Need Help - Melting Fuel line

[Burbman]

Thought I would toss out the issue and see if anybody can tell me what's going on.

Car is my daughter's 2001 Grand Prix with 3.8L V6. Replaced the intake manifold gasket and had a leak develop at the fitting on the fuel rail shortly thereafter. Dorman makes a repair kit that uses a brass barb to splice into the nylon fuel line and has a new fuel rail connector on the other end. This is the part:



Basically you just warm the nylon so that it will go over the fitting barbs and when it cools its sealed. Made this repair the first time last summer and a few weeks later the line started to drip at the splice. Not on the OEM side but on the new Dorman side. The new nylon line softened up to where it wouldn't hold the seal on the brass barb anymore.

So I figured the part was defective and replaced it again. Drove it about a month and no leaks. Double checked it, no worries and daughter took the car back to school with her after Thanksgiving.

Two weeks ago I get a panicked call that fuel is running from under the hood like a faucet. She lost 1/2 tank of gas going 6 blocks to the mechanic's garage. Diagnosis was that the same Dorman line was leaking again. Mechanic replaced it, all good to go. They use a Napa nylon fuel line repair kit.

Two days ago I get another, same thing, except now car won't start at all. So it gets towed back to the garage, same line leaking again. Mechanic was great, the didn't charge her for the tow or the repair.

I call down there today to see what's up and to suggest that maybe they put a hose clamp on that barbed fitting. Mechanic says the clamp wouldn't have helped because the line melted! So they replaced it and off she goes with instructions to come back tomorrow so they can check it.

In total that make 3 failed fuel line repairs on this car, all seeming to give out due to a softening of the nylon. The fuel pump and filter are new, we don't run any additives in the gas....what could be causing these failures? Aside from the inconvenience, I'm concerned the car is gonna catch fire and it will be toast before the firemen ever get the truck out of the garage....

Sh'e not running E85, just plain ol' regular from Kroger.

Ideas?

[dsmuts]

I'd just use some rubber fuel injection line.

[DarkPassNger]

If the line melted ...My guess is ... it got close to the exhaust manifold of the engine. I would get something to secure it to make sure it does not come in contact with the manifold if indeed that's what melted it...even tie wraps would work I would think.

[nd48463]

Glad to see I am not the only one! I damaged the same fitting when I did my intake gaskets. That was 3 months ago. Friday on my way to work I started smelling gas. I had just filled up so i thought nothing of it until i pulled up to a stop light and smoke started rolling from under the hood!! I immediately pulled over and turned the car off. I popped the hood and saw fuel dripping form the splice. I turned the ignition to the on position and saw fuel spraying out directly onto the exhaust manifold!! Luckily it did not catch fire! I looked at the dorman repair line and it was as soft as jelly and looked like it grew in size. Luckily I was a block away from the hardware store so I grabbed a bunch of hose clamps and that was good enough to get me home. I since have just bought a piece of hose and put that on. Unbelievable that dorman would offer such a piece of crap product that could easily cause fires under the hood.

[BillBoost37]

I did a dorman repair kit, but didn't have much luck with it sealing to the barb on the new side. This left me heading to the store for some injection hose and double clamps at both ends. Never had an issue.

While this all looks good and seems great, we definately are putting these splices right above exhaust. A moment ago in a thread Scotty was talking about 120F intake temps. Engine bay temps get very hot and definately right above exhaust. I do the super deluxe braided lines with all parts that will never give out. It's costly, but like you mention.. lighting a car on fire.... Another thing that can be done is to take fuel injection hose and go down by the firewall or just under the car and use double clamps and hose all the way to the rail. That hose is rated for the temp and pressure.

[Burbman]

UPDATE

The last fix seems to be holding. This nylon repair is very common and every repair shop has a full kit with the requires parts and tools. They use what is essentially a modified bar clamp to press the fittings into the line. Still amazes me that the engineer who designed this would rely solely on the nylon line to form an effective seal on the fitting, especially when fuel is involved, and especially when right over the exhaust manifold. Probably the same guy at GM who spec'd that ignition switch.....

The mechanic I spoke with said they had a bad batch of nylon line...they bought a new reel of it and so far no problems, but every line they made with the old reel has this same issue with swelling and leaking. If there was a bad batch of fuel line coming from the mfr, it's possible Dorman got some and made a bunch of faulty repair kits without knowing it.

At any rate the new repair is holding exactly like it is supposed to per specs. We went to visit our daughter last month and line was dry as could be. I showed her where the splice was and told her to check it every time she buys gas. Takes 2 seconds to pop the hood and stick your finger in the split loom and see if it's wet. Also told her that if it doesn't kick over immediately in the morning, that's a sign of leakdown in fuel pressure overnight, another warning sign.

At any rate glad to know I wasn't the only one having this issue.

Bill was that 3/8" line? Assume I can just slice the nylon off and use the same plastic fitting at the fuel rail but with rubber line? I may do that when she's back up here next month.

[BillBoost37]

Supply is 3/8 and return is 5/16.

Another thought.. how about slitting some regular hose an putting it over the line like the loom GM puts over the lines at the factory? Call it a insulating barrier

[Burbman]

Bill you're thinking of this the wrong way....it's not a heat melt it's a chemical melt. When I say "melting", I mean the line is getting soft and gelatinous as a result of the contact with the fuel, not the heat from the exhaust manifold. When the line softens it loses its grip on the fitting barbs and starts to leak. That's what made me question fuel that my daughter was buying but nothing new there. Like the bad batch of line was missing an ingredient that made it impervious to degradation from fuel.

Actually where the fuel and return lines are run in 1/2" split loom and those are combined in a giant 1 1/2" spli loom, the mechanic got rid of the outer one on the basis that it serves to disguise the leak. As the nylon softens and begins to lose its grip, the leak starts slowly as a drip. If you can catch the leak while it is dripping you can repair it before it gets too dangerous. the layers of split loom hide the initial drip so the first sign of it leaking is when the line gets soft enough to start spraying fuel.

[Turbocharged400sbc]

if the OEM fitting Orings are leaking I take the dorman kits apart and swap the Orings and spacer rings over....far easier.

aside from that the OEM plastic gets replaced with braided rubber or ptfe hose around here....

[BillBoost37]

Hey.. I only thought heat, because.. well..there's heat present and people were also talking exhaust manifolds.

[Burbman]

Had the car back this week and inspected the fuel line repair. No leaks, but the new line was still "softer" to the squeeze than the OEM nylon line. I had a small hose clamp and decided to use it on the new part of the line at the brass splice fitting as a safety measure. Tightened the clamp and........pssssssssss........fuel dripping. Not sure why adding a clamp would cause the line to leak, but , nothing surprises me about the ol' GP anymore....

So up to Advance for some 3/8 reinforced fuel injection hose and FI hose clamps (no slots in the bands). Sliced the nylon off of the fittings and installed the hose with double clamps at both ends. Hose was a little looser on the barbs than I would have like but held tight with the clamps. No leaks, and hopefully I am done worrying about this. Next stop was a complete new fuel line for a hundred and change at GM parts direct.

I appreciate the advice and assistance from the forum members here.

FWIW, there were no more of these nylon line repair kits on the Dorman rack at Advance....not sure if Dorman stopped making them or Advance stopped carrying. Either way they shouldn't be selling these things unless they can get them to work properly.

[Russosaur]

I never would buy anything from gmpartsdirect the shipping is outrageous. Iv always ordered stuff from the part department at the dealership usually comes in, ina few days

Sent from the Milky Way

[Burbman]

Sorry, you are right, I stopped using those guys too. My main source for parts is Rock Auto. If a part is "dealer only", then I order from GM Parts Giant. Shipping is reasonable and prices are usually about 40% lower than what the dealer charges. You have to wait a few days either way, may as well save some scratch.