FAQ: Vacuum Hoses & Lines (Series II SC)

Hi everybody, i just purchased a 96 riviera, the old owner did´nt want to spend more money because it ran REALLY bad.

So me beeing a total newbie when it comes to cars newer than 1975 decided to see if i could find the problem, and i think i did.

The problem is a vacuum coupler that connects the throttle body with the supercharger and a vacum canister (see below) its totally messed up and rather than trying to just kinda get it to work with couplers and hoses etc id like to find the original.

see the picture below, the large ends goes into the throttle body, the small end goes to the supercharger (the plastic line that you see on the pics is the one commning from the supercharger, it seems broken since it should be way longer to fit the coupling) and the medium sized goes to a metal line that conects to some kind of a canister.

So does anybody know what parts im looking for, were to find em and/or if i should just use hoses and a 3 sized vacuum coupler?

I would REALLY apreciate some help!

ive had to replace almost all of my vacuum lines. and will probably need to again before its all said and done.
next time I will use SILICONE hoses only. They withstand the heat better.

that being said, I just went to an autoparts store and bought generic replacement hose. Vacuum leaks are rampant on this car and cause alot of problems due to it being a forced induction engine.

Agreed on using regular vacuum hose.

If you go with silicone, get premium stuff that you probably can't buy at the parts store. I've tried the cheap stuff, and that's what I got.. cheap stuff.

you can not find that T fitting on the 96's at the auto store! it is dealer only b/c one of the ends is made smaller than the others. mine cracked on me and it messes up all kinds of stuff since the 96s trannys are vac controlled.
i can see if i can find the part # for you, but it comes as a small set in a bag for like $10.

Oki, i followed your advice, got some couplers and a couple of different sized vacum hoses.

Went ahead and change the thermostat to a 180, change the old sparkplugs (went with the 605´s), changed oil and filter (got rid of old black tar and the crappy fram filter, replaced with mobil 1 and a mobil 1 filter), changed the sparkplug wires and finally sealed a couple of other vacuum leaks.

Holly sh*t, it went from a car that ran like a sack of crap to a car that would outperform my old 69 mustang (with a stock 351 4v) in a heartbeat.

Happy!

Thanks

Mr.Riviera wrote:

you can not find that T fitting on the 96's at the auto store! it is dealer only b/c one of the ends is made smaller than the others. mine cracked on me and it messes up all kinds of stuff since the 96s trannys are vac controlled.
i can see if i can find the part # for you, but it comes as a small set in a bag for like $10.

Oh, if you could that would be great, even tho it works now i´d rather go with a stock one.

nice job!

part # 24503990 for the vac line pack
and part # 24503881 for the harness
i cant remember which one had the T but they cost me 15.00 for both back in 2005.
it was a special vintage order item too.

Thanks alot, next time im around a delaership ill place an order.
Im beyond pleased with this car!

Nice to have a fun daily driver to complement my fun car (78 trans am with a lt1 engine, aluminum heads, 4 wheel dics etc etc)

mobcharge wrote:

Oki, i followed your advice, got some couplers and a couple of different sized vacum hoses.

Went ahead and change the thermostat to a 180, change the old sparkplugs (went with the 605´s), changed oil and filter (got rid of old black tar and the crappy fram filter, replaced with mobil 1 and a mobil 1 filter), changed the sparkplug wires and finally sealed a couple of other vacuum leaks.

Holly sh*t, it went from a car that ran like a sack of crap to a car that would outperform my old 69 mustang (with a stock 351 4v) in a heartbeat.

Happy!

Thanks

Awesome! Congrats for getting a great deal and a fun car!

Thanks, i have one more question tho..

Were is the PCV valve located?

Remove the engine cover if equipped. Then looking at the throttle body end of the supercharger, there is a black plate on top of the SC about 4 inches away from the TB and about 2-3 inches away from the large vacuum distribution on top of the charger. Under that little plate is the PCV.



Flat black plate with two bolts up and to the left of the vacuum distribution.

Ok so i replaced a few vacuum lines that i broke when replacing my boost bypass valve and am not sure if i routed them correctly...car is running fine just not looking right for some reason.. Can anyone post some pictures of the vacuum routing on a 96? thanks!

will that do, or do you need another angle?

If you could get one from the other side of that it would be great ... Thanks!

other side of the BBV or other side or the engine? there is only 1 line running the back side of the engine, and it goes around up under the snout of the blower.

Ok i see what im missing now... Thanks again.

When you open the PCV, be careful the spring doesn't pop out. it can shoot quite a distance!

Yeah...now you tell me... I found that out the hardway....good thing theres some wiring that got in the way.

Mr.Riviera wrote:

other side of the BBV or other side or the engine? there is only 1 line running the back side of the engine, and it goes around up under the snout of the blower.


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lol, did you break the nipple off the end of the BBV and had to rig it too?

looks like some southern engineering there.

that was one of the first things i had to fix when i got this car, and it has held for 5 years.
it may not look pretty, but it works

No but i did break the T-fitting for the at the throttle body that connects to transmission... I Called a dealer and they searched and told me the part was discontinued. So i had to rig that into place...I'll post pics up later in case anyone else goes through the same thing... Also since i fixed the valve it seems to have regained some boost.( losing traction in upper rpms now in first...although that could have something to do with the cold as well.

A few days ago, my boost gauge started jumping from 10 vac to 20 vac, there was no in between.. and when i got up around 7-8 psi, it would start jumping around like it was on some crazy illegal substance.. I finally popped the hood and the rubber Tee I was using was totally destroyed and cracked. I found another one at autozone, (the same exact one) but I don't want to have to keep replacing them (not that it's hard or expensive, I just want one that will last more then 4k miles..) Can anyone reccomend a quality vacuum T fitting, and some quality vacuum hose to replace the plastic crap that came with the gauge?

Do you know the specs on the T? OD, or what hose ID fits? It's possible I could come up with something in steel.

why does it keep breaking would be my first question. there should be no stress on the T fitting unless it is rubbing against something. you are talking about the one on the rear of the blower housing that connects below the snout?