How many (miles of vacuum hose) must a man walk down?

Oh, boy. I knew there was some spaghetti under the hood of this car, but until I did some research into the actual components connected to that string-theory of an engine I didn't really know.

To be inexact, the Oldsmobile, 307 cubic-inch, electronically carbureted (sounds stupid when you say it) engine has 25 or more feet of hose (of various sizes) under the hood. That's an estimate based on the amount I've used to replace some of the most cracked and worn hose plus a guesstimate of the remaining hoses. It's a lot. And they're not in friendly places to reach, either.

I wanted to get into this because a) the car is 28 years old and, shit, something probably leaks somewhere, b) I don't know what's already been done by the previous owner, c) it's disgusting ugly under there, d) there were some interesting things going on with the idle and stalling after the engine had been stopped and started hot, then finally e) I wanted to understand the how and why all the hose was there in the first place. Y'know, really understand the vacuum diagram posted on the radiator cowl and what each component is and does. This new learning will help when I have to take it all off later trying to replace head gaskets, intake manifolds, and valve covers later....

Also, side note: I was quoted by a professional restoration shop for body work and repainting of everything. Top to bottom, rust repair, refinish, clear coat; the works. $15,000. The very awesome dude said (and I paraphrase here), "I wouldn't recommend doing all that though. I would focus on the major trouble spots that will cost you down the line." These 'trouble spots', as he called them, included the roof, hood, and the bumper filler on the rear quarter. The recommended option was to keep as much original as possible to retain value on the vehicle for future sale. I agree, but not for the value reason. Simply because they quoted only $3000 for that work.

Anyway, the dialogue between me and this engine compartment begins. I'll try to include photos of the process below. Safety not guaranteed. I have only done this once before.

Oh, boy. This is under the hood of a 1989 Buick LeSabre Estate Wagon. "Can we fix it?" NOPE.

To elaborate, this is the sticker vacuum diagram for my particular version of the Olds 307. It's... not to scale... or comprehensible unless you know what to look for. 

Here's the version I printed out online: Fig. Fig. 45: 1988-90 Olds 307 At least I can see it without moving to the front of the car every time to check, but damn.

First things first, take of the air cleaner assembly. Pretty much every job on this engine requires this step because it's in the way of everything. And I mean everything.

There's a hose on the driver side that comes from the crankcase breather element. 

A second large hose is on the passenger side. 

Finally, there are two small hoses. One is connected to the cleaner itself, but the other attaches to a vacuum port.

Just disconnect it carefully. There's a sensor inside the air cleaner that the hoses connect to and they didn't look serviceable. Try to twist the rubber back and forth while tugging gently. You don't want to break either the hose or the plastic nipple (a major PITA). 

Et voilà, the carb is exposed along with all those rubbery, hosery goods.

To start, let's look at what each component looks like on this diagram. Shit damn, there's a lot of 'em. This is the CAN on the front passenger side, right up against the front grille and radiator support. I assume it stands for canister, but I'm not even sure. One hose disappears under the vehicle toward the gas tank vent. Following the other leads us to the next part of the map.

Sadly, I don't have a picture of this behemoth junction of hose. This is the "CCV valve" or crankcase ventilation valve. It's pretty easy to follow the hoses that connect to this though. To help, the largest hose coming from it is the one with the "TBV valve" (throttling butterfly valve valve) inline and connects to a port on the upper front of the carb. You can see the nipple in the next photo at the top right corner.

This photo has a lot going on in it. The TBV valve line terminates at the nipple in the upper right corner. 

This is better. The orange plastic joiner connects everything from one hose on the CCV. One goes directly to the carb, the thin one goes to the wiring harness, and the other...

...connects to a component hiding under the oil fill cap. 

There's actually two hoses going to this device. I believe this is the "CAN purge solenoid" on the diagram.

There you are, you cute bastard. "The purge valve precisely controls the amount of fuel vapor that is purged from the charcoal canister." So the CAN is the charcoal canister. Such knowledge!

Anyway, back to the hoses at hand. Here you can see the large hose disconnected from the carb (with the rusted clamp) and its nipple in the upper middle.

Again, the vacuum diagram for reference. We're shifting gears (car puns!) to the other side of the vehicle.

This fucking thing is the "SOL ASM" which I believe to be the solenoid assembly. Or something. Anyway, there's about one hundred and eleventy hoses coming from it (going to it?). These all looked to be in pretty good shape. I think it's because they're far enough away from the heat of the engine and fuel vapors to be fairly stable, as far as rubber goes. I didn't end up replacing any of these.

From the SOL ASM it's easy to find the "EGR" valve, aka, exhaust gas recirculation valve. 

Here it is now. This is important, from what I've researched elsewhere online. Since the carb is controlled electronically and it's calculating the fuel/air mixture based on these gases being added in, removing this thing causes weirdness, but you can do it. I prefer to keep everything the way papa GM intended, however. I've also heard that this engine, particularly tuned for these emissions devices, runs better with it. Good news though! If you lose yours or need a new one (since they can clog up and die, causing shitty performance), there's plenty of aftermarket and OEM valves available.

This is another easy one to find from the SOL ASM. 

The "VRV", or vacuum regulator valve. Pretty simple inline connection.

It leads to the "VDV", aka vacuum delay valve.

Here's the VDV, I think... It might be the "ANTI-DIESEL SOL". The VDV could be the small bits on the left side of this photo, the junctions that come out and connect to this piece.

Anyway, the whole thing goes to this "VAC TANK", which is easy to find.

Just following these hoses.

To this ball-shaped object on the passenger side. The pair of hoses are coupled together with rubber straps and routed across the front of the engine. What asshole designed this?

Now it's time to get down and replacin' the most broken, flaky of hoses. I didn't do all of them obviously, but there were some pretty easy ones to spot that had cracks around the fittings or were flaking rubber from vibration and age. These were my weapons of choice for the old hoses.

My shopping list. I needed a 1" wrench and a 5/8" flare wrench for the fuel filter inlet (more to come on that shit show later). These are all inner diameters. Papa O'Reilly had everything I needed.

For clarity, you should start with maybe 4' of 7/64" hose (really small). I think I only used maybe a foot so far. 10' of 5/32" (the most common hose in this beast). To do the whole vehicle it might not be an exaggeration to buy 20'. 8' of 7/32", the second most common hose. Might go up to 10 or 12' on this one to be safe and have enough. Finally, 4' of 3/8" fuel hose, which I mostly used on the CAN (giggity).

All these are cheap, like, between 50¢ and 99¢ per foot. The 3/8" hose was fuel hose, and that was much more expensive at $2/foot.

So I started here from the VAC TANK. There's a short length of hose and then it connects to this other line for some damn reason. I don't know if this was done at the factory or if someone else worked on it. Anyway, I kept the coupler in there just so it seemed to relieve stress on the hose from the tank.

Follow the same line all the way in front of the engine. You might notice that it goes to two places.

The larger diameter hose terminates at this point in front of the carb. I think this is "MAN VAC" on the diagram.

The other goes to this, the suspect ANTI-DIESEL SOL.

Since the hoses were paired with the rubber band straps, I cheated and used silicone lube to squeak them off and back onto the new pair I put together. Sort of a pain, but it looked nice once everything fit. Nevermind the hammer. The scissors worked for cutting the new hoses to length.

Now that's done, this hose on the CAN was looking really shabby and I think it's because it's a fuel vapor line that rubber hates, so it deteriorates quickly. This is the 3/8" fuel hose I needed. For god's sake, don't tug like a maniac at these fittings. They're plastic and probably older than you are. Use a razor and cut a slit on the old hose, then pry it off around the edge with a screwdriver.

The 3/8" hose terminates at the CCV on the diagram. 

Remember to take off and reuse the metal pinch clamps on the new hose.

I'm not sure what this other ball-tank is right above the CAN.

It leads to a T-junction near the front passenger side of the carb.

Not sure what this thing is, either. (edit: It's part of the AIR pump/smog system and comes from the AIR pump) I'm only messing with them because their rubber hoses looked less than great.

Ignore where the screwdriver is pointing. The unknown (edit again: AIR pump) thing has two hoses from it.

One goes back behind the A/C compressor. (edit: behind the a/c being the actual AIR pump)

I tried to get a photo of it, but shit's hard, man.

This one was really easy. Like three inches of  7/32" hose, right in front of the carb near the TBV. 

Following this hose from the CCV.

Goes to that mysterious device under the oil fill cap on the passenger side (there are two hoses there, choose the passenger side).

Better light? Worse light? Ahhh, who cares...

Finally, this top small diameter hose from the CCV was replaced.  A short distance to the junction connector (the orange plastic thing I'm pointing at).

That was pretty much it for replacing the hoses for me. I was happy to leave it at that and fix just the ones visibly cracked and rotten. If the engine gives me trouble I'll do a proper vacuum leak check and diagnose any of those valves/hoses that I looked at. 

For some reason, there didn't seem to be any resource online for how to route those hoses or what each component looked like on the diagram. Hopefully this is helpful to someone searching for info on this smog-choked engine.

Next time: Remember that fuel filter I threw shade on? Also: Oxygen sensors and you! Stay tuned.