 #5346 (1971 US version project)

Hello.

1) Water pump is done. I used my own CNC impeller made of bronze. I can offer it for better price compared to original cast iron.

2) Front main seal is replaced. I had to build some proprietary tools to do it. I'm ready to share it within EU.

3) The crankshaft pulley had a groove that was removed on CNC.

4) Oil/Water wax regulator for fan clutch was resealed as it was leaking. There is a special aluminium seal ring A 189 997 01 40 that is NLA so I had to laser cut it. I still have some available if someone is interested.

5) I bought used Bosh EFEP 385A injection pump test stand. I plan to open the black box of MFI repair and testing. Wish me luck.

600 #796 (1967 US version)

300SEL 6.3 #1285 (1969 EURO version)

300SEL 6.3 #5346 (1971 US version project)