Hose from rollover valve to filler neck: variations?

[Jonathan]

This hose is apparently supposed to be a little wee one like this: http://store.delorean.com/p-6704-hose-roll-vlvfuel.aspx

Mine, as it turns out, is much longer. Say, 12 inches and it loops down a little and then back up to give itself space to not kink. The parts manual hardcopy I have references a hose change and refers to one of them as 108743. This part is not found on the current webstore though.

Did the hose length/style change at some point? Any issues with having a longer one (assuming it isn't cracked or split or full of bug nests)?

[DMCMW Dave]

I've seen both, no idea about VIN placement. The only problem I've ever seen with that is that the hose can get kinked when someone gets sloppy about the placement. This can cause the tank to pressurize and leak fumes or even wet gas.

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PS the short ones have been known to crack and leak fumes. That's really all there is to look for.

PPS The rollover valve (Hi Matt) has been known to get stuck and cause the tank to pressurize as well.

[Jonathan]

Here's a couple pics:

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I had the rollover valve removed when I took these, but you can see where it would go. The hose from the right side is the one that is usually short, but mine isn't (about 18 inches as it turns out). It just does a little loop down and then back up again. The hose connecting from the left side goes down towards the tank and then meets up with the hardline along the frame just in behind the left front wheel.

In the second pic you can see the hose has gotten dried out some and split at the ends. I didn't see that the cracking had gone beyond the hose clamp, so I'm not convinced this is where the fuel fumes were coming from. The hose has been replaced though anyway, so we'll see once it's all back together and I get the car out again.

[FABombjoy]

I'm doing a hose refresh on my car as well. On my '82 I have the short hose and not the long (not surprising).

The braided hose that runs to the canister was cracking just as above. The little non-braided formed hose was perfect, flexible, no splits, no signs of deterioration whatsoever.

[Jonathan]

I'm doing a hose refresh on my car as well. On my '82 I have the short hose and not the long (not surprising).

The braided hose that runs to the canister was cracking just as above. The little non-braided formed hose was perfect, flexible, no splits, no signs of deterioration whatsoever.

Yea, weird how that type of hose tends to fall apart like that. I found a replacement pretty easily for the short one, but haven't yet found one for the longer one that goes to the canister. If I had to guess (I haven't removed it yet) that canister hose that goes from the rollover valve down and around to meet up with the hardline at the frame, would be 3 feet long? More maybe? You happen to remember how long yours was? The routing gets a little busy under there and it'd be nice to have at least a little extra slack to get it out of the way of other hoses or things and neatly tucked away against an edge somewhere under there.

[FABombjoy]

If I had to guess (I haven't removed it yet) that canister hose that goes from the rollover valve down and around to meet up with the hardline at the frame, would be 3 feet long? More maybe?
I ended up buying 3 feet of 1/4" evap hose from the local auto parts store. The factory hose seemed longer than it needed to be and I may have only used 2 feet, even with proper kink-free routing (around the brake booster so it doesn't contact the steering shaft).

I replaced the brake booster vacuum line at the same time and found it was splitting at one end. Since you're in the neighborhood I'd change that one out, too.

Be sure to use actual vacuum hose or a stout reinforced hose for the booster. IIRC it's 3/8" and a hose that isn't rated for vacuum may collapse when hot. Advance initially wanted to sell me fuel hose which would have gone soft under heat & vacuum.

[Jonathan]

I ended up buying 3 feet of 1/4" evap hose from the local auto parts store. The factory hose seemed longer than it needed to be and I may have only used 2 feet, even with proper kink-free routing (around the brake booster so it doesn't contact the steering shaft).

I replaced the brake booster vacuum line at the same time and found it was splitting at one end. Since you're in the neighborhood I'd change that one out, too.

Be sure to use actual vacuum hose or a stout reinforced hose for the booster. IIRC it's 3/8" and a hose that isn't rated for vacuum may collapse when hot. Advance initially wanted to sell me fuel hose which would have gone soft under heat & vacuum.

Thanks. That hose I replaced came in a package of 2 feet. I shortened that one, but could easily get another to use for the hose going to the canister. I'll have a closer look at the booster hose while in there too. Thanks for the tip!

[Jonathan]

Anyone with some tips or advice on how to get a new hose onto the metal hardline when its going to be a snug fit? Can I put a small dab of gear oil or something on there for lube? Any do's or don't's? It's a goofy place to reach and I'm trying not to damage the hose or hardline with trying to force it on. Thx.

[FABombjoy]

Cram a small deep-well socket into the end of the hose to stretch it a bit, then warm it with a heat gun / hair dryer.

[novadmc]

Anyone with some tips or advice on how to get a new hose onto the metal hardline when its going to be a snug fit? Can I put a small dab of gear oil or something on there for lube? Any do's or don't's? It's a goofy place to reach and I'm trying not to damage the hose or hardline with trying to force it on. Thx.

i replaced mine recently. i just used a drop or 2 of silicone spray on the metal hardline then slid it on. same for the replacement rollover valve. just a drop on the tip and it slid right no (phrasing?)

[content22207_2]

Be sure to use actual vacuum hose or a stout reinforced hose for the booster. IIRC it's 3/8" and a hose that isn't rated for vacuum may collapse when hot. Advance initially wanted to sell me fuel hose which would have gone soft under heat & vacuum.

The guys at Advance were correct. Fuel line hose has a reinforcing braid that typical vacuum hose lacks. It's also multi layered whereas vacuum hose typically is single layer. Holds up excellently to not only to vacuum, but to years and years of use in a hot engine compartment. I've used fuel line hose as vacuum hose for a quarter century now (fuel line vacuum hoses on my Brown pickup truck date from the 1990's).

(Recently changed the brake booster on the Brown Truck for the first time since the 1990's -- fuel line vacuum hose was in perfect condition so I left it in place:

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I supply fuel line hose for vacuum lines with my carb conversions specifically because it is superior hose for that application.

Bill Robertson
#5939

[FABombjoy]

The guys at Advance were correct.
If you were here and could have inspected the fuel line -vs- the line I ended up with (trans cooler) I think you would have agreed the fuel line wasn't as suited for the task. I'm sure there are some variations among brands but the fuel line I was presented with was much easier to pinch closed.

I've measured upwards of 24in/hg vacuum in datalogs and have had issues with standard hose collapsing in vacuum applications before. I am also going to be adding an additional check valve right off of the intake manifold to the booster lines which means the hose leading to the booster will see sustained periods of high vacuum.

[content22207_2]

I fully agree transmission cooler hose is heavier duty than fuel line hose -- transmission cooler hose connecting auxiliary air tanks on my service truck:

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But you didn't say in Post #6 that transmission cooler hose was heavier duty than fuel line hose -- you said that fuel line hose itself was unsuitable as vacuum hose, which is totally incorrect. Fuel line hose is imminently suitable as vacuum hose. It also comes in more sizes than transmission cooler hose (3/16" for example -- automatic transmission modulator valve, spark advance, etc).

Bill Robertson
#5939

[FABombjoy]

you said that fuel line hose itself was unsuitable as vacuum hose, which is totally incorrect.
I said that the fuel hose they wanted to sell me would have gone soft, whatever particular brand it may have been. I'm sure there are a million fuel hoses that would have worked but the cheap option was made out of bread crumbs and beaver spit.

The moral was that if you're going to utilize a product for something other than it's declared purpose, consider its suitability for said new purpose. Since I could pinch it shut with my thumb and forefinger with little effort, I had no doubt that approx 10-12lbs per sq/in would do the same over the 2 feet necessary to connect it to the hard line.

[content22207_2]

Autozone's fuel line hose is Made in USA (transmission cooler hose is too). It is very suitable as vacuum hose.

Bill Robertson
#5939

[content22207_2]

Autozone sells two different brands of fuel line hose: Goodyear and Armormark. Both are Made in USA.

3/16 Armormark fuel line hose going to a MAP sensor:

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Bill Robertson
#5939