2019 Bullitt - Fuel line leak!

[NGOT8R]

I went to the drag strip last Thursday and noticed my car begin to act up, in that it was hard to start, just like it was before I installed the Deatschwerks inline check valve. I made three passes on motor that night and the mph was still on point in the 1/4 @ 116.71. On the drive home I noticed the car was jumpy or like it would mis briefly while holding the throttle steady.

Fast forward to today, I noticed a strong odor of fuel when I cycled the ignition switch (but didn’t start the car). I looked underneath the car on the driver’s side and noticed a small puddle of fuel on the ground. My first thought was that it must be one of the fittings that I crimped onto the fuel line when installing the check valve, so I cycled the ignition again to prime the fuel line, while looking at the check valve and it’s fittings. I saw a mist of fuel and the sound of air as the line pressurized and then depressurized. Further investigation under ample light revealed the leak was coming from the fuel line itself in the area indicated by the red arrow in the photo.

Needless to say, I am perplexed as to how this could even happen, as the work that I did to install the check valve was several inches away from the source of the leak. This got me to thinking back to an anomaly that occurred couple of weeks prior. I noticed that when cycling the ignition switch during priming only, I saw the fuel pressure on my nitrous controller exceed 100 psi. However, once I started the car, the pressure immediately settled to 80.3 psi (which is normal).

Is it possible that the fuel line ruptured due to the excessive pressure that I mentioned during priming only? I only noticed this a couple of times within the last two weeks, when I had the nitrous controller on which shows fuel pressure. I don’t generally keep the controller powered up, so who know’s how many times the pressure has built up that high and gone unnoticed.

I’m still trying to come up with a plan of attack that might allow me to make the repair without having to remove the driveshaft, exhaust and cradle, so that I can lower the fuel tank, SMH. If there’s anyone here that has experienced this issue and can provide insight as to how the repair was approached, I would love to hear from you. Thanks.

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[NGOT8R]

For reference, here is a photo of the DW check valve thatI installed. It’s been on the car for several months now btw. To put things into perspective, the leak is roughly in the area of where the yellow circle is in the bottom right corner of the photo.

 

[NGOT8R]

I cut most of the factory fuel line out using mini bolt cutters. There’s about 12-14 inches left to remove and wouldn’t you know it, it’s the section where the leak is. I hope to be able to finagle it out from in front of the fuel tank and out the bottom of the car.

Once that’s done I’ll order some PTFE line and make my own fuel line. One thing’s for sure, it won’t ever be this difficult to address a fuel line issue in the future, should I ever need to.

 

[NGOT8R]

Got that muthaducka! I had to remove the driver’s side subframe brace, unbolt the driver’s side tank strap (which lowered the tank on that side only) and wiggle the line out from inside the car. It was a bit of a PITA, but at least I was able to do it without dropping the exhaust and driveshaft to get the tank low enough to get the line out.

See yellow arrow in photo which is pointing to the source of the leak. It appears that the nylon portion of the line was fatigued in that spot and with repeated fuel pressure cycles it finally blew a hole in the line.

 

[sms2022]

Not surprising unfortunately. All the wiring and plumbing on this car seems shoved into place and under stress as a result. I’ll have to check mine. I wouldn’t mind running PtFE all the way up to the engine.

 

[SheepDog]

I was thinking maybe you nicked the line on the edge of the opening in the floor when you were installing the Check valve. I know I've donated some flesh and blood to that area when taking pump assemblies in and out, its sharp as shit

 

[NGOT8R]

I was thinking maybe you nicked the line on the edge of the opening in the floor when you were installing the Check valve. I know I've donated some flesh and blood to that area when taking pump assemblies in and out, its sharp as shit

Nope. At first, I thought that it may have been leaking from the clamp on the quick connect fitting or the o-ring inside, but that wasn’t the case.

The area where the blowout occurred was forward of the tank and I couldn’t even reach it with my fingers until I lowered the tank. Weird, but I think I’m out of the weeds on this repair now.

 

[NGOT8R]

Not surprising unfortunately. All the wiring and plumbing on this car seems shoved into place and under stress as a result. I’ll have to check mine. I wouldn’t mind running PtFE all the way up to the engine.

If you look closely at that pic with the hole in the line, you’ll see where the stainless steel line stops (it has a slight flare to keep the nylon line from sliding off). The hole is about 1/4” down from that. I think that during manufacturing, the nylon portion of the line was weakened when it was stretched over the stainless steel line. With multiple pressure cycles of 80-100 psi over time, it finally said: bye, bye.

 

[NGOT8R]

New fuel line and a smaller Deatschwerks -6AN check valve has been installed. I used push-lock fittings with clamps to ensure that the lines don‘t blow off of the fittings.

Specs on fuel line are as follows:

Certified for use with racing fuels, ethanol-based fuels (E85+), diesels/bio-diesels, methanol, and ethanol/gasoline mixtures. This hose will not deteriorate, dry, harden, or permeate fuel (emit fuel vapor) with the presence of ethanol in gasoline. This hose is also ideal for use in crankcase postive pressure ventilation (PCV) and evap lines.

Features and Benefits

• SAE J30 R9 rating for excellent fuel impermeability
• NHRA Approved
• Epichlorohydrin (ECO) rubber outer cover
• Smooth bore Viton® (FKM) fluoroelastomer rubber inner layer
• Reinforced with an embedded aramid fiber braid
• For use with push-lock style fittings (not for use with re-usable "cutter" style or crimp AN hose end fittings)

Application Notes

• This hose should NOT be submerged in fuel or used inside of fuel tanks
• A hose clamp is required when using smooth hose barb fittings. Hose clamps are recommended when using push-lock fittings and required when operating pressure is above 10 psi.

Specifications
Operating temperature range (all sizes):

• -40°F (-40°C) to 300°F (150°C) operating temperature

Vacuum at 20% deflection (all sizes):

• 23.9 in/Hg (810 mbar)

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