leaking fuel rail cap fix

83859 Views 67 Replies 22 Participants Last post by atoman, Jan 14, 2017

blknblu

Discussion Starter · May 19, 2012

3

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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41 - 60 of 68 Posts

wayneh

· #41 · Jan 4, 2015

atoman said:
How thick are the tube walls at the damper? can you tap the opening and put a bolt or cap nut in/on there? (with some thread sealer or epoxy)

No, it's too thin to tap, and the cap does have a function even if the design is stupid. By that I mean the cap seals with an o-ring but cannot reasonably be opened to service the o-ring, without distorting the 4 little tabs enough to permanently destroy a good seal. Actually, this would be OK if you could just buy a replacement cap to replace along with the o-ring.

It would be easy to just remove the cap and plug the hole, but that doesn't seem like a good idea. If I were to do anything along these lines, I would surround the entire cap with epoxy right down to the rail. I picture using an old film container, with the bottom cut off and the plastic sleeve slipped over the cap, as a mold to hold the epoxy while it hardens.

atoman said:
The true ******* way of fixing it would be to put a hose clamp around the rail over the cap

I'm honored. I'm using a cable tie to hold the cap down. I used it to hold the cap in place while my JBWeld hardened, and saw no reason to remove it.

I found a source to get the rail delivered to me by expedited shipping for less than $70, so I ordered it. Fuel tank repair epoxy sounds like a workable solution but the kits cost at least about $10 and I think I'd need 2 of them to have enough material. Add in all the work to clean and prepare the surfaces, and it just seems more practical to replace the rail entirely.

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atoman

· #42 · Jan 4, 2015

wayneh said:
I'm honored. I'm using a cable tie to hold the cap down. I used it to hold the cap in place while my JBWeld hardened, and saw no reason to remove it.

I'm glad you feel honored (vs offended)

What I had in mind was actually (a permanent 'emergency' repair) - such as splitting a length of rubber fuel hose lengthwise and clamping it over the damper opening with a stainless hose clamp..

Hope the new rail solves it for you.

wayneh

· #43 · Jan 15, 2015

Put the new rail in today and all is well! It only took a half hour in the steam room to thaw myself out afterwards.

FWIW, it looks like my JBWeld fix actually held. It was dry under there. The "wetness" was on the injector directly under the hat, but none on the hat or the rail underneath. I don't really know what what was going on but again, all is clean and dry with the new rail installed.

I'm good at it now, but I hope I never see my fuel rail again.

Reactions: 1

itsallgood

· #44 · Sep 10, 2015

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.

morggab

· #45 · Feb 4, 2016

The dealer quoted me $185 for the rail. Could someone post where they bought the rail for under $100?

blknblu

Discussion Starter · #46 · Feb 4, 2016

If you do it carefully, replacing the o-ring will work. When my van was sold (late last year) it was still holding.
The trick is to make sure the prongs are bent back to where they are supposed to be.

georgef

· #47 · Feb 4, 2016

morggab said:
The dealer quoted me $185 for the rail. Could someone post where they bought the rail for under $100?

Part number 4861498AB or 4861498AC for 2001 thru 2002 is available from Rockauto for $75 plus shipping.

Part number 4861498AD for 2003 thru 2007 is available from Rockauto for $113 plus shipping.

You can find a 5% off discount code here: RockAuto Introduction & Discount Code!

morggab

· #48 · Feb 4, 2016

blknblu said:
If you do it carefully, replacing the o-ring will work. When my van was sold (late last year) it was still holding.
The trick is to make sure the prongs are bent back to where they are supposed to be.

I did try first, and I had the worse result that some others had. I tried to bend the prongs back several times, and it must have to be just about perfect to hold. The injector o-ring was clearly big enough, since it squeezed into the cup, but it didn't hold. It took a bit of driving before it leaked though. No gas on the initial start-up. Since I've tried a few times and it doesn't seem to be working for me, I think I'll bite the bullet and get the fuel rail. The cheapest I can find it is $109 though, must've went up. http://www.factorymoparparts.com/04861498ad.html

Thank you georgef for the info!

atoman

· #49 · Feb 4, 2016

georgef said:
Part number 4861498AB or 4861498AC for 2001 thru 2002 is available from Rockauto for $75 plus shipping.

Part number 4861498AD for 2003 thru 2007 is available from Rockauto for $113 plus shipping.

You can find a 5% off discount code here: RockAuto Introduction & Discount Code!

morggab said:
I did try first, and I had the worse result that some others had. I tried to bend the prongs back several times, and it must have to be just about perfect to hold. The injector o-ring was clearly big enough, since it squeezed into the cup, but it didn't hold. It took a bit of driving before it leaked though. No gas on the initial start-up. Since I've tried a few times and it doesn't seem to be working for me, I think I'll bite the bullet and get the fuel rail. The cheapest I can find it is $109 though, must've went up. http://www.factorymoparparts.com/04861498ad.html

Thank you georgef for the info!

Try rockauto.com as suggested above.. (search for the specific part# via their search box)

Reactions: 1

wayneh

· #50 · Feb 4, 2016

Mine was $67 delivered, from an e-bay source. It looks like they've gone up a few bucks to $75.

http://www.ebay.com/itm/Dodge-Chrys...ash=item1e9ec026a0:g:wLAAAOSwyQtVn2mQ&vxp=mtr

itsallgood

· #51 · Feb 5, 2016

morggab said:
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.

ramby

· #52 · May 30, 2016

fuel damper leak

I have a 2001 dodge grand caravan 3.3L. My damper is leaking at the very top center of the hat. It is corroding. Van has 212k miles. I applied cold weld to the top and down the sides of the hat. I have not read in this thread about the hat leaking at the very top due to corrosion so thought I would post it. If my fix should fail I will post the failure. I ran the engine twice today looking very carefully for the exact point of leakage and this is all that is leaking. I have no fuel leaking on the rail or lower. Fuel just sits on the hat and brim and evaporates almost a fast as it leaks.

blknblu

Discussion Starter · #53 · May 31, 2016

sold my 2001 last year, with my fix still holding

LEVY

· #54 · May 31, 2016

atoman said:
IMHO, those fuel pulse dampers were a hasty solution to the problem of leaky fuel rails that goes back at least to mid 90's. The pulsation of liquid fuel caused by injector pulses sometimes caused resonance (hitting a "natural frequency") and caused catastrophic failures and fires...

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.

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itsallgood

· #55 · Jun 1, 2016

LEVY said:
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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offgas

· #56 · Jun 1, 2016

I don't have a van with this type of rail, so I don't know how it is constructed. Is it possible to weld, braze, etc. the hat to the rail? Just curious.

LEVY

· #57 · Jun 1, 2016

offgas said:
I don't have a van with this type of rail, so I don't know how it is constructed. Is it possible to weld, braze, etc. the hat to the rail? Just curious.

I haven't looked at the design but, if it is leaking from anywhere else other than the O ring, then the internal diaphragm is probably ruptured, and a new unit is in order. You might be able to stop the leak but, this device is not longer working as it should. If you "fix it", then you will have leaks somewhere else (more dangerous and expensive to fix). I would think manufacturer design was to allow it to leak once the internal diaphragm is ruptured, so you can notice it and replace it ASAP (it should also have some kind of vent to the atmosphere so the diaphragm can freely move).

offgas

· #58 · Jun 1, 2016

Thanks, LEVY. I didn't know there was a diaphragm in it, which would be destroyed by the heat of welding, etc.

LEVY

· #59 · Jun 1, 2016

offgas said:
Thanks, LEVY. I didn't know there was a diaphragm in it, which would be destroyed by the heat of welding, etc.

I didn't either!

But being a dampener, it should have a diaphragm and spring.

Again, if leaking past the diaphragm, it means diaphragm is ruptured.

Remember the old mechanical fuel pumps?, once the diaphragm was ruptured, it would leak gas to the floor. Some very smart people would seal that little hole on the fuel pump case thinking they solved the problem, all they did was to allow that leaked gas to reach the crankcase insted of the floor. That little hole was there (in the bottom part) for a good reason.

JCamasto

· #60 · Jun 2, 2016

Link to the "internal diaphragm" ?

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