97 Buick LeSabre vacuum lines

[rawheight]

Hi guys,

My 97 LeSabre threw a check engine light the other evening while I was letting it warm up after work. Code was a P0171 which led me to look at the vacuum lines. The lines look ok but the fittings are all cracked and dry rotting, definitely need replaced like yesterday. Went to AutoZone to get new fittings, but they didn't have any like the old ones on the shelf. Asked the guy up front, and it turns out they don't have anything at all for the vacuum system on a 97 LeSabre. He pointed me toward the GM dealership in town, but it turns out all the parts for the vacuum system on that car are discontinued.

Anybody run into this issue and have a work-around or know where I can find the right fittings?? I really don't want to have to re-design the whole vacuum line system if I don't have to. In the meantime, some high-temp RTV seems to have fixed the problem temporarily.

 

[-Regal-]

I replaced the line in the second image you showed on my Pontiac with a Series II 3800. Simply used a similarly sized piece of hose. If the whole fitting comes off with the line for the other two you show, doing the same work as well. Have made vacuum line repairs on my Cadillac doing the same thing; its cruise control now works because I added a bit of hose where the old plastic line stretched.

 

[GliderRides]

Looking at the third pic ... Think I would see if a piece of fuel hose would fit on the engine side, then slide the hard line past the swage (bulge) in the hard line and clamp it. Guessing on the size, 5/16 vac hose might do it instead of fuel line.

Could do something similar on the 90° piece, but would take a smaller hose, like a large vacuum hose. May need clamps or small zipties to make it fit tight.

There oughta be a law .... If something worked for 75 years, don't change it to some bastardized design that accomplishes the same task, then dump it all in 10 years.

You might end up re-plumbing it anyway, those hard lines tend to become brittle and may break when you start working with them.

 

[-Regal-]

I never needed a clamp or ziptie but it might not be a bad idea.

 

[rawheight]

@Regal LTD Coupe I'm not as worried about replacing the lines, that will be simple enough, as the connectors. Most of them are connecting one size hose with a different size nipple. It's just going to mean buying a lot of different connectors and a lot of different hose diameters if I can't find the original fittings somewhere.

@GliderRides you're right... I was hoping GM would have a whole vacuum system kit I could buy with hoses already built up. Since it sounds like I'm probably just going to have to build them myself, is it ok to replace the vacuum hoses with something more flexible than that hard plastic? What temperature do they have to withstand?

 

[-Regal-]

Those fittings/connectors I wouldn't worry about. Remove them and stick the hose directly onto the metal line. They would actually be in the way anyways if you're trying to use a rubber hose rather than a plastic factory line. Also, you might find some factory fittings in better shape at a junk yard. Keep in mind this Series II 3800 motor was common to many GM vehicles and used until 2005 so I'm a bit surprised the dealer wouldn't have them.

 

[rawheight]

@Regal LTD Coupe How important is the diameter of the vacuum lines? I noticed there were two different sizes of lines used, and most of them connect to a larger diameter nipple on the components. It'd be nice to be able to replace them all with just one size hose, but I don't know how that would affect the engine.

I was really annoyed when I found out GM didn't have the connectors. I was even more surprised, though, to find out the parts stores don't have any aftermarket connectors either, for such a popular engine.

 

[GliderRides]

I never needed a clamp or ziptie but it might not be a bad idea.

Depends on how snug it ends up being. A clamp or ziptie won't work if the hose fits too loose, but if it's just a bit loose, it works. With one that's too loose, the clamp will just pucker the hose and it will still leak.

 

[GliderRides]

You can use regular rubber vacuum hose for the replacement of the hard line. The trick is getting the replacement hose to connect with the larger nipple at the manifold or component. In some cases I have 'sleeved' a smaller hose into a larger hose, then clamp/ziptie gently.

Might find something on ebay, I've been surprised quite a few times.

 

[Merkava_4]

1997 Buick Lesabre CUSTOM 4DR VAPOR CANISTER & RELATED PARTS-V6 3.8K

I'm posting this drawing just for reference.

 

[-Regal-]

@Regal LTD Coupe How important is the diameter of the vacuum lines? I noticed there were two different sizes of lines used, and most of them connect to a larger diameter nipple on the components. It'd be nice to be able to replace them all with just one size hose, but I don't know how that would affect the engine.

I was really annoyed when I found out GM didn't have the connectors. I was even more surprised, though, to find out the parts stores don't have any aftermarket connectors either, for such a popular engine.

I wouldn't be concerned about the diameter of the line, as long as it all fits.

 

[carlos&carlos]

I replaced them last year. I just went to Auto Zone and bought this vacuum line. It worked fine.

 

[rawheight]

@Merkava_4 that's the same image I got from the GM manufacturer... Unfortunately with the words "discontinued" next to all the connectors.


Thanks for the help, guys! Looks like I will just be jerryrigging a new system.

 

[-Regal-]

It's hardly "jerryrigging" .. the dealership or any mechanic you brought it to would be doing the same thing lol. But again check junk yards if you want to retain the factory setup.

 

[Merkava_4]

Replacing the plastic tubing with vacuum hose is the easy part. Being able to connect the new vacuum hose to the individual components is the hard part. You're going to need vacuum connectors and vacuum adapters. Dorman is the only company I know of that makes them. The vacuum adapters allow you to step up or step down in hose diameters. I'm just not sure if Dorman is going to have everything you need.

 

[bfaling]

I gather that these vacuum lines are a high failure item for this vintage Buick?

I got the same DTC on my LeSabre of the same year. Live data suggest a vacuum leak but I hadn't started looking for leaks yet.

 

[2007LucerneCXL]

Any 24 year old vehicle will have components rubber, plastic or metal that depending on mileage and driving environment will need replacement, especially exposed to chemicals and engine bay heat.

Just get some bulk hoses in various sizes and replace them. On replacement one at a time and on any connected to plastic cut them off as pulling my brake the plastic.

 

[-Regal-]

I gather that these vacuum lines are a high failure item for this vintage Buick?

I got the same DTC on my LeSabre of the same year. Live data suggest a vacuum leak but I hadn't started looking for leaks yet.

I think it's likely that A vacuum line could go on a 20 year old 3800 motor, not necessarily the one in question.

 

[Mad_Coachman]

Something like this would help for the double lines coming out of the throttle body.

More Information for GM GENUINE 24507476

 

[bfaling]

Any 24 year old vehicle will have components rubber, plastic or metal that depending on mileage and driving environment will need replacement, especially exposed to chemicals and engine bay heat.

Just get some bulk hoses in various sizes and replace them. On replacement one at a time and on any connected to plastic cut them off as pulling my brake the plastic.

I found the culprit. The line that goes from (roughly) the intake manifold to the vacuum actuator in the front of the transaxle case came undone at the actuator. I plugged it back in and, cleared the code and fuel trims immediately corrected. All of the vacuum lines, surprisingly, were in excellent condition, as were their fittings. The line that came loose didn't rest naturally over the transaxle actuator's nipple; it's a semi-rigid line and it overshot it by a centimeter or so, causing it to tend to pull off in the outboard direction.

Why this was the case is unknown but the upper and lower intake manifold gaskets were recently replaced with new OEM gaskets and I'm guessing that changed the lay of that line slightly. I'm trying to think of a way to lay that such that it points directly down to the nipple instead of trying to tug on it like it does now.