1991 GMC suburban braided fuel return line at back of engine 5.7

[williamrustyandgu]

Hi,
My name is Mike, I have three square body trucks. 1979 Chevrolet K20 custom deluxe, 1982 Chevrolet C20, and 1991 GMC v1500. My issue is with the GMC. I have a leak in the braided fuel return line that runs up the back of the engine on 5.7? It is a very specific part with the fittings, length, Etc. I am having a hard time locating the correct part, or even figuring out what the correct part is. I have a guy that says he can make one... which is okay I guess if I cannot find the correct part. Wondering if anyone have a part number or know of a good source To find the correct part? I have already checked with LMC truck, and some others. EBay shows a bunch of parts that could be correct but I don't want to order something I'll have to send back. Any help on this issue would be greatly appreciated! I am new to the site but expect I will be spending a good bit of time here....thanks.

 

[Ricko1966]

Welcome. Is it leaking in the braided part it's self not the connection? If you are sure it is the return side not the supply side,there is almost no pressure in that line unless it is plugged some where. That being said. I'd have no problem removing the line,slitting the crimps,to reuse the O.E. ends and make a return line. . If you end up going that way post back on a new thread for guidance,unless you already know how.

 

[edgephoto]

My 1987 with TBI needed a couple of fuel lines. One the metal was corroded and leaking fuel on a pressure line and the other was a feed line too and the braiding was all frayed. I am restoring the truck and wanted to replace the fuel lines. I could only find a couple of NOS ones but not enough to replace them all.

I ended up making lines from braided hose and used AN fittings. Not ideal but it should work good.

 

[1STLS1]

Hello, I have been fighting this the past couple weekends myself on my '87. I was replacing them because I was swapping an engine and just due to age. I stepped up and bought a pair of pre bent lines represented as being correct for my 1987 V-10 5.7 truck that had the stainless wire braided hoses just line factory, all well and good but they didn't fit. I don't remember the brand but they were expensive, like $150-170. They were close but on that truck there is no room for error if you are going to reattach it to the back of the cylinder head like the factory. After trying to fit them to the engine on the stand and then in the truck I am making new hoses out of 6an and fittings and chalking it up to experience.

 

[Ricko1966]

The return line has very,very little pressure, decent fuel hose and clamps using the same common sense as plumbing a mechanical pump.The pressure side is a different story.

 

[HotWheelsBurban]

Dad and I had to replace these lines on our '90 R2500 5.7 TBI several years ago. The biggest issue I remember was having to get on top of the engine and work down behind it, and there is not much space back there. Getting the lines snaked up from the bottom, between the firewall and transmission, was fun too....I was laying on a big piece of plywood that was laid over a couple of 2x6 boards; we'd had a big lunch before starting the job and it's not a good idea to do that if you're gonna be laying on your stomach for a few hours! But we persevered and got it done, truck ran better without suspect, leaking fuel lines too. IIRC the fuel lines came from a local parts store, but this was like 15 years ago and I didn't know about online parts stores then.

 

[77Dmax]

Tbi is 15 PSI, decent rubber hose and clamps will get you by in a pinch. I don't recommend it for a long term solution though.

 

[Ricko1966]

It's 15-20 lbs on the pressure side return side is very low. And if you are concerned take a look at an older BMW,PorscheAudi,Volkswagen,Mercedes,etc That had Bosch D jetronic,L jetronick or K jetronic,even the old Nissans,they were running 35 psi through injection hose and injection hose clamps. Pic of the type clamps,and some ebay 914 injection stuff for illustration purposes. I wouldn't like it pressure side,I don't like pressure side on carbs I make steel lines. But if you can't find what you need especially low side( return ) I'd use good hose and good clamps. If you split and peel a factory crimp you can usually use the factory ends. Sure I'd rather have the correct line,but done right I wouldn't have a problem using a well done hose and clamp repair temporarily as many years as it took to find the right parts. Watch at least the first few seconds of this video,the clamps are explained.

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[Vbb199]

Return should be m14, sending line i think is m16

You can get earls adapters to go from 14mm male to a common 1/4" nipple