Absolutely stupid question

[WhoWhat]

What am I looking at with these vacuum schematic drawings? I mean, I get it...I get it...all the parts are labeled, but are these things from a side view? Front?

There are two schematics in the stickies for the 123 - I'm looking at both, and I'm totally lost.

My vacuum system is totally erratic (i.e. locks work some times, car wont' turn off occasionally, heat only works through defrost and only comes on about once every 20 tries). I need to get, at a minimum, regularly working heat - it's getting cold in Michigan!

Have a hand vacuum pump (borrowed from friend - Craftsman), so another weekend learning as I go, I guess!

[94mgm]

Try too look at the function instead of the placement. Start looking for leaks at the brake booster line. Move to the trans modulator line, door lock line, reservoir line, climate control line then shutoff line. At some point you will probably find a leak.

[bbail2x2]

the thing is, its a schematic diagram which means you read it like a blueprint. find the part you know and follow the line until you get to the next junction or part. as I've heard before, think of vacuum as a commodity which is supplied by the pump. If you have a gauge I would hook it up directly to the vacuum pump to see what it pulls. they say about 22 Hg. mine only goes to 15 or so. using your Mityvac connect to different lines until you find where it DOES NOT hold vacuum. remember one goes into the cabin for clean atmosphere so it will be open always. Brown I believe goes to the key for fuel shut off. yellow with green or red stripe is for door locks, etc.
you should be able to hook up to the fuel shutoff pod while the engine is running and when you pull a vacuum it should shut off the engine.

I would guess you have a leak before everything splits to all the various functions since several are not working. hope this helps

[NoSparkNeeded]

This is a schematic diagram. It is not a picture of placement under the hood. It's more like a flowchart, sort of. If you take the schematic and
identify all the parts as you look at them under the hood, the schematic
shows the relationship between the parts. So first find the "real" parts that the schematic represents under the hood and label them with tape or something. Then use the schematic diagram to discern what each part
does, and follow the flow of, vacuum, electricity, water, fuel, whatever.
It's like follow the pathway. I hope this doesn't sound silly as I do this all
by thinking in pictures. I just want to give back to this group. I can do all this stuff, but I don't have a talent for 'splainin stuff.

[WhoWhat]

Originally Posted by NoSparkNeeded

This is a schematic diagram. It is not a picture of placement under the hood. It's more like a flowchart, sort of. If you take the schematic and
identify all the parts as you look at them under the hood, the schematic
shows the relationship between the parts. So first find the "real" parts that the schematic represents under the hood and label them with tape or something. Then use the schematic diagram to discern what each part
does, and follow the flow of, vacuum, electricity, water, fuel, whatever.
It's like follow the pathway. I hope this doesn't sound silly as I do this all
by thinking in pictures. I just want to give back to this group. I can do all this stuff, but I don't have a talent for 'splainin stuff.

No, I'm with you. Thanks. I think I'll figure it out (can't be as hard as some of the other crap that I've fallen into with this car!).

Different question - can I use the hand pump as the vacuum gauge on the vacuum pump on the car? Meaning, if I hook up the hand pump nozzle to the car pump hose, will it pull? Or is the handpump only one-way? Does this make any freaking sense?? It's even confusing ME, and I wrote it!

[bbail2x2]

if you pump a vacuum with the Mityvac or use the vacuum pump on the car, the gauge will register whatever vacuum is present.

[WhoWhat]

Originally Posted by bbail2x2

if you pump a vacuum with the Mityvac or use the vacuum pump on the car, the gauge will register whatever vacuum is present.

Roger that. Thank you sir.

[NoSparkNeeded]

Mity-Vac and hemostats solved every vacuum problem I had. A Hemostat
is a somewhat gentle pair of needle nose pliers, with a lock like vise grips
only softer. Doctors use them for stopping the flow of blood in blood vessels, so if you don't squeeze hard they are gentle on rubber tubing. With those and a Mity-Vac you can "section" off parts in the schematic and test. FYI it's ALWAYS the last section you test that has the problem.