I have a 1980 300TD and the hi, lo, and bi level blower doesn't work. The defroster works fine and so does the AC. Someone from here recommended I check the vaccuum lines. I read somewhere else that the main vaccuum line is a green line and under the hood (see pic) it is not connected. There is another fitting to it that is also disconnected. I checked various other vaccuum lines under the hood and there is no vaccuum going to them at all. The cruise control also doesn't engage. I'll post a few pics of the engine. Maybe someone can see something missing as a main source or direct me where to look next.

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I was working on it some more and noticed this which seems to be an air pump? Then the next pic is of a connector which was disconnected. Even when connected it does nothing. I checked it for power and I'm getting a strong negative and on the other terninal it is also registering negative, but not as strong. I'm confused right now.

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the round yellow thing is a check valve. You should have a vacuum line running to it from the large vacuum hose between the pump and brake booster.

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Dave
1983 300D Daily Driver

Right, the yellow thing is a vacuum check valve for the door locks and the vac tank in the trunk above the fuel tank.

the green line is for the heat/ac system.

both systems may have been disconnected because of vacuum leaks.

get a Mity-Vac, it will be your friend in chassing down vac leaks.

there are 2 lines going out the rear of the yellow check valve, one going to the vac tank and the other going to the L/F door. L/R, R/F, R/R doors have a vac actuator for the door locks. the fuel door and trunk also have one.
there are 2 yellow lines that run under the carpet to these actuators. red stripe = lock side, green stripe = unlock side.

the air pump thing, looks like your auxillary water pump for the heater. maybe the plug connector is for the pump.

Charlie

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there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works

I had no idea that I have power locks and they work. It appears that there are several vaccuum lines just sticking out of the fire wall disconnected. I've been told that this is not the original engine in the car either. Should I just get another T or two and put them in line and see if that works? If you look in the one pic you can see that there is one T in that large line, but there are 2 or three other lines disconnected. I've seen other cars with a line coming out of the air cleaner, but mine has a plug in the top. What else does the vaccuum system operate on these cars other than the door locks, climate control system, and cruise control? Only the door locks work and they are slow to go up and down. I also heard the ignition works off of it. The car does not shut off right away. I have to take out the key and put it back in for the car to turn off.

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Well, your locks work, so they are getting vacuum. Because that is not the original engine, it will be interesting to diagnose.
The vac system shuts down the engine in addition to what you've mentioned. So it would seem there is a leak somewhere, not surprising. The vac lines going to the item on the cam cover can be removed and the resulting open connections can be plugged, this may be part of the problem.

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83 SD

84 CD

There is supposed to be some logic to the vacuum system ' tree'.. and the check valves..
so if you have leaks in the system on non important things like the door locks.. it will not disable the brakes and turning off the engine... so do not just install ' t ' fittings willy-nilly with no regard for that concept.

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1980 240d ,

chain elongation, cam marks reference:
http://www.peachparts.com/shopforum/showthread.php?threadid=10414

http://www.peachparts.com/shopforum/diesel-discussion/305365-9-degrees-chain-stretch.html

evap fin cleaning:

http://www.peachparts.com/shopforum/showthread.php?t=156207&highlight=evaporator

A/C thread

http://www.peachparts.com/shopforum/diesel-discussion/297462-c-recommendations-mb-vehicles.html

that aux water pump is probably bad. (most are) if you leave it connected, it can burn out your climate control computer. that big thing next to it is the evil servo... have fun.

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

Your 4th pic shows some leakage on the left side of one of the hoses. It should be totally dry.

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1985 300D 198K sold
1982 300D 202K
1989 300E 125K
1992 940T

"If you dont have time to do it safely, you dont have time to do it"

"The democracy will cease to exist when you take away from those who are willing to work and give to those who would not."

Is there a list or a link to one that tells you which color vaccuum line corresponds to what function? It seems Mercedes was really consistent with their wiring for vehicles!

Mostly, yellow/red is for door locks and trunk reservoir, green/yellow is for HVAC, brown is vac for the ignition switch and brown/violet is for the shut off actuator. Black from the bottom of the VCV is a vent, another black coming from the top of the VCV goes to the automatic transmission, but I don't see that.
Your car could be anything, however, due to a different engine and perhaps a PO swapped out some lines from what was handy, they're all the same size.
Pull back a bit and take a pic of the main vac line and where the lines from there go and the stuff on the cam cover.

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83 SD

84 CD

I started to tee off a couple of lines to see if there was a leak anywhere and then nothing worked. I then disconnected those newly connected lines and at least the car shuts off now. When nothing worked, I lost pressure to the brakes and pumped them a few times and blew a hole in a rusted line. Now I have to replace them too. I'll search a little and see if anyone knows what size brake lines to put in it. I LOOKS simple enough that I can do it myself.

Can someone please take a look at this post http://www.youtube.com/watch?v=cGQn78HANwU

It looks to be identical to my engine but if you look at mine it this one, I am missing the hose coming from the top of the air cleaner and going to the top of the air pump. I have the hole in the bracket and it looks like there is a spot to connect a hose to it too. This might be another reason I have little vaccuum???

You have a main vac line, the large black line with branches off it, between the brake booster and vac pump. That is a different set up than the video. Looks like someone capped the air filter housing off, good.
Measure the vacuum at the first opening (nipple) closest to the pump, plug off the other nipple, what do you have?
Remember, you have Frankenstein under the hood, so it's difficult to make comparisons.

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83 SD

84 CD

Right when I was going to praise Mercedes for being consistent with their cars throughout the years I encounter this damn vaccuum system. I hooked up a mityvac to the main line coming from the air pump and I get a consistent 24. All the lines that are disconnected hold nothing at all. Brown, small yellow, and green w/yellow. The blk line going to. The trans holds a little but also leaks even though the trans shifts. The line to the cruise control holds perfectly also. This is driving me insane. The car shuts off again which is good.