FAQ: Vacuum Hoses & Lines (Series II SC)

i know they eventually dry out and crack.
silicone vac lines are supposed to resist heat better. I might use them when I do my intake because most of the vac lines will have to come off anyway and I know I will break a few.

RhinoFLA wrote:

.....the rubber Tee I was using .....

Are you sure it's rubber? Hard plastic maybe? I should be able to find you a hard polypropylene replacement at work, if you want to try one. (on the house)

Sorry for the late reply. No Matt, it's the one near the boost bypass canister. It just looked dried out and some pieces had fallen off.. i'm pretty sure it's rubber, it's quite flexible.



It's the T with the zip tie on it.

I made mine wit a brass fitting and brake lines some work but will work forever.

where do i purchase them??? the dealer told me im nuts pretty much!!!........ but i need the ones that go to the Lower intake manifold and to the throttle body.... just the connectors......... need help ASAP

If you are talking about the "T" fittings by themselves the dealer is right, they are not available from anyone! The only way they sell them is the whole assembly, it is called a Vacuum Harness. It comes with the two "T" fittings and the straight one on one end and the 90* on the other end and all of the lines in between. Around $20 so not too expensive just a pain to get them! The straight and the 90 are available from Advance in their help stuff but not the "T's"

I saw a 1/2" rubber vacuum hose cracked and after I pulled it to replace it, I saw a small 1 inch plastic thing with a hose connector on each end. it has a metal wire mesh inside it. I dont know what direction this connector goes .
A vacuum hose from the top of the engine connects to a metal bent rod [8 inches length] towards the driver side down to near the bottom of the rad into this vacuum connector, connects to a rubber hose and into a large 5 inch round item.
If i had a diagram, it would help me

I have 1996 SC 3800 II Rev

It sounds like the vacuum line to the brake booster. A picture would certainly help...

The round 5” item on the driver’s side is the vacuum modulator on the 4T60E transmission.

I went to Advance Auto Parts to find some new plastic connectors after my vac lines crumbled. For my non-supercharged engine, I purchased a plastic T connector with two 3/8” and one ¼” port, a 3/8” to ¼” plastic adapter for the modulator connection, a ¼” to 3/16” plastic adapter for the fuel rail, two feet of ¼” fuel line for the modulator, one foot of 3/8 fuel line for the throttle body connection, one foot of 3/16 fuel line for the fuel rail connection.

vacuum modulator looks like mine
Which direction is it installed ?
large or small port towards vacuum hose running to top of engine ?

qprint wrote:

vacuum modulator looks like mine
Which direction is it installed ?
large or small port towards vacuum hose running to top of engine ?

The port with notch in it points down in my car. It is connected to a 1" piece
of hose that is connected to the vacuum modulator.

I have searched all over, and can't find the basic Vacuum diagram anywhere. I changed my Super Charger, and now need to figure out the vacuum lines to finish.

Thanks,

Newb - Tony

Looks like that is only a list of parts to purchase. I'm just looking for a pic, or scanned image of the vacuum line routing. Just so I can go start my car back up today.

Thanks again

did you change out the supercharger with another one from a 96 or is i a newer design?
on our 96's we have a different vac tree since we need a line going to the transmission. you will probably have to rig up a new design like tonysmooth did when he swapped out his blower for a P&P.
...maybe he can post of pic of what he did you for?

96Super wrote:

Looks like that is only a list of parts to purchase. I'm just looking for a pic, or scanned image of the vacuum line routing. Just so I can go start my car back up today.

Thanks again

Yeh, I read your post to quickly and thought you needed a diaphram, not a diagram.
Sorry about that. i deleted my response.
If anyone has the Factory Manual for the 1996 it will show the proper hose routing.
I gather there isn't a decal on the radiator support otherwise you wouldn't be asking.

Rickw wrote:

96Super wrote:

Looks like that is only a list of parts to purchase. I'm just looking for a pic, or scanned image of the vacuum line routing. Just so I can go start my car back up today.

Thanks again

Yeh, I read your post to quickly and thought you needed a diaphram, not a diagram.
Sorry about that. i deleted my response.
If anyone has the Factory Manual for the 1996 it will show the proper hose routing.
I gather there isn't a decal on the radiator support otherwise you wouldn't be asking.

I have the manual, but wont be able to look it up til much later tonight. So i should have an answer later on.

Rickw wrote:

96Super wrote:

Looks like that is only a list of parts to purchase. I'm just looking for a pic, or scanned image of the vacuum line routing. Just so I can go start my car back up today.

Thanks again

Yeh, I read your post to quickly and thought you needed a diaphram, not a diagram.
Sorry about that. i deleted my response.
If anyone has the Factory Manual for the 1996 it will show the proper hose routing.
I gather there isn't a decal on the radiator support otherwise you wouldn't be asking.

I'm surprised. There is not even a drive belt diagram

L67 wrote:

Rickw wrote:

96Super wrote:

Looks like that is only a list of parts to purchase. I'm just looking for a pic, or scanned image of the vacuum line routing. Just so I can go start my car back up today.

Thanks again

Yeh, I read your post to quickly and thought you needed a diaphram, not a diagram.
Sorry about that. i deleted my response.
If anyone has the Factory Manual for the 1996 it will show the proper hose routing.
I gather there isn't a decal on the radiator support otherwise you wouldn't be asking.

I have the manual, but wont be able to look it up til much later tonight. So i should have an answer later on.

That would be awesome!! Did you buy the shop manual from the dealer? How much was it? I'll probably buy one since I plan on keeping this for 100k or so

96Super wrote:

I'm surprised. There is not even a drive belt diagram

Again, available in the FSM.
If you plan on keeping the car you might want to look at buying a set of Factory Manuals from EBay used. They come up for sale often.
You can expect prices to be between $30.00 and $50.00.
I bought a set within a week of buying my car and they have been invaluable.

Go to EBay Motors and then look for manuals, IIRC.

It's under Parts and Accessories, then drop down tab to Manuals

Well, I paid a subscription to alldatadiy.com The good news is I have 2 diagrams I need. The bad news is the new S/C did indeed come from a 1999 engine. So... I am now missing the 3-tree of vacuum lines (Manifold Vacuum Source) Do you know how I can get around this? Can I use a "T" type connector and use the extra vacuum from the blank (Dead center of the S/C getting vacuum from the throttle body?

Here is a visual:



or is that is not working:

https://2img.net/h/i19.photobucket.com/albums/b189/ssxt8camaro/SANY0586.jpg

Correction, in the picture above it would be Number 4

Is that diagram from a '99 or '96? My '98 does not look like this. It has a T under the s/c snout and the line from the MAP sensor continues around from there to the F/P regulator to the BBV.