[C2] Beware the rubber fuel line at the sender
03-25-2017, 05:24 PM
#1
Race Director
Thread Starter
Beware the rubber fuel line at the sender
Gents,
I was working under my car today and noticed that the rubber hose connecting the sending unit to the hard line was no longer rubber. It had the consistency of hard plastic and was brittle.
I replaced it with braided stainless to match the rest of my fuel system but thought "Holy **** - I can see that cracking in the near future..."
Something to check. I think over time the gas hardens the rubber. Not sure if it would break - but I am sure it's not supposed be hard as plastic.
I was working under my car today and noticed that the rubber hose connecting the sending unit to the hard line was no longer rubber. It had the consistency of hard plastic and was brittle.
I replaced it with braided stainless to match the rest of my fuel system but thought "Holy **** - I can see that cracking in the near future..."
Something to check. I think over time the gas hardens the rubber. Not sure if it would break - but I am sure it's not supposed be hard as plastic.
03-25-2017, 05:53 PM
#2
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C2 of the Year Finalist - Modified 2020
You dodged a bullet my friend. Many years past I posted about owners getting to know their cars and checking that hose was one of the specific things I mentioned. 
Dennis
Dennis
03-25-2017, 06:34 PM
#3
Great catch and a easy to replace maintenance item, it's amazing how much damage that little hose can cause.
Last edited by tbarb; 03-25-2017 at 06:36 PM.
03-26-2017, 09:15 AM
#5
Le Mans Master
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On our 68RS, I fought a problem with rough running and dying for almost a year until I found the rubber hose between the pickup and the fuel line was hardened and cracked and the pump was sucking air.
No leakage to the ground as the fuel is only present when the pump was trying to suck if out of the tank and small leakage would evaporate quickly as the exhaust temperature flashed it away.
Make sure you use a hose rated for fuel, or it will soften and swell until it starts leaking.
03-26-2017, 09:16 AM
#6
Safety Car
Snake, you may want to confirm what material is used for the inside of the braided metal fuel line. Just because the rubber on those lines is covered in a metal braid doesn't make them immune from the rubber deteriorating. Any line in a fuel system that has rubber should be made to standard SAE J30. That stuff is rated for pressurized service submerged in gasoline and lasts a very long time.
03-26-2017, 10:27 AM
#7
Snake, you may want to confirm what material is used for the inside of the braided metal fuel line. Just because the rubber on those lines is covered in a metal braid doesn't make them immune from the rubber deteriorating. Any line in a fuel system that has rubber should be made to standard SAE J30. That stuff is rated for pressurized service submerged in gasoline and lasts a very long time.
03-26-2017, 10:49 AM
#9
Race Director
Thread Starter
Snake, you may want to confirm what material is used for the inside of the braided metal fuel line. Just because the rubber on those lines is covered in a metal braid doesn't make them immune from the rubber deteriorating. Any line in a fuel system that has rubber should be made to standard SAE J30. That stuff is rated for pressurized service submerged in gasoline and lasts a very long time.
03-31-2017, 12:22 AM
#11
Drifting
I recall reading an article on fuel line hoses. The 10% alcohol in modern fuels attacks many of the older fuel hoses that did fine with pure gasoline.
I think the "best" fuel line hose for alcohol resistance is lined with Teflon, which is generically called something like "PFTE." A little internet research would likely provide the details.
My guess is that any "fuel hose" sold today in an auto parts store would be resistant to alcohol, but if you are not sure, I think the Teflon hose is considered the best for alcohol resistance.
Last edited by GearheadJoe; 03-31-2017 at 12:23 AM. Reason: missing word
03-31-2017, 06:50 AM
#12
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St. Jude Donor '07
On our 68RS, I fought a problem with rough running and dying for almost a year until I found the rubber hose between the pickup and the fuel line was hardened and cracked and the pump was sucking air.
No leakage to the ground as the fuel is only present when the pump was trying to suck if out of the tank and small leakage would evaporate quickly as the exhaust temperature flashed it away.
Make sure you use a hose rated for fuel, or it will soften and swell until it starts leaking.
Bill
03-31-2017, 07:08 AM
#14
Team Owner
Lift not required....this is the culprit and as you can see mine was old, had the wrong hard line clamps (worm screw type) at each end and was missing a positioning clamp near the middle at the marked frame hole...all fixed now... I don't remember if I removed the spare tire tub to get at the hose or not..
I may have removed the tailpipe on that side and nudged the muffler out of the way, don't remember - its been a while...
I may have removed the tailpipe on that side and nudged the muffler out of the way, don't remember - its been a while...
Last edited by Frankie the Fink; 03-31-2017 at 07:11 AM.
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Jims66 (03-31-2017)
03-31-2017, 07:10 AM
#15
Under the rear of the car the hose comes from the bottom of the tank and about 10'' long to the hard line at the right side frame. Easy to get to laying on the ground. If yours is in bad shape I suggest you run the tank almost empty, cut the hose with a drain pan under it to catch what's left in the tank.
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Jims66 (03-31-2017)
03-31-2017, 07:13 AM
#16
Drifting
Thanks for the quick response....... How did you stop fuel from running out during the fix? When I change the rubber piece in the front I simply jacked the car up a bit which stopped the flow.
03-31-2017, 07:14 AM
#17
Drifting
Under the rear of the car the hose comes from the bottom of the tank and about 10'' long to the hard line at the right side frame. Easy to get to laying on the ground. If yours is in bad shape I suggest you run the tank almost empty, cut the hose with a drain pan under it to catch what's left in the tank.
03-31-2017, 07:20 AM
#18
Drifting
ILBMF and Frankie the Fink........, I'm assuming you're both retired since your responses are so early in the morning AND you both live in Florida. I'm "close" to retirement and we're looking to retire in the Jax and/or St. Augustine area (Have a "soon to be" married son living in Jax). 
03-31-2017, 07:21 AM
#19
Team Owner
Work in a ventilated area - wear old clothes and safety glasses; clamp off the old hose high on the fuel sender end with these pliers (everybody has a set for fuel/brake line work -- right?); disconnect the other end at the frame hard line and connect the new hose and clamp on that end...put the new hose clamp on the fuel sender end of the new hose...
Quickly remove the old hose/clamp on the fuel sender end (it may require slicing the hose a bit with a razor) and swap on the new hose with new hose clamp already on it and then tighten the clamp.
If you're quick, and dexterous, you won't spill much fuel.. I lost maybe 2-3 ounces at most...
If you want to lose even less you can tape a piece of a heavy plastic trash bag tightly around your filler cap spout with the gas cap removed. You just created an 'unvented' gas tank temporarily.
Quickly remove the old hose/clamp on the fuel sender end (it may require slicing the hose a bit with a razor) and swap on the new hose with new hose clamp already on it and then tighten the clamp.
If you're quick, and dexterous, you won't spill much fuel.. I lost maybe 2-3 ounces at most...
If you want to lose even less you can tape a piece of a heavy plastic trash bag tightly around your filler cap spout with the gas cap removed. You just created an 'unvented' gas tank temporarily.
Last edited by Frankie the Fink; 03-31-2017 at 07:40 AM.
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Jims66 (03-31-2017)