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Fuel line leaking

4K views 29 replies 5 participants last post by  97tacomaHA 
#1 ·
Hi folks. I replaced the fuel tank in my 1993 corolla because I thought it was the source of my fuel leak. It wasn't, but it had some rust holes in the top so it was due anyway. I noticed that my fuel lines are very crusty and the return line has a pretty serious leak, about 1 drop every 4 - 5 seconds. I put some JB Kwik Steel on it but it doesn't stick well because of the rapid rate of leakage. I was thinking of just getting a compression fitting and a short piece of metal line since it is so close to where it goes into the rubber line. My question is, does anyone know what size the line is? The guy at autozone seemed to think that it was 5/16" but that seemed a little big. My other thought was to just cut the line right before the leak and put some rubber hose on it and run it right up to the top of the tank, but I don't have any way of flaring it so I am not sure if it would stay on or not. I do have fuel line clamps but I am not sure if they would hold.
 
#2 ·
I've found that Gates hoses seems to fit the best. I think they make 1/4", 5/16" and 3/8" fuel return hose. 1/4" might be what you need. It's hit and miss whether local parts stores carry the bulk hoses that they cut to length. Around me O'Reilly and NAPA sometimes has it. One location may have it and another not.

Not sure about your other questions.
 
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#4 ·
I would guess something metric, rather than the 5/8ths" the McParts store clerk suggested.

I think all McParts stores around here (Autozone, Advance, O'Reilly's, Pep Boy's, and NAPA) have spools of all different kinds of hose stock unless they recently disco'ed it, but they keep it in back and you have to ask. They'll often bring you back there to look at it, and that's a good time to match it up using your own eyes.
In today's world, it's extremely possible that you need to inform the clerk that they do indeed carry such items. The hoses might be near their bulk rolls of metal brake tubing stock that nobody knows they carry...
 
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#5 ·
1/4" = 6.35mm, so maybe the original rubber hoses were 6mm, but a lot of the 7th gens were built in the USA so maybe they went with standard sizes available. The outer texture on Gates hoses seems to match the texture on the original hoses (fuel, return, PS return, ATF oil cooler), so I speculate that they were the original supplier.
 
#7 ·
Well folks I am going to bring this one back up. I fixed my leaking return line but cutting about 10" of the line off and putting a bubble flare on and running 1/4" rubber line up to the tank. It works but even 1/4" seems a bit loose. Something hit my line and sliced the rubber line and I had to replace it again. It was a quick easy fix. I notices all of my lines are starting to "sweat" but not leaking. What I want to do is replace both return and the main feed line with nylon. They have metal to nylon fittings. Do you guys think 1/4" would work for the return lines and 3/8" for the feed? My plan was to cut the good metal ends off or flaring new metal ends and then converting them to nylon in the middle. Actually, my plan is to cut them off of a car at the junk yard and then replacing them from there. Any input would be helpful. I am planning on doing this in the spring and just dealing with the sweating lines since I don't have a garage and I wouldn't want to do the fuel lines inside anyway.
 
#27 ·
Well folks I am going to bring this one back up. I fixed my leaking return line but cutting about 10" of the line off and putting a bubble flare on and running 1/4" rubber line up to the tank. It works but even 1/4" seems a bit loose. Something hit my line and sliced the rubber line and I had to replace it again. It was a quick easy fix. I notices all of my lines are starting to "sweat" but not leaking. What I want to do is replace both return and the main feed line with nylon. They have metal to nylon fittings. Do you guys think 1/4" would work for the return lines and 3/8" for the feed? My plan was to cut the good metal ends off or flaring new metal ends and then converting them to nylon in the middle. Actually, my plan is to cut them off of a car at the junk yard and then replacing them from there. Any input would be helpful. I am planning on doing this in the spring and just dealing with the sweating lines since I don't have a garage and I wouldn't want to do the fuel lines inside anyway.
i noticed sweating too on my line or it was 'moist' not due to rain or the sheep fat i was spraying on them, especially the main fuel tube deep in the underbelly inside the plastic protective channel
what exactly causes this sweating with the 'mild' corrosion and not a perforated hole to induce leaking fuel

I got a set of straps and put them on my '93, but I don't remember where I got them. They weren't very expensive though, maybe around $20 IIRC.
i have since noticed my tank only has ONE strap so idk what the deal is going on underneath there,
 
#8 ·
You want as much metal line as possible, as you found out.

In my opinion, you're better off cutting up a good metal line to get it into the car, and then splicing it back together short lengths of fuel-rated hose and clamps. If doing that, you should flare ends of the metal line.
 
#9 ·
What kind of hose (brand and type) did you use? The return line has no pressure, so it shouldn't be sweating. Maybe it's just condensation of water vapor from the lines being cooler than the outside air?
 
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#29 ·
perhaps? idk!? i recall wiping my rotted return line where coating was gone clean before removing, it immediately started sweating and smelt my fingers after rubbing and it definitely smelt of petrol!
 
#10 ·
I got whatever brand fuel hose that they sell at Advance auto. It looks like it actually tore. I have no concern with running Nylon line. My Chevy has almost all nylon line it and it has no issues. I think the line that is sweating is the main feed line. I just need to find out what size to buy before I rip it all out. I will see how much of the line I can get from the junkyard. Luckily the yard I go to pulls the tanks so that should save me a bunch of work.
 
#12 ·
So I went to the junk yard and they had a 1996 corolla there. I pulled the lines and they are actually in really good shape. They have a little bit of surface rust and some pitting where all 3 lines turn to go up towards the tank. I sanded the scale off and I think I will cover those areas with some steel stick just as some added protection. Either way I got a really decent set of lines for a couple hours of work and $6. I plan on throwing them in this weekend if the weather cooperates. I guess I lucked out.
 
#16 ·
Well, I got the lines in Saturday afternoon but of course it got dark by the time i was done. I started it and I got a drip.

Here is the old lines. I am not sure why my camera wouldn't quite focus
287862


Here is where the leak was coming from. The nylon line that comes down from the pump on the feed line kinked and got a tiny hole in it.
287864


Here is the joint I got to fix it.
https://www.amazon.com/gp/product/B000CIR1P2/ref=ppx_yo_dt_b_asin_title_o06_s00?ie=UTF8&psc=1
287866


And here it is installed. I just cut the steel line and the nylon line and spliced them together. These compression fittings work fantastic.
287867


I drove it around yesterday and drove to work today and no more leaks!
 
#30 ·
Well, I got the lines in Saturday afternoon but of course it got dark by the time i was done. I started it and I got a drip.

Here is the old lines. I am not sure why my camera wouldn't quite focus
View attachment 287862

Here is where the leak was coming from. The nylon line that comes down from the pump on the feed line kinked and got a tiny hole in it.
View attachment 287864

Here is the joint I got to fix it.
Amazon.com: Dorman 800-135 Nylon to Steel Fuel Line Compression Union : Automotive
View attachment 287866

And here it is installed. I just cut the steel line and the nylon line and spliced them together. These compression fittings work fantastic.
View attachment 287867

I drove it around yesterday and drove to work today and no more leaks!
this is an interesting approach to that flexitube, did you get the flare fitting removed from the main tube? or just cut the main hose, its made of nylon and no flexi metal braid inside of it
 
#17 ·
Was just watching a video on youtube and watched a guy use one of those to patch a leaking airline which went to the PTO controls on a big truck. Apparently, those used to be considered a hack-ish repair, but they now come OEM on new trucks!
 
#21 ·
this rotted crap could have all been prevented :(
 
#28 ·
McParts store perhaps?
 
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