porcupine73 Posted August 12, 2013 Share Posted August 12, 2013 Hi, what's a good way to fix a section of rusted out fuel line? It's on my '96 Legacy brighton wagon. It's the lines under the driver side rear of the vehicle. It's steel lines that pass under the rear seat, through a rubber grommet, then there's some rubber hoses that connect it to the steel lines going to the fuel pump. The supply and/or return lines are rusted under the vehicle and are leaking pretty badly when the fuel pump is running. I think the vapor line is ok. The two main ways I can think are 1. Use a dremel to cut the lines under the rear seat, attach a length of 5/16" fuel injection hose, to a 90 degree elbow hose barb, then to the existing hose underneath. This seems like the easier approach, but having any rubber fuel line connections inside the passenger compartment seems like maybe a bad idea? 2. Use a dremel to cut the lines under the rear seat and use flare connections to 5/16" cunifer line. Maybe run the cunifer all the way over to the fuel pump since the existing steel lines above the fuel tank might be in bad shape too? http://store.fedhillusa.com/5168mmtubingandnuts.aspx I'm guessing the supply and return lines are 5/16" / 8mm. The rust monster is really getting to this vehicle. I've done the transmission cooler lines and rear brake lines because those rusted out in previous years. The fuel tank leaks if I put in more than 1/2 tank of fuel. My shop told me about $400 to put in a used tank. So I've been just running it at no more than 1/2 tank of fuel. Quote Link to comment Share on other sites More sharing options...
Legacy777 Posted August 12, 2013 Share Posted August 12, 2013 I think having flared connections in the cabin are probably better, but you'll have to see what is doable. Yes, the fuel lines are 5/16". 1 Quote Link to comment Share on other sites More sharing options...
porcupine73 Posted August 12, 2013 Author Share Posted August 12, 2013 Thank you, I will look into it. I think it would be safer flared also. I measured the supply and return lines, the o.d. is about .315" or 8mm. The vapor line o.d. is ,.262" or a bit over 1/4". Quote Link to comment Share on other sites More sharing options...
Fairtax4me Posted August 12, 2013 Share Posted August 12, 2013 Flare fittings will be fine as long as you can flare them properly. Dropping the tank sounds like it's out of the question because of the rust. Just run some hard lines above the floor pan under the seat and drop them through a hole drilled in the access cover. Pressure hose it from there. Shouldn't have to mess with the vent line unless you think it's rusted out too. IIRC the vent line hooks to the tank somewhere in the middle where you can't get to it without dropping the tank. 1 Quote Link to comment Share on other sites More sharing options...
porcupine73 Posted August 13, 2013 Author Share Posted August 13, 2013 (edited) Thanks that sounds like it would work. That way I could bypass the existing hard lines over to the tank which are probably pretty rusty too. I'll leave the vent line alone. Since the tank has a leak anyway it never builds up any pressure. Why the CEL never goes on because of that I'm not sure but the '96 were a little funny with their ODBII. Maybe I can get steel brake line already flared in 5/16" That would probably be cheaper than the cunifer. I think dropping the tank probably would be difficult because of all the rust. Dropping the tank it looks like you pretty much have to unbolt all the suspension, the differential, and crossmember for it to drop down enough to get the tank out? eta ... I decided to go with the 5/16" cunifer line. I've used that for brake line and it is very easy to work with. You can bend it by hand without kinking it and snake it around slight turns. So I think I can snake that over the top of the tank over to the fuel pump, cut the existing hoses where they connect to the old rusty hard lines, and slip them on the cunifer lines. I got these 5/16" double flare unions and nuts from Summit. These will make the union from the existing lines under the rear seat to the cunifer line. Amazon has them but takes too long to ship. Allstar Performance ALL50132 - Allstar Performance Inverted Flare Unions Allstar Performance ALL50140 - Allstar Performance Inverted Flare Nuts Edited August 13, 2013 by porcupine73 Quote Link to comment Share on other sites More sharing options...
Rooster2 Posted August 13, 2013 Share Posted August 13, 2013 Years back, I had a VW that had a rusted fuel line. A mechanic, who runs his own shop, fixed the problem by cutting out the rusted section, then inserted special high pressure rubber hosing to replace the steel line. He used 3 each worm gear type hose clamps on each end of the hose to prevent fuel leakage. I drove the car for prolly 10 more years, and never had a problem with this unique fix. I did keep an eye on the rubber hose to see if there was any deterioration, but none ever developed. 1 Quote Link to comment Share on other sites More sharing options...
ivans imports Posted August 13, 2013 Share Posted August 13, 2013 I fix rusted out lines dayly i put 5/16 high preshure line over the meatal line and clamp it i only use subaru stainless efi clamps as they do not cut into line and have a more + seal I find taking a length of wire tapeing it to line then feed wire thru and pull line thru with wire. I did change one proper way from front to back had to take out front and rear seat carpet seatbelt heater fan undoo ps side of dash was many hours and a real pain but doabble. 1 Quote Link to comment Share on other sites More sharing options...
idosubaru Posted August 14, 2013 Share Posted August 14, 2013 i'd probably look for high quality hose of some sort, but looks like you got it nailed. are you sure the tank leak isn't the lower fuel filler hose? with that much rust i can't imagine you haven't fixed it or had issues yet? Quote Link to comment Share on other sites More sharing options...
porcupine73 Posted August 14, 2013 Author Share Posted August 14, 2013 Thanks, yes, I think hose would be the quickest fix. I think I have a box of 5/16 fi hose somewhere. I might go that route instead of the cunifer once I get in there. The tank leak I'm not 100% sure. I noticed it drips if I get more than about 1/2 tank in there. It seems like it is coming from above the tank seam someplace. I can't quite see the source of the leak. I replaced the fuel filler neck a couple years ago but I'll have to take a closer look around in there. I don't mind running with just 1/2 tank but it would be nice to be able to fill up especially in winter. Quote Link to comment Share on other sites More sharing options...
idosubaru Posted August 14, 2013 Share Posted August 14, 2013 (edited) is a gas tank leak dangerous? i've never heard of anything happening but gas is volatile? Edited August 14, 2013 by grossgary Quote Link to comment Share on other sites More sharing options...
ivans imports Posted August 14, 2013 Share Posted August 14, 2013 Make shure must be High preshure efi feul line only !!! 80 psi min i like the good year stuff 1 Quote Link to comment Share on other sites More sharing options...
porcupine73 Posted August 16, 2013 Author Share Posted August 16, 2013 (edited) Thanks for the help guys it's fixed. I ended up using all 5/16" fi hose. I made sure to get the actual fi hose not just fuel hose. I put three of the high pressure oem style clamps on each line under the seat. It has a few tight bends in the hose but it didn't seem to collapse and it does run, so hopefully that will do it? I wanted to use the cunifer hard line but it was too hard to bend. I wouldn't have been able to route it from the fuel pump over to the lines under the rear seat. The smaller 3/16 cunifer is pretty easy to snake for brake line, but the 5/16" is much harder to bend, it can't really be snaked through blind areas. I was able to find the fuel tank leak. It's at the tank seam/weld above the driveshaft/exhaust. It's pretty rusty there. As long as I don't fill it it too much it doesn't drip. I'm sure that's not ideal but I think it's fairly safe still. If it were actually dripping all the time I wouldn't drive it like that but with no dripping at least I feel a little better about that. Edited August 16, 2013 by porcupine73 Quote Link to comment Share on other sites More sharing options...
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