vacuum line Mercedes 300sd
 

What all absolutely requires a vacuum line? I am thinking about trying to eliminate it as much as possible and for the essential things redoing the line in a more permanent material. Because I am having a leak somewhere and would like to limit the possibility of it ever occuring again to a far more limited area.

Depending on what you're willing to go without will determine the answer.

However, the only vacuum item thing you NEED is power brakes.

The engine shuts off with vac also, but you can always go under hood and push the STOP lever.

The HVAC system won't work.

The locks will, as they have a separate vacuum system.

Perhaps you can isolate the leak. Yet this takes time and is tedious. Describe your leak symptoms.

Just fix the leak. You have the door locks, the climate & a little in the engine compartment. Diagrams are available online and in the FSM. The vacuum pods under the dash can all be changed with the dash intact (perhaps except for 1).

It isn't a difficult project once you decide to get into it.

Also 1984*
Yea, I can hear a leak behind the climate stuff.. Transmission isn't the quickest rabbit in the getting into gear department either... Occasionally seems to get stuck or limit me to about 35-40 ish. Climate control just kind of comes on when it feels like it after I've pressed the button. The left rear break wore out recently, looked at the right rear, rotor has rust spots on it like it hasn't engaged in a while... While the other got to metal on metal in notime flat. Door locks dont work... But can live without them. Odo stopped but I don't think that's related.

Yea. Either I'll probably have to redo the entire thing. Or try to start with just the necessary things that take the car forward, make it stop and turn off..(basic car stuff) redone and leave the rest undone for a while.

Occasionally, doesn't also shut off occasionally... Can turn it off and pull the key out but it keeps going until I put it into gear.

The last thing I would do is to start pulling vacuum lines without knowing what they are going to. Contrary to some thinking, most of the vacuum lines don't go to any kind of emissions equipment. Most of them are for transmission, fuel shut-off and climate control. Talk about what you are having problems with and many of the forum members can walk you through resolution. You will find that a Mightyvac will be one of your main tools. Many of the problems I had originally were very simple repairs, once I sorted out what to look for and finding a leak usually cured several problems at once. The rubber flex lines at the ends were the usual culprit.

For the shut off, the most usual case is a disconnection of the vacuum lines from the shut-off valve at the back of the Injection pump. Not all that uncommon after a filter and oil change as the lines tend to become disconnected when replacing the filter.

Here is a copy of the FSM: Untitled Document

Any idea what the cost for a mightyvac is? (Also the model number if there is one)
As well as a rough estimate for what it might cost to have a repair shop find/fix the vacuum issues.
Will make it a bit easier for me to weigh the cost/time on everything.... As some would label my schedule as extremely busy. (Full time student, two jobs)

Amazon.com: mityvac hand pump

Many Auto Zoos carry something similar, as does Sears.

Juggling time and repair costs is a tricky business.

Good luck.

Fix your brakes first. Nothing else will matter if you're dead. Cost of mechanic for all you mentioned will be more than your monthly wage. Got wrenches?

Yea, planning on starting with the breaks for that reason. Have wrenches in the truck actually.
Was planning on changing the pads and rear rotors this weekend. Wondering if there is anything else on the breaks that I should look into purchasing.
There is an 85 300sd in a salvage yard by me, got a turn signal from it a couple weeks ago. Any idea what parts are not interchangeable between them?

I don't think you mentioned what year you SD is but everything between 1981 to 1985 will interchange (beyond a few odds and ends). As suggested state your symptoms here and someone should be able to help or offer direction. When I bought my '83 SD one of the issues was she wouldn't shut off when the ignition was turned off - similar to what yours is doing. I tested the shut off valve with a Mighty-Vac (you most definitly need one working on a MB diesel or gas). The problem was the boot was cracked that connected the line to the nipple on the valve.

On your brakes you should also replace the rubber flex lines that go from the hard line to the caliper. Also if you haven't already make sure you have the correct pads and hardware as your SD could have ATE or Bendix calipers. Mine has bendix on the front and ATE on the rear. Always keep the same manufacture on the same axle if you have to replace calipers.

It's an 84 300sd, bought it planning on fixing it up and making it last forever. Knew it was going to be a project when I bought it :) ( out of a field)
Any idea if there is a kit for rerunning the vacuum lines completely. Know there is a diagram of it as I found a couple, is there a part list as well if there isn't a complete vacuum line replacement kit. So I could build my own :)

If they don't make a kit (expecting they don't(but I like to be proven wrong)) someone could probably make a bit of money of selling some lol

Get a list of the issues up in the morning. Have them written on a note pad in my trunk. Have to sleep.

I doubt there is an entire vac line kit anywhere. Usually the rubber parts, connectors, diaphragms, etc. are the parts that deteriorate.

The color coded hard lines are possibly NLA anyway.

Rest up and keep us posted.

The vac lines themselves are plastic and almost indestructible. You will not likely need to change them out. All you need to replace normally is the rubber tube connectors on the plastic vac lines or the vac actuators in the doors. Sometimes one repair will fix everything else - do not be surprised.

Note the vac system under the hood which shuts off the engine is entirely separate from the vac system in the cabin.