Chrysler Repair/91 dodge dynasty fuel rail: 3.0L V-6
elbrant wrote at 2008-12-14 21:51:49
After replacing the fuel rail twice and having the same leaking re-occur at the u-bend we decided to go a different route.
We removed the fuel rail and cut it just before the u-bend. (There is a thick part that houses the internal o-rings).
We welded a half coupling 316 ss (stainless steel) onto each end and fitted it with solid brass barbed hose adapter.
High pressure fuel hose and clamps completes the assembly.
Stainless steel requires good welding technique. If you are not experienced in this area have a local shop do the work.
Size the fittings and hose so you don't starve the engine.
Total cost of this modification was less than 100 dollars, cheaper than a new fuel rail.
Larry Perkins wrote at 2012-08-13 04:59:32
I have what I believe to be *the* definitive answer to this situation. The "fix" costs about $10 and, if you are capable of being meticulous, can be applied without disassembling *any* of the engine. Unfortunately, it cost me about $100 and I had to disassemble two (2) engines (one in the junkyard; one in the backyard -- though some might not see the difference between locations). That others might benefit and, perhaps, spend the lesser amount, I post my experiences and discoveries here.
First, you need to understand that we live a bit "out in the country"; this being a weekend project, I bought *more* parts than needed as a hedge against breakage and in order to take care of "worst" case scenarios without driving the sixty (60) miles necessary to go pick up "just one more widget" should we run short Sunday afternoon.
I went to the local "U-Pull-It" outlet and disassembled a 3.3L V6 that, as luck would have it, was located in a nearly pristine '91 Dynasty. I retrieved the fuel rail and, using that as a guide, I procured some steel reducing bushings. My thinking went like this:
1. The fuel rail is supplied by hoses;
2. Many "aftermarket" fuel rails that claim compatibility with the engine attach the two halves with a hose;
3. I figured I could chuck the bushings into the lathe and turn them down until they just fit into the fuel rail, then solder or, more likely, braze them into place thereby providing NPT threads into which I could install a hose barb;
4. I elected to try this fix first because I figure that no matter how good an O-Ring you have, sooner or later it will leak -- a hose may fail too, but on an external barb, it could be easily replaced;
5. I reasoned that, on our car, I had a fuel rail that could be "risked" in this fashion because it was already leaking;
6. I further reasoned that if my plan could not be made to work, I would have the "new" rail from the junk yard that *might* work (given the pristine condition of the car, I was somewhat concerned that they had decided to scrap it because their fuel rail had started leaking and they didn't want to pay the $750 being quoted locally to replace it); and,
7. I did not disassemble the rail until the last possible minute because, despite the gasoline drip, it was still possible to start and move the car should an emergency arise.
So, Saturday, we took the engine apart. Thanks to Ronald's tip on how to disconnect the feed hoses from the fuel lines, I cast about and found a *short* open-end wrench that just fit over the steel pipes and used that to depress the plastic collars to unlock the fittings. This allowed us to take the fuel rail completely off of the car.
I put the inside (leaking) rail into the vise and cut the end off right behind the "O-Ring Collar" where the "swivel tube" entered -- basically, right next to the leak. Of course, after "forcing" the issue, what I *should* have done became immediately obvious! I saw there was a "ridge" pressed into the line and the O-Ring is compressed between that and the "cap" I had just cut off. Inside of that was a "slug" or "boss" with a hole sized to support the leading edge of the cross-over tube. As it turned out, this hole was perfect to accept a 1/4-inch, NPT tap! It took about ten (10) minutes to cut off both ends and run a tap "to the hilt" inside of this boss. Wrapped with numerous turns of pipe tape, I installed a couple of 3/8-inch hose barbs. Being larger than either the supply or the return hoses, I figured 3/8-inch should not "restrict" anything.
Now here's the really tricky part. Knowing the internal structure, I "circle cut" the second end -- taking the hacksaw and cutting just barely through the external tube. Had I done this with the inner rail still installed on the car, I could have carefully extracted all of the chips with a magnet and a bit of flushing. By not cutting into the tube past the O-Ring, all of the metal from the initial cut came away with the cross-over tube and the O-Ring. The chips from the tapping operation could have been removed with a magnetic probe (despite being "stainless steel," the rail is magnetic -- like a "400-series" stainless). If I followed this up with a good "flushing" (the inner rail is hooked to the supply line), I am pretty certain that no "chips" would have gone into unwanted regions. The outer rail, of course, could have been removed from the car once the inner one was cut free.
The point of all this is, with the hose-based solution, the intake system would not have needed disassembly; I wouldn't have needed a new gasket; et cetera.
Oh, and speaking of hose barbs, the local parts store gave me a good tip. (Yes, despite being "in the country, there is a "local" parts house about 1/2 mile down the road; unfortunately, they cater mostly to farmers and close up for the weekend on Saturday afternoon.) They had a supply of "Jiffy Hose" and matching barbs. The neat thing here is that no hose clamps are required. Simply slipping the fuel hose over the barb creates a connection rated to 300psi. The only down side is that removal means cutting the hose off of the barb -- there's no "going back" on this one. We simply cut the hose a couple of inches longer than needed so that we can remove and replace it a couple of times before a new one is needed.
Anyway, we fired everything up and tested it -- the solution works well. At $2.50 for the barbs and $2.00 for the hose (it takes a minimum of 11.5 inches), we were into it about $7.00 in parts. Figure another three bucks if you need a "plug type" 1/4-inch National Pipe Taper Tap, and you'd come in at about $10 and, maybe, an hour of labor if you cut the rail while it is bolted to the car.
Of course, as with all things related to automotive fuel systems, "your mileage may vary!" (Pun intended!)
Chris Rowland wrote at 2013-04-02 13:08:31
This worked perfectly for me (using the 1/4" tap. I used brass hose barb fittings and fuel injection rated hose (up to 100psi) and nothing has leaked since I did it. This method sure beats buying a new (and poorly designed) fuel rail for $450.
Photos are on my blog:http://therowlandestate.blogspot.com/2013/04/91-caravan-33-fuel-leak-from-fuel-r
Ken wrote at 2016-07-15 16:47:06
I fixed my '91 Grand Caravan by carefully cutting the raised end of each fuel line to expose the internal rubber o-ring and pull out the crossover tube in one piece. This minimized the metal chips, but I used a magnet to pull out any remaining bits. This was also a good time to remove the injectors and replace their o-rings, which gave me the opportunity to flush out the fuel rails with brake cleaner and compressed air blown through the fuel line openings in each rail. This was a good time to clean the injectors and replace their o-rings too. I then used 3/8" inch brass fittings with 1/4" barbs which were inserted into the tapped ends as described in earlier posts. One difference in my technique from the other posts was that I used 90° brass elbows, instead of straight ones, this allowed me to install a short fuel hose that arches between the two rails. It was a simple fix. This should be a permanent solution to my leaking fuel rail problem and will allow easy access in disassembly of the fuel rail in the future, if I ever need to work in that area again.