I learned something about fuel hoses today. Did you know....?

[69hurstolds]

Did you know that on factory supplied fuel hoses from the hard lines going through the front crossmember on the passenger side of a 1985 442 that they used 1/4" and 3/8" fuel lines that were PRE-FORMED???

I did not realize this until today. I just assumed they were regular straight hoses just curled up to fit on the nipples. I wrestled off the A.I.R. pump and A/C compressor today and laid bare the factory-original fuel hoses going to the fuel pump. The 1/4" fuel return line and the 3/8" supply line are actually pre-formed hoses with a near 90 degree bend where they meet the pump nipples. I thought initially they just ended up that way over the years, but under closer inspection, they actually were made that way.

Now, this sucks, but I do have the capability of bending the new fuel hoses to mimic what the originals were done. I have a set of tiny spring copper tube benders that you can slide into place inside the hose, bend it how you want it, steam it in place and it holds its new shape. The little spring acts like a mandrel which keeps the hose from kinking as it's bent. Similar to how some exhaust pipes are bent.

When I get a round tuit, I'll come back and show you how I did it. I've done this before when I had to replace a gas tank hose on top of a fuel tank and it worked out ok. You know, those squirrely hoses that bend around for no apparent reason?

 

[SS_Malibu]

I was gonna send you one of my Round Tuits but this was all I could find.

 

[69hurstolds]

I was gonna send you one of my Round Tuits but this was all I could find.

Good. That means I have more time. 🙂

 

[69hurstolds]

Here's what the crusty old OEM fuel pump and hoses look like. You can see that the ends of the hoses are pre-bent. And the return line also has another little hitch in its giddyup about 2/3 the way down.

THIS is what happens to your sh*t when you park it in the back of the shop for oh, say 20 years.

The lower section of the fuel inlet hose is simply arched with no pre-formed bends. But the 1/4" return line does have one more little pre-formed bend down there. Very odd.

 

[383_StealthRam]

I'm sure you probably already know this, or have done your own research as well.

You'll want to use SAE J30 R9 hose which is much better resistant to ethanol blended pump gas (E10/E5) as opposed to what would be exact replacement for what was used back in the 80's without the ethanol.

I only mention it because in a local parts store, if you ask for some standard gas hose they might just give you the cheap stuff off the roll on the shelf. In the past I've always had to ask for the better (sometimes called fuel injection) hose specifically, even if I was using it on a low fuel pressure, carbureted car.

Love reading your "learning" posts, they're always super interesting, and packed with great information. 👍

 

[69hurstolds]

I'm sure you probably already know this, or have done your own research as well.

You'll want to use SAE J30 R9 hose which is much better resistant to ethanol blended pump gas (E10/E5) as opposed to what would be exact replacement for what was used back in the 80's without the ethanol.

I only mention it because in a local parts store, if you ask for some standard gas hose they might just give you the cheap stuff off the roll on the shelf. In the past I've always had to ask for the better (sometimes called fuel injection) hose specifically, even if I was using it on a low fuel pressure, carbureted car.

Love reading your "learning" posts, they're always super interesting, and packed with great information. 👍

Thanks for the tips. Actually, I did exactly that in the Gates "barricade" hoses rated R14. I think the 1/4" vent line may be R9, but can't recall. At any rate, no more R7 for me. I considered R7 for a second because we do happen to have no-ethanol gas available here. But lately they've run out more often than I'd like, so I reconsidered. Plus, if I were anywhere else, I may not be able to get no-ethanol. So yeah, all my hoses are at least barricade hoses rated for 50 psi. A bit pricier, but hella better on alcohol permeability issues.

But when I get done with them, they'll look like OEM style so one would never know. Even going to change out the ones to barricade hoses on top of the fuel tank.

The bigger issue I think will come with the fuel pump. I have a new Delphi pump that's SUPPOSED to be more compatible with E-gas, but it has that funky stupid shape to it where it bolts to the block. Not sure I want to do that. I have several NOS Delco 442 pumps, but then, these are regular NBR diaphragms (R7 rated) but they are the "correct" pump. Since you can hardly see it when the A/C compressor and A.I.R. pump is in place, I may still use it. Ball's in the air on this choice yet. Must think about it.

 

[86LK]

I'm sure you probably already know this, or have done your own research as well.

You'll want to use SAE J30 R9 hose which is much better resistant to ethanol blended pump gas (E10/E5) as opposed to what would be exact replacement for what was used back in the 80's without the ethanol.

I only mention it because in a local parts store, if you ask for some standard gas hose they might just give you the cheap stuff off the roll on the shelf. In the past I've always had to ask for the better (sometimes called fuel injection) hose specifically, even if I was using it on a low fuel pressure, carbureted car.

Love reading your "learning" posts, they're always super interesting, and packed with great information. 👍

I don't think the FI hose is any more resistant to ethanol-gas than regular hose. pretty sure you need to special order the right type of hose with rubber compound

 

[383_StealthRam]

But when I get done with them, they'll look like OEM style so one would never know. Even going to change out the ones to barricade hoses on top of the fuel tank.

Those ones on the top of the fuel tank have that curly q S-shaped mold to them too from the factory iirc? When I recently replaced my in tank EFI Walbro pump (that lasted 10+ yrs btw) with a Racetronix, I upgraded them to the R9 low permeation stuff, from the R7. I just made the gradual curves and used the original rubber hose separation block and foil taped it all in place. It worked out good, and looking at the pic where I added the harness loom as an abrasion sleeve it made me think about those lines up front from frame to fuel pump on the 307 engines.

Didn't one or both of them come from factory with the split polyvinyl harness loom over top? Maybe wasn't on the Olds models but I worked for Cadillac in 80's/90's and maybe I'm remembering it from the big Fleetwood Broughams that used the 307(Y) in that period. I'm guessing just for some additional abrasion protection from the engine moving in it's mounts over time.

Sounds like you have a solid plan. Wish we had the option of non ethanol fuel around here, I'm sure there are a few places but few and far between.

 

[69hurstolds]

I don't think the FI hose is any more resistant to ethanol-gas than regular hose. pretty sure you need to special order the right type of hose with rubber compound

It typically is. This is a BASIC and generalized chart below of fuel lines. FI hose is generally R9 but stiff as a board. Working pressure for R14 is the same as the cheap R6/R7 stuff (R7 came on your G-body from the factory) but the permeability is like 50 times less. Problem is, you have to look up the standards themselves to determine the specs.

R9 specs:

• Maximum Fuel Permeation: 15g/m²/day
• Temperature Range: -34°C to +135°C
• Working Pressure: max 100 PSI

R7 Specs:

• Maximum Fuel Permeation: 550g/m²/day
• Temperature Range: -34°C to +125°C
• Working Pressure: max 50 PSI

These are excerpts straight out of the SAE J30 (2022) latest version.

The Permeation g/m2/day is the column to check for the fuel soak resistance. None of them are huge by themselves, but R14 actually has a longer time period for the 15 number than the R9.

When it comes to "our sh*t" on regular engines for the daily stuff most of us do, R7 is the least desireable, even though most hose companies say it can handle E10 (I'm not taking any chances), but R9 and R14 are no slouches. If you run a carb, get NON-FI hose R14 and you'll be able to run nearly any pump gas you want. R9 for FI cars because of the higher working pressure. You're stupid if you use non-FI hose on an FI system. Although the R14 T1 is rated at 100 deg C (T2 at 125, same as R7 original hoses), who da fuq gonna boil your dam fuel anyway? Unless something stupid happens, that R14 gonna last.

 

[86LK]

did a quick lookup on the stuff we sell at Advance, nothing better than 30R7. take a closer look at the actual product when I get back in the store tomorrow