Evap leak repair: 98 V70 with VIN emissions code 7

[S Carlson]

New baby, new code: P0442 rises to the surface during parental leave. Now, while he's sleeping, let me tell you about it.

Our 1998 V70 T5 (FWD NOT AWD) has given me whiffs of fuel vapor for some time now. Recently we've gotten the P0442 small evap leak code. N.B. I DID redo the sealant around the fuel pump wires, as I know that fails. Fuel cap is also newish, with good seal. So I went and stuck my hands in the little access hole for the pump and for the level sender, thinking OK I'll do the well-known laparoscopic hose repair. Right off, it is apparent my top of tank hose layout is different from the one in the thread. I can feel a hard, slightly-ribbed plastic hose snaking over the top of the tank. So I go look up the fuel tank diagrams on the online Volvo parts catalogs. I see there are several options, so I check my emissions code digit in the VIN. Mine is 7. So here's the diagram of that (fuel tank and connecting parts, emissions code A, D, J, 7):


The hard plastic ribbed hose I can feel is number 34 in the diagram. The only rubber hose to speak of seems to be number 6, which is Volvo part number 9179420. From other forums, it looks like this is 7.5mm ID fuel injection hose. Kind of a weird size, and a weird spot, but what do I know? All the other hoses are hard plastic or nylon, which would seem less vulnerable to degradation.

Here are two more pictures I dredged up from the internet, of what I think is another tank from a car with emissions code 7. Note the ribbed hard plastic hose I could feel through the pump hole, and the general similarity to the parts diagram.

Volvo_Gas Tank 002.JPG (63.98 KiB) Viewed 2240 times

Volvo_Gas Tank 003.JPG (55.64 KiB) Viewed 2240 times

Note the (very short) section of rubber hose clamped with two Oetiker clamps, just below the three wires coming from the evap pressure sensor. And again everything else appears to be hard plastic, which seems less vulnerable to degradation.

Before I drop the tank to look at the suspect hose, has anyone else dealt with this? Any other ideas of where I should look? Again, this is not the tank like the old 850 with that rubber hose that you can get it by drilling holes in the floor. And I already did re-fill the sealant in the little well around the fuel pump wires and fuel cap seals well. Think I should just go for it with some suitably rated J30R14 5/16" fuel injection hose? Should I also do the filler neck gasket while I'm in there (part 6842188)? It is an expensive little sucker and there is a some rust on my fuel filler neck clamps (part 3531428) so together that's a lot of money if it's not the thing that's leaking. But seems I could leave the neck on and just drop tank to do this hose if I don't see a leak there? Anyone else solve an evap leak on a car with emissions code 7?

[scot850]

Sorry no. I have a friend who has a 98 V70 NA with an EVAP leak. I have swapped out most of the system but all that is left is above the tank, so the tank will need dropped to check up there. I'm confident a mouse may have done a bit of chewing when the car was in storage for a few years. I had hoped to check from above, but it has a metal cover (I have never seen one fitted with that). I'm thinking someone had bumped the tank at some time as I cannot remove that cap (it is under the one on the floor).

I'm hoping you might get to it quicker than me. I am not looking forward to dropping a 28 year old plastic fuel tank!

Neil.

[abscate]

The tank drop inthe fwd cars is pretty easy of you run the volume down to a few gallons. It’s light and easily handled.

The hardware is all top quality stuff, if you have a problem up top it’s probably rodent damage.

[S Carlson]

With daycare closed and a heat wave this week, I have accomplished a total nothingburger of work, aside from cleaning one cowl drain and checking my sunroof drains due to a flooded left front footwell.

Also, stupid amazon has delayed my stupid 5/16 fuel hose. It is hard to get out of the apartment with a newborn, and nearest autozone is in the next town, hence ordering a car thing from jeff bezos

But in lieu of actual progress, here's a picture of my toddler "driving" the V70. Note his focus on the two most important instruments for Massachusetts driving: radio and horn.

[matthew1]

[S Carlson]

Yesterday I dropped the tank. I was somewhat shocked, however, to see that the hose I had long suspected looked pretty darn good! It was still pliable and springy. Any wetness in the picture is due to soapy water, which I'll get to talking about later.

Not quite knowing what to do, I thought back to a thread on this site, in which someone lightly pressurized their tank with a bicycle pump

It turns out this is not a bad idea. The Schrader chuck on the pump fits right on the return nipple of the fuel pump, which goes directly into the tank!

It took me a bit to figure out that the vent valve is of course open when the car is off, so the air was just getting pushed out. I stuck a socket extension in the J-hose to plug it up and tried again.

This time, I heard a hissing! From... the charcoal vapor canister?! Soap bubbles applied everywhere and:

The canister is cracked. So much for dropping the tank
I did check everywhere else top-of-tank with the soap bubbles. I estimate I didn't put much more than 0.5psi into the tank, because the tank is so huge and the bike pump is so small. Certainly no pressure registering on the gauge. But absolutely no bubbles anywhere top-of-tank, especially not at the hose, which I really soaped up and examined very carefully.

So, I reassembled. Dropping the tank was pretty easy. Putting it back up, not so. Before the work, I had run the car until the gas idiot light was on. Even with the tank thusly lightened, it still took me over an hour of fiddling with jacks, bricks, and pieces of wood to get the straps on. First, I put extra long bolts up there to hold the tank straps sorta close, then jiggled and thumped the bottom of the tank to fiddle it into its nook in the bottom of the car. At that point I was able to get the left (diagonal-ish) strap on. The center/right strap that goes pretty much fore-aft on the bottom of the tank was MUCH harder. I ended up with my socket wrench in the cup of my jack, with another jack under the tank, and basically jacking up the socket wrench/extension/bolt assembly until I had engaged it in the hole and then tightening it. Scratched up my wrench a bit, but at that point I was pretty desperate/my wife was mad I was taking so much more time than I had estimated. Then I drove the car to a gas station for a couple gallons.

Aftermath:
1. I bought a replacement charcoal vapor canister. I will install it at some point. I think the original cracked due to the metal retaining piece on the canister bracket rusting, flaking, and expanding against a plastic seam on the canister, which popped open the seam.
2. I didn't even change the little hose, because there were absolutely no bubbles coming out from it or anything else on top of tank, and it felt nice and pliable, and I was running out of time. If I do end up needing to change it, I will probably cut a largeish squareish hole in the back subfloor above-ish it. I will put in some rivnuts (nutserts?) so that a panel hatch can be bolted on top. It's not worth dropping the tank - or more precisely, it's not worth putting it back up, to fix that. Plus, then I can look at it in-situ with the tank full and really evaluate for seepage.
3. "while I was in there" I changed the two half-shell metal clamps that hold the filler neck onto the tank. Mine were original and very rusty. I had been worried about a sudden failure and spilling out half a tank of gas. Unfortunately, the new ones (Skandix from FCP) didn't really hold the thing tight, even when they are fully bolted together. The filler can "wobble" around relative to the tank, whereas it could not previously do so with the original severely rusty clamps. I believe my original ones had expanded/flaked due to rust and crushed the mushroom-shaped rubber gasket. Rust flake expansion is a powerful force! Rusty rebar can crack concrete, so why couldn't it crush a gasket, I guess. I will have to replace this as well, but for now am not filling the tank above half because I don't want to find out if my old one still seals. It's too bad, as that gasket is $50. Anybody have thoughts on this clamp situation?

I will keep you posted, as it appears I am not done yet...

[S Carlson]

OK so, I got a chance to do a bit more work.

First off, I replaced the charcoal vapor canister.

A word about parts: This car and a number of other late P80 and early P2 cars use the canister part number 30684417. It is ridiculously expensive from any source I can find except used. Heck, even used, if you want exact part numbers, it is crazy priced. An alternative is 30684418, which is exactly the same part, except that the nipple for the J-hose is a quick-connect instead of a barb. I got one from ebay for $20. I think it is OES, quality appeared quite good and featured ground-off part number underneath a foil decal. I don't think oem quality matters much here, it's a simple part and won't result in the car stranding me anywhere.

It was not super difficult to remove the vapor canister. First, I removed the hoses. The rubber J-hose comes off when unclamped. The two others are quick-connect. The small one took a lot of wiggling while squeezing the quick release tab, and a bit of penetrating oil to get it to budge. The big one requires a retaining clip to be slid out, but then it was easy to remove with a little twisting and gentle tugging. Then, I loosened the vapor canister in its cage. The little Torx bolt that holds the retaining washer for the vapor canister was completely rusted fused solid. I half-heartedly tried a Torx socket in it but it stripped immediately. I would not use heat due to the presence of fuel vapor and plastics. I took a cold chisel and hammered at it until the head broke off, then grabbed the retaining plate/washer and twisted/wrestled it out of the slot in the vapor canister cage. Then I wiggled the canister loose from the cage, as rust was holding it fast.

I unbolted the two bolts that hold the muffler bracket and left side of the vapor canister cage, didn't touch the one bolt between the cage and fuel filter strap, as this was fused solid and would have required cutting it off. The left side of the cage dropped down and I was able to slip the canister out and slip the new one in. Then just re-bolted it back up and all was good!

I used a stainless steel m6x20mm hex bolt and nut and two large stainless washers to retain the new canister, in place of the hopelessly rusted Torx bolt and retaining plate. If you didn't want to use a bolt, zip ties would definitely suffice.

My canister had developed a big crack right along the bottom, where the little bolt and washer retain it in its cage.

Made in murica GM quality
What I want to know is, why did my Volvo come with a GM part? I thought GM only cast their cursed shadow over Saab? But GM follows me & keeps turning up like a bad penny.

See, the 30684418 and 30684417 are the same except for the nipple. I just hose-clamped onto the nipple with a nice Esska stainless hose clamp. Future upgrade may be to grab a quick-connect hose from a junkyard car and quasi-eliminate the troublesome J-hose entirely! The 30684418 even seems to have thicker plastic on the edges, which may help with future cracking (although shouldn't crack with stainless hardware!).

I reconnected the canister hoses and moved on to my next thing: the loosy-goosy filler neck gasket.

The gasket, as I mentioned, seems to have been compressed by a rusty/flaky filler clamp. After putting the new clamp on, the neck could move freely with respect to the tank. I was betting on a leak. I took the clamp half-shells back off and cut a circular shim out of a plastic oil bottle to put on the tank-side inside the clamp. This made things acceptably tight. I went to the gas station and put in $55 of sweet unleaded hormuz juice, filling to the brim. I so far don't smell anything, and I don't see any seeps! I am now waiting for the drive cycle to complete in order to see if the code is gone! Fingers crossed, I am hopeful.

Edit: Attachments fixed, thanks Matthew!

[matthew1]

S Carlson, from the forum software upgrade last night to about 30 minutes ago when I fixed it, attachments didn't land, they went into the ether and are not recoverable. Can you upload again? Or email them to me and I'll edit your post [email protected]. Apologies.