I seem to have a problem with the vacuum system. Probably just a leak or disconnected hoses (I hope).
Its an 85 300TD wagon.

I see many of the rubber tees and 4-way and 3-way splitters seem old and cracking, most of anything rubber that is connected to the vacuum system looks like its crady to crumble but just maintaining a seal as long as it doenst get a tug.

My trans started shifting heavy, power locks never did work since we bought the car but I didnt care much for that, however Im thinking, would this all be related to one possible problem with the vacuum system?

From reading through other posts It sounds like it could be. Ive tried looking for the rubber tee replacements but can't seem to find them or dont know what they are called.
I guess Im really wondering, is it possible to pinpoint where the vacuum leakage or problem is without doing any major mechanical work (i.e. removing major parts to access a hose or connection to check)?

Attached are two pics the one on the left is of the line I found that goes to the transmission. I dont know for how long or how it got disconnected but I cant seem to find an obvious place for it.

I tried sticking it in a 4-way rubber attachement but there were two orifices open without any hose in them so it didnt seem like it would make any difference as air would escape throught the other one anywyas.

If you can zoom in or see closely I put it in the orifice thats right beside the small transparent filter (picture on the left) where theres a little rubber orifice looking toward the camera. And I plugged the other hole with a screw. nothing seemed to change though. Transmission is still shifting heavy.

Ive looked over some of the diagrams offered on the forums, still a little confusing to me though. I can never tell if its the same set up as mine.

Any thoughts on this issue. Or pictures of how the lines should be placed under the hood on this model?

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Hi
Its best to replace the old vacuum connectors and rubber hose. The 3 & 4 way connectors are less that $3 each at ******** Az. Vacuum hose can be bought at any auto parts store. Fastlane is also good and helps support the forum.

Diesel Giant.com had a nice pictorial on DIY vacuum system troubleshooting. You will need a hand vacuum pump/tester. Harbor Freight.com has the MityVac at a good price

When you start replacing things do only one thing at a time as its very easy to get lost and not remember where things were. Golf tees are very handy as temporary hose plugs.

Good Luck,

Joseph

A mity vac is a must for these cars. just block off each section to narrow down where the leak is from.

the green lines are for the climate control.

the brown line in for the fuel shutoff

the yellow lines are for the door actuators and the vac tank above the fuel tank in the trunk. that tank is a reserve for the door locks, fuel door and trunk only.
there is a yellow check valve at the firewall, one line goes to the vac tank and the other goes to the drivers door.
Lift the drivers floor matt there will be yellow lines running to the various doors.

yellow-red stripe, lock.
yellow-green stripe, unlock.

Looking at the vac diagrams at the top, looks like the black transmission line connects to the blue flying suacer. shows a green check thingy it connects to.

Charlie

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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

Thanks Charlie, I have a mity vac that Ive used for fluids, (fuel lines mostly). will it work just as well for vacuum lines? there is a pressure guage on it.

Yes.

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83 SD

84 CD

Yes in the picture it looks like it would connect to something in that area as thats where the line naturally springs to but the only hole I could find open are the ones on the 4 way rubber connector

Does anyone know off hand if the transmission (Modulator?) should be air tight? When i connect the mityvac to the hose that leads directly to the transmission and it dosnt quite hold a vacuum when negative pressure is applied.
I made sure the rubber connector that goes to the transmission was good and the actual line is also good.
Any help would be greatly appreciated, This is looking like a big job to find where the leak(s) are.

Yes, I believe the modulator should hold a vacuum.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Hmmm. So is there any way I can find out where the leak is coming from within the modulator? Is this the part that is connected directly tot he transmission?
I see theres a rubber cap close to the valve piece that connects to the hose that runs up into the engine. Would this have anything to do with it?

Heres a few Pics that I'm hoping will give some Ideas to help diagnose some problems. Its an 85 300TD wagon.

Picture 1: There is a small part attached to the firewall that has an open end and I don't know what its for or if it matters. Any Ideas?

Picture 2 Somethings fishy with this piece. The hose thats sticking straight up with the green thing is capped off. Seems pointless to have the green thing there if its caped off. Could there be a good reason for this. What is this part and its function?

Picture 3 is a side view of a cluster of lines. Does this filter serve a purpose? Practically every line I test shows a leak somewhere. However Te hard plastic lines themselves seem to be standing up to the test.

Im wondering if there are any suggestion procedures to narrow down possibilities in finding a leak i.e. most likely place to look first then less likely places later?

Also where should the hose from the transmission line be attached? Looks confusing on some of the diagrams.

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85's are a bit different, yet I'll try. Not familiar with TD's either.
#1 appears to be the turbo over boost protection switchover valve, that top end should be connected to the manifold. Where does the bottom line go to?
#2 the green thing is a damper, the blue disc is an '85 (and TD?) item, not sure what it does, or where it should go.
#3 some folks will install one of those as an indication of a failing item, (to catch oil) such as the vac pump or the shut off actuator. Most leaks are the rubber connectors.

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83 SD

84 CD

The Bottom one goes to the part, that I think you can adjust the turbo with?? You can see the line and where it leads to if you look at the pictures in the first post in this thread. The picture called "vacuum General" you can see the dirty/transparent whitish thicker vacuum line coming out from near the firewall at the centre top of the photo and leading to the squarish part with a small screw in the middle.

The unhooked line coming from the blue flying saucer (vacuum amplifier?) should connect to a device on the firewall behind and slightly to the left of the brake booster. On my 85TD that line comes from the device on the firewall, goes around the right of the brake booster, makes a sweeping turn and comes up to hook into that unhooked line with the green canister in it.

I believe I see the line it should be hooked to in your picture number one. There are two vacuum lines in that picture behind the booster connecting to a device on the firewall to the left of the booster. One of those lines, should connect to the unhooked line on the vacuum amplifier.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Could the device close to the brake booster be the one pictured in the post today at 5:09 pm containing 3 pictures in it? (it would be the first picture with the red arrow pointing toward it.)

And just to be sure, is the brake booster the big black round metal part that says "Girling" on it?

Yes that is the booster but no it does not go to the device with the red arrow, it goes to the device to the left of that. It's the line pictured in Picture 1 traveling left over the brake booster. Trace back the two lines above the brake booster and you should find one disconnected somewhere.

'Left' in automotive parlance(from the driver's point of view), not as in the left of the picture.

If your car is like mine, it's disconnected just downstream of the blue vacuum amplifer inside a vinyl sheath which covers a group of vacuum lines.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13