Vacuum issues 1984 300TD

[dkarten]

I have vacuum at brake booster line but no engine shut off, door locks or CC, I have kick panels out & have removed instrument panel, trying to learn how to use my vacuum bleeder gauge to find leak, not sure how to proceed & welcome any suggestions

[meltedpanda]

I suspect a door valve or vacuum tank issue . This may help,

vacuum gauge has to be used at each point to see if valve is faulty or other component
Could be as simple as a disconnected line

[dkarten]

Thx for reply, I believe the yellow/black stripe hose that goes to vacuum tank in rear is the issue, can I access that connection without removing vacuum tank?

[dkarten]

Correction, yellow with grey stripe

[dkarten]

I see now the yellow/grey hose goes into the tank under wagon floor, panel over the vacuum tank to give access, nuts are rusty so I sprayed with Kroil will remove tonight,

[tyl604]

Wonder if this could be two problems - 1) engine shutoff and 2) locks. If the engine does not shut off, it could be the shutoff valve which is located in the back of the injection pump. In my 81 300SD I had this problem and a new shutoff valve solved it. Will take a look at an old post to see if the directions are still there.

See: 1981 300SD No shutoff - how do I find vac leak? There is a pic in post #11 and good instructions in the thread about how to replace it.

Good luck.

[meltedpanda]

vacuum leaks can be pesky , and why I said you almost have to check each connection . Systematically eliminate some lines - you will figure it out !

[dkarten]

I disconnected the yellow/grey hose to the vacuum tank at both ends & tried pulling vacuum, nothing, so I plugged the port at the check valve where that hose connects & now engine shuts off with key, so that yellow/grey hose that goes direct to tank & must have break in hose somewhere

[meltedpanda]

sounds good, nice work!