I replaced my rubber fuel lines - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**IT Cowboy** · 01-26-2026, 06:41 PM

Today I replace the rubber fuel lines. The old ones were getting pretty crusty and were about a hot summer or few good bumps from giving out. I loosened the rear line under the cab from the tank to the steel line and it started to leak as soon as I loosened the clamp. I think it was worn where the clamp and home met the bulge on the line. I put the rounded edge clamps on everything and I should be good to go for a while.

**WorldsCrappiestTruck** · 01-26-2026, 08:15 PM

Great work bud - an ounce of prevention…..

**IT Cowboy** · 01-26-2026, 08:21 PM

Quote:

Originally Posted by WorldsCrappiestTruck

Great work bud - an ounce of prevention…..

I keep a fire extinguisher in the truck JIC

**mike16** · 01-27-2026, 12:09 PM

My experience is that they ought to be replaced every 4 years. Current fuels seem to cause some fuel lines to harden considerably even within that 4 year window.

**MikeB** · 01-27-2026, 03:43 PM

Did you notice the rating on your old and new hoses?

Here's the lowdown on types of fuel hose:

SAE 30R6 and 30R7 Hoses
These hoses were the industry standards for decades. SAE 30R6 and 30R7 hoses were designed for fuel systems rated at 50 PSI or less of working pressure like carburetors and TBI fuel injection. The hoses have a nitrile rubber inner liner reinforced with single-ply braided cord and a neoprene rubber cover. SAE 30R6 and 30R7 hose is not compatible with ethanol and many modern additives designed to boost gasoline octane.

SAE 30R9 Fuel Injection Hose
As the name implies, SAE 30R9 hose is designed for use with EFI systems that use hose clamps and have working pressures of 100 PSI and up. It features a fluoroelastomer inner liner that can handle all types of fuel including oxidized gasoline, diesel, methanol, and ethanol-blend fuels. SAE 30R9 hose also resists fuel permeation so it’s emissions-legal.

Replacing old fuel hose with SAE 30R9 fuel injection hose is the smart play. The small price difference compared to SAE 30R6 or 30R7 nitrile hose is well worth it.

01-26-2026, 06:41 PM	#1
IT Cowboy Senior Member Join Date: Jan 2025 Location: Arizona in a van down by the river Posts: 618	I replaced my rubber fuel lines Today I replace the rubber fuel lines. The old ones were getting pretty crusty and were about a hot summer or few good bumps from giving out. I loosened the rear line under the cab from the tank to the steel line and it started to leak as soon as I loosened the clamp. I think it was worn where the clamp and home met the bulge on the line. I put the rounded edge clamps on everything and I should be good to go for a while. __________________ 1972 C10 Custom Deluxe Highlander 402 Freedom isn't safe, it requires you to take responsibility for your own life, your own safety, and your own success. It carries with it the possibility of failure and the understanding that you're working without out a safety net. If you give the state the responsibility for any of these you also give up the freedom that accompanies the responsibility.

01-26-2026, 08:15 PM	#2
WorldsCrappiestTruck Senior Member Join Date: Mar 2022 Location: Hinesburg Vermont Posts: 350	Re: I replaced my rubber fuel lines Great work bud - an ounce of prevention…..

01-27-2026, 12:09 PM	#4
mike16 Senior Member Join Date: Dec 2009 Location: bisbee, arizona Posts: 1,609	Re: I replaced my rubber fuel lines My experience is that they ought to be replaced every 4 years. Current fuels seem to cause some fuel lines to harden considerably even within that 4 year window.

01-27-2026, 03:43 PM	#5
MikeB Senior Member Join Date: Jul 2000 Location: North Texas Posts: 4,036	Re: I replaced my rubber fuel lines Did you notice the rating on your old and new hoses? Here's the lowdown on types of fuel hose: SAE 30R6 and 30R7 Hoses These hoses were the industry standards for decades. SAE 30R6 and 30R7 hoses were designed for fuel systems rated at 50 PSI or less of working pressure like carburetors and TBI fuel injection. The hoses have a nitrile rubber inner liner reinforced with single-ply braided cord and a neoprene rubber cover. SAE 30R6 and 30R7 hose is not compatible with ethanol and many modern additives designed to boost gasoline octane. SAE 30R9 Fuel Injection Hose As the name implies, SAE 30R9 hose is designed for use with EFI systems that use hose clamps and have working pressures of 100 PSI and up. It features a fluoroelastomer inner liner that can handle all types of fuel including oxidized gasoline, diesel, methanol, and ethanol-blend fuels. SAE 30R9 hose also resists fuel permeation so it’s emissions-legal. Replacing old fuel hose with SAE 30R9 fuel injection hose is the smart play. The small price difference compared to SAE 30R6 or 30R7 nitrile hose is well worth it. __________________ Mike 1969 Custom/10 LWB -- owned for 37 years. 350/TH350, 3.08 posi, recent AAW wiring harness, 5-lug conversion, 1985 spindles and brakes. Hedman stainless headers. Old Air installation in progress. 1982 Custom Deluxe 10 SWB -- converted from 250-six to roller cam 350 w/ Vortec heads -- sold 1981 C10 Silverado LWB, 305, TH350C -- sold, but wish I still had it! 1969 C10 (not the current one) which I bought in the early 1980s. Paid $1200; sold for $1500 a few years later. Just a hint at the appreciation that was coming. Retired as a factory automation products salesman. Worked part-time over the years for an engine builder and a classic car repair shop. Member here for 26 years! This is the very first car/truck Internet forum I joined. I still used a dial-up modem back then!



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