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leaking fuel rail cap fix

83766 Views 67 Replies 22 Participants Last post by  atoman
First time posting,
I have a 2001 Chrysler Town Country with 3.8

For several months now, I've detected a strong smell of gas under the hood. After watching it for a couple of days, I noticed gas dripping out of the cap on the fuel rail. I found a post where someone removed the cap and replaced the internal o-ring with an o-ring from the fuel injectors. (Same size) I did the fix, and it has not leaked since I replaced the o-ring. The best part was I did not have to remove the fuel rail. (A new one is pricey) You will need to go to the auto store and ask for fuel injector o-rings for the van. Mine came in a package of 2 for 2.39 from NAPA.

Thse are the steps I took:

1) Relieve gas pressure from fuel injection rail:
Remove the fuel pump relay and start the van, running it until it dies. (The relay is in the fuse box)

2) disconnect the battery (just being cautious)

3) Move power steering reservoir:
Loosen the bolts for the reservoir , lift it slightly and push it to the side.
(There are 2 accessible bolts on the top, and one nut underneath that you just have to loosen)

4) Remove cap:
Gently pry the cap off, use the bracket for the power steering for leverage.

The pic with the blue o-ring is the original. (notice the erosion on it)

5) Prepare cap:
Remove old o-ring
Bend the tangs back on the cap so it will fit tightly when you re-install it.
Lubricate the o-ring with some fresh oil and put it on the cap.

6) Install cap:
Put cap over the hole making sure it is centered.
Gently tap on the end until it slides back in the hole and is seated properly.

7) Check for leaks:
Re-connect the battery.
Put back the fuel pump relay and start van.
Check for leaks.

8) Put everything back together:
Move power steering reservoir back and tighten bolts.

That's it, it is pretty simple to do as long as you are careful.
Not once did the CEL come on.
This cap is not for a test port, it looks more like a pressure relief port.

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I noticed, a few month ago, some fuel coming from under the fuel pulsation damper. I thought it was the fuel injector being lose from when I replaced the O rings last year, so I tightened it up. Even though it didn't leak, I kept my eye on it. Well today, while checking the fluids, I noticed it started dripping fuel from the same spot. At first I was going to try and replace the O ring as others mentioned here, but decided to just replace the fuel rail. Since I replaced all the O rings on the injectors last year, this should take no time to replace. My advice to those with this problem, just replace the entire fuel rail. Its better then taking a chance of a car fire just to try and save $100. Plus you will have peace of mind that its fixed and you can take that long road trip with out any worries.
The dealer quoted me $185 for the rail. Could someone post where they bought the rail for under $100?
Bought ours from the dealer for $110.
For those who doesn't understand this physical effect.

Early carbureted vehicles equipped with mechanical fuel pumps didn't had that problem. I don't belive it has to do with frequency either.

The problem is the "Ariete Hammer". More widely known to plumbers as "Water Hammer". Earlier homes didn't had that problem either, until electronically controlled water valves started being used on home appliances, then a pressure dampener needed to be added to the plumbing system to prevent leaks everywhere.

In your vehicles, the injectors are the "electronically controlled valves".
Every time an injector closes, your system pressure will increase due to the "Ariete Hammer" effect. Multiply that by the number of injectors, hope you get the idea. The Ariete Hammer effect is the main reason a cold weld or resine fix on pressurized lines doesn't last long. It may work on a fuel tank because it is not pressurized.

Now that you know about this ariete hammer effect, use this knowledge next time you need to "fix" or repair a pressurized gas component.
Well said. I say just replace the darn thing because it can start leaking while your driving and you not even know it. Even if the fuel evaporates, it can still catch fire as a vapor. When ours was leaking the drip was small and I didn't smell any gas. I happen to see it by inspecting the engine for other problems.
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My cap was still leaking. It is really a very slow seeping or wetness on the cap at a very slow pace. I decided to remove it to inspect the o ring. It may be the o ring or the seam under the cap where the clips are. No matter because I epoxied the entire cap in place right down to the rail. As of last week I have no more leak or smell of gas. If my $4 fix holds I am happy. I am not spending $140 or more on a 15 year old van with 212k on it. I know tomorrow I will have my next cheap fix to think about. My experience tells me if I reach 275k miles and the van is 20 years old, I am driving it to the bone yard or having it towed. I am on my 8th van and have been buying some new and some old since 1991. I own 3 of them right now. No matter how much money I spend on new parts the rust ( cancer) will make all those new parts a very bad investment if they are bought near the end of the vans life. Right now my van is in stage 3 cancer so I chose to spend only $4. If I spring a leak again I will post it here and then buy a new rock auto fuel rail maybe. I have been driving for 50 years and it is always the cancer that ends my vehicle's life. I always feel very sad when my engine and tranny are still in great shape but they have been shortchanged by a rusty frame and body. Last year I lost 3 vehicles. My van cracked a rear axle and my dodge shadow dropped a coil spring due to corrosion. Only 130k miles on the shadow but it was over 20 years old. You have to know when to hold um and when to fold um.
I totally understand. I had to make the same decision as you, on our 15 yrs old van. We have some body rust on the outer door panels and rear dog legs. Our van has over 187K now and I decided to give new life to our van by cutting out the rust and welding in new sheet metal. It is time consuming and requires a lot of patients. But, it will all pay off in the long run. The most major repair we've had so far is to replace the torque converter. (Which I'm in the process of doing now.) The inside of our van still looks really good with no rips, tears, cracks or stains. (After raising 5 kids) So for me, it was a no brainier. Mechanically, she should be good for another 100K without any major repairs. had an oil analysis done around 7K ago and the engine is very healthy and wearing below the standard. I do 95% of the maintenance myself, so the cost of repairs are minimal. We do have a second car to drive around if I can't finish the fix on time.
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