1976 450SEL revamp 4.5 version

[MitchD]

Gday everyone,
Names Mitch, from Perth Western Australia.
I have a 76 450sel that has been sitting for a couple years, nothing major, just a handfull of leaks in key places, fluids needing changing and a good detail as far as my limited mechanical knowledge has told me.
I have recently found out about the mercedes-benz car club of WA and decided I am going to get involved, which means getting the big rig fixed up and registered (a highly detailed process here in Australia).
A member via facebook put me onto this forum here, so I have decided ill use this thread to keep posted on my revamp and if anyone has any input to give please feel free as my knowledge on cars in general especially ones like this are slim to none.
Studying the haynes manual has given me enough knowledge to move on with fluid changes and such, ill list my plan of attack:
Brand new battery
Dump fuel tank (has been sitting for 2 years)
Change fuel filter
refil tank
Flush radiator
Refill 50/50 coolant mix
change engin oil and filter
Change trans oil and filter
Air filter
Spark plugs and leads
Distributor cap

now there is an issue with some leaking out of the rear susspension and from what I understand the system is hydropneumatic?

I live in the northern suburbs of perth and ideally I would like to find someone with spare time and a love for mercedes vehicles thats willing to share their knowledge and go over the vehicle with me to identify any further problems that I cant with my limited mechanical skills.
Thanks for reading everyone, pics to follow.

[robertd]

welcome to the forum MitchD,
you are in good company in Perth with some very knowledgable members stationed there.
sounds like you are off in the right direction,
good luck and enjoy your project.
RobertD

[MitchD]

Thanks mate, glad to have found this forum, have found a thread on almost everything I have wondered about my car. Hopfully have an update after the weekend, gonna get stuck into it with some of the things ihave found.

[wbrian63]

If the fuel has been sitting in the tank for 2 years, you may have rust. Make sure you do something about that before loading the tank with new fuel. Loose rust will eventually migrate to the filter screen in the tank and obstruct it, giving you periodic issues with stalling or poor performance.

Depending on the # of KM's on the car, I wouldn't rush to service the transmission. If the fluid is nice and pink-ish in color and doesn't smell burned - leave it be. In my early years, I worked as a service advisor at a repair garage. Many, many times I was witness to otherwise properly performing high-mileage transmissions getting a fluid service, only to start slipping a few thousand miles later. This is no guarantee you will suffer the same fate, but if the fluid looks OK - I'd leave it alone.

If your car has auto-leveling suspension in the rear, then (I think) it is a combination of springs and load-leveling shock absorbers. This will involve, in addition to the shocks, a pump on the engine, a tank under the hood, a pair of pressure spheres in the rear, and a height control valve mounted to the body with a link attached to the rear sway bar.

Standard faire 450SEL's didn't come with the 6.9-only true hydro suspension, which substitutes 4 hydraulic rams for the springs.

The shocks can leak, as well as the height control valve. The spheres involve high-pressure nitrogen held in check behind a rubber diaphragm. Over time, the nitrogen migrates through the rubber and is lost to the atmosphere. When this happens, there is no damping available, as hydraulic fluid cannot be compressed. Cars with this malady typically exhibit a "bouncy" ride.

Be very wary of servicing these parts. The fluids in the system are under very high pressure, and releasing them in an uncontrolled manner can result in damage to your car, or worse, yourself. NEVER get under a car in such a manner that if the body were to drop down to the bump stops you would be pinned. It's unlikely with a 450SEL - even if the rear shocks are totally removed, the springs will support most of the weight of the body, but safety is no trivial matter.

You can't drive and enjoy the car if you're flat as a flap-jack.

Welcome to the forum.

[MitchD]

Gday brian,

Cheers for ya explanation of the suspension system, I have been strugling with finding some simple information on it.
I have observed a spot that it is leaking from and will take a couple pics to put up over the weekend, hopfully someone can identify it.

I checked the trans fluid the other week, which seemed quite clear and pink, if I remember the fluid was changed not long before I garaged it so ill probably leave that till last and use the money on more essential bits.

as far as the fuel tank, I have a pic of the dirty fuel I drained out and will post up later, I have already put 20L back in but shouldnt be a problem to drain again. Ill research checking it out aandpost my finding after the weekend.

[Tony66_au]

G'day Mitch,

West Aussie cars shouldn't have bad fuel tank rust issues because of the climate mate but there is a filter where the fuel line runs into the tank itself which will need a clean.

Getting the filter out is another issues because you need a very large socket to get it out and this would be the very first job id do followed by the fuel filter which isnt far from the tank and possibly the connecting hoses to the filter and pump.

1976 makes your girl a K jet yes?

Cheers,
Tony

[MitchD]

Yeah Tony from what I have read its k. To be perfectly honest tho I have no idea what im looking at so couldnt tell ya specifically. If anyone could link me to a thread with good k/d jet info that would be great

[Tony66_au]

You know this site has an online manual yeah?

http://handbook.w116.org/matrix6.htm