1974 450sl From the start

[Genbiltstein]

I purchased a 450sl from a coworker of mine. He handed it over to me completely stripped out ready for painting. I had her painted last year and slowly I have been putting her back together. Because I didn't take it apart it has been a nice puzzle.
Most of the parts are in place with the exception of half of a dozen or so. I discovered little surprizes like the fuel tank filling area filling up with water. A masonry drill bit and hand rotated deep enough down the drain pulled the rust out.
The Gas flap locking mechanism vacuum actuator was toast so I need another one. They look to be easy to rebuild. However finding the single diaphram I guess is another story.
I had starting and running issues.
The connection Needed to be cleaned next to the distributor. New Spark plug wiring was in order. Cleaning that adjustable air valve with the big screw did the trick as well.
She also wants to not start when she has been sitting hot. I need to put a fuel pressure tester on her. I don't believe theso called 9th injector has anything to do with it. It runs fine.
The wiper motor runs a bit slow but I attribute it to poor contacts at the connection so I cleaned then. I found them a bit corroded.
The relay for the blinker/ flasher would run fast so I located it behind the steering wheel deep inside the dash. It needs to be pulled out and the contacts where it plugs back into simply needs cleaning. I wiggled it and the blinking 4 ways ran slower.
It was a difficult rewiring the hazard/flasher switch because the prior owner did not record the wiring. Very difficult to find the sequence online.
I won that battle.
The Aircondition compressor is running but I have no cold air. I get hot air. Always hot air. The dash was replaced before.
As I understand it the compressor shouldn't run if there is no freon in the system. I could be wrong but this is a mercedes. I will run the AC system again and feel the lines to be sure if they are cold.
The fuel lines are too close to the muffler pipe on the driver's side and I want to believe it might be contributing to hard to start problems when she sits after a good run. The distance is about 6 inches. there is surface rust on the fuel lines where the exhaust lines are. This is where you would be sitting in the car.
I have all four rotors coming in. Brake pads coming in. Reinstalled 2 grommets at the master cylinder because they were long past serviceable. The master cylinder was leaking fluid for years. Smaller diameter grommets and not the larger type.
All I need is rear axle seals and after that she will be road worthy.
It's been an interesting adventure.

[JimFreeh]

What a project.

Kudos for your tenacity.

Jim

[LUVMBDiesels]

Yes, great job. We need pix!
You should do a complete write up and post it here and submit it to "Star" magazine and to "Hemmings Sports and Exotic Cars" They always have a write up of a major restoration.

[Genbiltstein]

she was rescued from the "the motor pool" You know the ad everyone hears about. My coworker stumbled upon it. I bought it off of "somewhere" and I picked it up from him. He put alot of work into it by his own right. Half of the body is from a 380sl '82 I believe.
I replaced the rear rotors, brake pads tonight. Tomorrow it's the front rotors and brakes.
Sway bar links two weeks ago. This D jet runs pretty good. I am finding out just how much Mercedes Benz, BMW, VolksWagen and Volvo were in cahoots with Bosch.
If you can believe it the injectors are not leaking around the lines or seals. I thought I have seen it all when it comes to vacuum lines but mercedes has proved me wrong on this one. Theirs on this cars have proved to be as supple as the day they were made. This car is 35 years old.
I have seen scores in the automotive trade that were a can of worms once you break a seal on one vacuum line. Some cars had the stiff plastic kind. I will never work on those again.
This car is teaching me a lesson even though I was stationed in Germany three times. I command the language to a fair degree. They have a saying over in Stuttgart where Mercedes are made, "Heilig Blach" Holy Metal. I knew the saying for years but I guess its sinking in.
I have the Euro Bumpers on but I need to take them off in the future and refinish them inside and out.
Ran into a guy who has a '79 450sl. One of those respected wheeler and dealers. He got the car in a business deal. No title. "Says to me make an offer".
Soft Top is in great condition, Man I need that soft top. Wheels good, Motor runs well, Most of the body looks good. To be honest this car is in better shape than the one I started out with.
Another guy has a hard top and will wheel and deal me. I am a mechanic.
He has a Porsche Carrera '87.

I am into automotive electricity. Been turning wrenches since 81 when as a private in the Army. Retired from the service and now teach automotive technology.






I will be sending a picture of the car soon.

[Genbiltstein]

When I bought this car its been a discovery and still is. You never know what previous owner's have done. This is what I found.
The fuses in the panel were not in the correct rated slots. Amazing that there is instructions and color codes to match the fuses. It is difficult reaching and reading these fuses. Best thing to do is get a digital camera and take a snapshot.
Do yourself a big favor and inspect what's in your fuse panel.

Under the shifter I found and corrected the wiring You are looking at where the red wire was connected to.

I soldered up a red fuse because I didn't have one. I turned that bad boy into a mini fusable link rated for the amperage I needed. The silver filament is what's needed. The copper is nothing but a connection to the end of the fuse.

[Genbiltstein]

Rust is more than skin deep. This one has it but for the most it is surface rust. All the shock mounts are free of rust. Where the soft top lays down has zero rust.
As said before most of the relay problems I have experienced is mostly where the relays "plug into" Clean the contacts and 90% of the time you will not have to replace the relay.
Pin 87 is the business end of most relays. To be sure about it you can always check pin 30. A relay is nothing but an electronic switch. Power from 86 to 85--- will send voltage through 30 and 87. That is the science of it. Pin 85 is ground and ground can be used to control the activation of 86---85 but most of the time it is 86 gets voltage and 85 is the ground circuit. If you are not american it is called earthing.
More often than not I verify voltage then straight to ground I go. Clean off the terminal to chassis ground and the battle is won.

Mercedes is a strange animal to say the least. They are built to last. I have experience with BMW, European Ford, Their version of GM, Opel. Mercedes are that good. Their attention to detail amazes me. For the life of me I cannot understand how a car company can thrive in competition.
the local people in Germany would tell me a car is an investment that you keep over time. Now I personally know.

[Genbiltstein]

A few things to note. The owner before me chopped the 5mph bumper mounts right off the car. I will grind them flush and you will never know mouns were ever there.

[Genbiltstein]

I am one lucky Mercedes owner. I only put 100 miles on the car but the brake line on the passenger front has seen much better days.




The Brake pads is another area I am lucky. The rotors are still serviceable. That is the edge of a ziptie I tried to use as reference. It didn't come out as I wanted in the picture. The brake pads were as thin as 10 sheets of paper. Speaks volumes of former owners.




There is a wire that comes from the headlight assembly. Is it for the brights?

[Genbiltstein]

Because I noticed the flasher relay flashing way too fast I decided to reach way back into the dash behind the steering wheel. I pulled it out and pulled off the case. This is one of the reasons why Mercedes Benz flasher relays cost so much.

I need to find out why the front blinker lights are not working.

There is nothing wrong with this one but my curiosity got the better of me like it always will. I am not a mercedes relay expert but there are subcomponents like resistors, transistors, a coil and contacts. You can always open these things up and inspect the small circuit cards on the top and the bottom. To clean the circuit boards take a pencil eraser and lightly go over where you see corrosion.

[Genbiltstein]

I am not one to drive around a detailed engine. What I drive is clean but not detailed. Detailing a Mercedes engine compartment can teach you the car. One of quickest ways to know a strange car is work on it. I am noticing alot of PeachParts do as well.
You can tell the master cylinder has been leaking for some time. The rubber grommets were deteriated. Evidence of brake fluid contamination is everywhere.

[Genbiltstein]

I made the mistake of ordering the wrong Master cylinder from a vender. It must have been British because the brake lines faced outward instead of inward. J




I rebuilt the original master cylinder with the parts from the one that came in. You are looking at the new Master cylinder with my old parts.

The brake cylinder valves were competing with the rust that gathered over the years. This is what happens when you come across an old Mercedes that has never been flushed.
The red arrow indicates where the rust happened. On the springs. Rust particles would then fall and get pushed forward to the next seal. This seal caught some debris and wouldn’t seal. My brake pedal would go to the floor.

The blue arrow indicates the seal that was pushed around due to the rust.
The Master Cylinder itself inside was as good as new. Another testament to Mercedes Benz as this is a good example of corrosion control. There is a liner installed by the factory The cylinder seals glide along this liner.

The purple arrow indicates a stop that you must loosen to pull out the master cylinder valve.
If you rebuild one of these have faith that the master cylinder should withstand corrosion. Save some money and order a quality rebuild kit. Replace the black seals that you see here and be done with it.

Don't make the mistake of not replacing the dust seal. Now I have to remove the master cylinder and install it.

[Genbiltstein]

The Blinker lights are working because I installed the front turnsignal lights. The blinker relay works most of the time now on normal timing. However there are times in the morning it wants to "turn signal really fast" Not near as fast as without the front turn signal lights missing.
To correct this I need to get a tube of Die-electric (sic) I misspelled but the proninciation is there. Disconnect the relay from under the dash. Clean shoot some Die-electric grease and install. I can almost garantee the signaling problem will end.

I don't think the spark plugs are firing until the oil pressure switch is closed. I believe there is a relay to check out. Any help would be appreciated.

[Genbiltstein]

An update in the turn signal lights. It turned out that the 4 way hazard switch relay was from the wrong year. I replaced the '83 and installed the correct '74. The turn signals and flashers are running on completely normal time. The resistor had something to do with it I am sure.

I stumbled upon why the old bird was hard to start. After reading and sifting through much information on this forum, I have learned alot.
Turns out that the auxilliary "ninth" injector was flooding the engine. When I disconnect the electrical connector she started just fine.
I have to go back and find out if it is the temp switch energizing when the car is too warm.

[Genbiltstein]

The dreaded Chain death rattle!

Happened to me when I was driving from a stop and accelerating. I knew it was typical for 450sl (s) to lose timing chain guides. If it weren't for peachparts I would have not exactly known nor expected it to happen.
It started to rattle on the driver's side when I was "on the gas a bit". I heard it and backed off the throttle.
Applied the throttle a bit again and the rattle returned. I opened the hood and sure enough I could hear the rattle coming from under and deep inside the driver's side front.
I nursed her home and while doing so never heard the rattle again. I even opened the throttle and still did not hear it.
I ordered a new chain.
Timing chain guides (all of them except the crankcase guides)
Timing chain tensioner.

I have replaced a timing belt on a tundra and this doesn't look to be as complicated.

[eddennis]

I stumbled upon why the old bird was hard to start. After reading and sifting through much information on this forum, I have learned alot.
Turns out that the auxilliary "ninth" injector was flooding the engine. When I disconnect the electrical connector she started just fine.
I have to go back and find out if it is the temp switch energizing when the car is too warm.

Can you tell me where the 9th injector is located and describe exactly how you disconnected it. I have the same problem with hard hot restarts and would like to see if this works on my old bird. Thanks eddennis@yahoo.com