Sequence of repairs for 300E?
 

I did not get the head off the 300E Sunday. In making sure I was prepared, I looked at one of the new head bolts and realized the 12-point hex socket required was not the type in my toolbox. After a couple hours' searching, I found that Snap-On calls them 12mm triple square sockets. At least the extra time allowed me to finish cleaning out the garage.

Here is where I can use some suggestions. I now intend to pull the head next weekend, take to the machine shop Monday, and reinstall the following weekend. I also will replace the serpentine belt tensioner and shock, the water pump, all hoses (radiator and heater), thermostat, as well as flush the green stuff out of the cooling system.
I have 3 1/2 days this coming weekend and 2 1/2 the next.

Is there a particular sequence that will make the entire process easier or flow better?

Not really any sequence that I can think of. Just take your time and try to get plenty of digital pictures if you can. The pics can be used when you go to putting stuff back together.

Re: Sequence of repairs for 300E?
 

First, start by removing the bolts that you can see...............Seriusly though, do you have a repair manual or are you just gonna 'wing it'? That special headbolt socket is merely your first surprize. General knowledge doesn't cut the mustard when working on MB's.

Maybe flush the coolant before the head comes off so you don't flush old coolant through the sparklingly clean head.

Sixto
95 S420
91 300SE
87 300SDL
83 300SD

Head bolt tool
 

Autozone sells the 12 point socket that you need, if you happen to live near a store.

They cost around $10.

Good Luck

head job
 

make sure you replace the valve guides.
Second; Ask the guys in the head shop if they will reinstall your cam and lifter assy after the heads are worked.
Also Mark location of the cam sprocket in relationship to your chain and cam shaft. (so your timing will stay the same.

No kidding Jim, that digital camera has saved my butt a couple of times when pulling laptops apart for relatives.

Cap'n;
I have a Haynes, a Technibooks, and also suscribed to AllData while trying to figure out how to grease the windshield wiper. Can't find any head r&r on the CD. I think I read most of the M103 posts on 'head gasket removal', and 'valve job' while trying to find the name of that socket. After that, to paraphrase Akroyd, I have 1/2 a tank of gas and a pack of cigarettes.
This is my third Benz since I traded my Grand Prix for a 12-yr-old 250S in college in 1978, but the first one I have tried working on to this extent.

Sixto,
This was one of the things that made me post this. I was not sure whether to flush before or after. I now think I will burn a jug of Zerex not only to avoid contaminating the new head, but to keep residual green stuff from drying in the radiator and block since they will remain drained for almost a week. I have not tried a Shout or citric acid flush before, but imagine even that would take some time to rehydrate dried green antifreeze.

Paul,
I wish I had seen this earlier; I called Snap-On when I got up and had one sent 2-day. I don't mind the price of the socket, but I wish I could deduct what I paid UPS last year.

MikeV,
Thanks for the pointers. I did not realize I had to ask to have the cam and lifters reinstalled. I hope I have not gotten ahead of myself, but I already have a set of replacement guides to take to the head shop.

I'd think twice about installing the cam with the head off. I for one prefer to handle the head with all the valves closed just in case I have to put it down quickly.

Sixto
95 S420
91 300SE
87 300SDL
83 300SD

Sixto,

You lost me there.
When I picture a head with no cam, the only way to have all the valves closed (with no extra hands) would be with the head upside down.
What is the advantage to have the valves loose in the head?
I assume you mean put the head down on a work surface; or am I missing some terminology here?

The cam doesn't keep the valves in the head. There are springs and retainers that keep the valves in the head whether or not the cam is in place.

I don't mean to question your confidence but it's strange that you think the valves would fall out if the cam isn't there.

Sixto
95 S420
91 300SE
87 300SDL
83 300SD

Sorry,

I equated not reinstalling the cam with no reassembly at all. A particularly trying night at the salt mine; I should be able to leave work at the front door better. But as of now I am done for the week.

I am accustomed to seeing the 528E arrangement with the rocker arm assembly over the valve stems and the cam underneath. I would find it advantageous to have this type system already installed from a time and learning-curve standpoint.

In terms of setting it down, I stopped at Harbor Freight and picked up a chain hoist, with the objective of inching the head down on the block, allowing ample time to align everything. I have not tried it out yet.
Are my expectations for this chain hoist realistic, or am I in for another learning experience?

I am surprised that no one has discussed whether or not to leave the intake system on the head while removing.

On the later 104 engine, it is common to leave the intake in place and remove it with the head, then remove the intake from the head on the bench. On the 103 engine, I believe it is easier to leave the intake in place. This decreases the number of old, brittle connectors and such that may be broken during disconnection/reconnection.

You will have to get underneath the car to reach some of the intake bolts, but they're not that bad.

Good luck,

Larry,

I am open to either method. As far as old brittle connections, I replaced all the rubber parts about a month ago. I had intended to replace the intake gasket, and did not because 1) I was pressed for time, and 2) I could not easily locate where the last connector on that branch of the wiring harness terminated.
With no worry about brittle connections, would you still leave the intake in the car?

Something else that does not seeem widely discussed is whether to remove the exhaust manifolds from the pipes or from the heads. Since I will be flushing the coolant system, I can douse the nuts with liquid wrench and run them thru a warm-up and cool-down cycle at least twice. This might make removing the manifolds from the heads a more attractive option. What are your thoughts on this?

I personally would leave the intake in the car, but the exhaust on the head, then remove the exhaust on the bench. It would be best to remove the four flange bolts from the exhaust manifolds, then loosen the manifold nuts at the head while the head is tied to the engine. That way you have something to twist against.

Good luck,