Goughary

Lately is seems i start one thread, don't finish, move to the next and then the next...kinda like my life at the moment....works in progress.

But, since i had a pile of old crappy fuel lines, and the idea of making fuel lines has been in my head...and the cohline crimp tool i bought will do small and large crimps...it's worth exploring, since we all need to do fuel lines. Granted, i haven't decided if i will ever do fuel lines for anyone else, as that would have to be on a "use at your own risk" basis. I wouldn't want the liability.

Anyway...it's fun to learn. So today i took one line - cut off the crimps, cut into the line and removed it from the ends, polished and nickel plated the ends, and got ready for reassembly when my reassembly tool shows up on July 7.

There is a lot of information on the interwebs regarding putting lines together, and as is typical w the interwebs, you can trust only of fraction of it. (This also goes for plenty of the terrible advice on rennlist, btw)....there just aren't a lot of old farts with many years of experience giving away their knowledge or spending millenial-worthy time on their phones yacking into hyperspace. Though i admit, on this forum, we have quite a few old farts and some of them, when they aren't being grouchy, are quite knowledgeable...

..and now that I've offended all of old-fartdom, somehow i expect them to come here, read this, and participate? I may have just completely screwed my self...but i can tell you this...we will from here out, probably only hear from those with a sense of humor! Which is good. Because my mood is going to be in the dirt once i use these lines, my engine bursts into flames and my house has burned to the ground....

So on to the thread we gooooooo...

Goughary

This is the line i chose. Kinda non-descript. I chose it because it doesn't have to be clocked from one fitting relative to the next.



Next i cut into the crimp- you'll notice on the oem lines, these aren't "crimped". They say, on the interwebs, that the crimp is only there to protect the end of the hose and it's the barb that actually holds the hose from backing out. (This is where old fart w 30 yrs experience chimes in and gives correct answer) (or maybe 40)...



Then with a razor blade, i carefully cut the hose end down and broke it free of the barbs...being careful not to score the barbs.

And wallllaaaaaa



Pieces. Bits and pieces...

Before we move on...here is another area where i am weak on knowledge - the older lines i typically see on our cars are cohline 370....what came before that? I thought the early lines did not have a plastic, or polyamide core. And Cohline 370 does...





Anyway- we are replacing with cohline 3124. I was going to use gates barricade- the type made for high pressure applications- but again, a report from the interwebs says "don't use that with barbed ends, because though it has a polyamide core, it has a rubber lining inside the polyamide core and therefore the barbs will cut that rubber lining, weakening the hold on the barbs".

So because I'm ignorant, I'm going with what i know will work, Cohline 3124.





So let's take a look at the ends after removal.





And into the plating bath they go. I have been experimenting and working on my plating setup- now adding a magnetic stirring device. Next I'm changing my power supply to something more powerful with more control. But for now this is functioning well.



And pow! Bright happy nickel...









That's all for today. I'll now just wait for the reassembly tool and put it together next week.

Things i don't know are- why aren't the oem lines crimped. And does the end have to be softened prior to installation? There was a report of putting the line end in boiling water prior to pressing onto the barb. Others have said assemble dry.

Then after i assemble, I'll have to rig up some way to reliably pressure test...and that will be that.

Then I'll need to practice. So if anyone has a bunch of old oem 964 fuel lines laying around, please Pm me. I'll gladly pay the shipping if you had otherwise intended to throw them away. I'd also like to cut into and dissect some verifiably original (aka from 1990) lines to see how different they are.

RicardoD

It is the nickel plating at home that takes this from normal to the madness end of the spectrum.

What is the re-assembly tool if there is no crimp?

Goughary

The hose has a hard polyamide core, and that core stretches over the barbs. So you can't just push the hose onto the end. You either rig up a press tool, which many have done, or you buy the Dorman tool. There are a few very expensive tools that are maybe better. But i think for what i need to do, the Dorman tool will be fine.

Anyway, apparently the polyamide tube is the fuel line. The rubber is protecting that tube? Again, more info from the millennials of the interwebs.

cobalt

Always interesting read. I believe you are correct the Polyamide is the fuel line the rubber is a protective casing. I just bit the bullet and replaced all my lines with factory. I couldn't tell a difference in feel of the lines from old to new. My old lines flexed and the same as the new and seemed fine but I figured my time was more valuable than the $600 or so I spent on new lines. I was upset that some came yellow cad (could be zinc) and others silver not sure what coating but look like yours. Old line is further away. IIRC the cohline was a different number than the original but will need to check and report back. Is the 3124 what was originally used?

Goughary

Cohline 3124 is what we buy today (belmetric is where i bought) and i had thought that the 370 was the original. But someone with original lines still on their car should chime in...(obviously before their car bursts into a fiery ball of rearward facing flames)

cobalt

I will check my old lines and report back. So I must assume the new factory lines are the 3124 which I believe are more impervious to alcohol.

Interesting thing happened the other day to a friend. For no apparent reason the O ring at the top of injector # 2 just blew apart and started spewing fuel all over the place. I had never seen this happen before. No signs of issues until he went to start the car and immediately smelled the gas. Lucky for him it wasn't a hot engine. So I guess replacing all seals and fuel related lines is a good call. The biggest issue is the long hardline from the front of the car to the rear with the small rubber line attached to the end. So far I haven't decide to attack that one but might look into what you are doing since it is so expensive and costly to ship or just make a new rubber fuel line to replace it.

I will probably rebuild my old lines to use on other cars in the future.

Ubipa

The OEM lines off my 92 are Cohline 370. The 993 fuel rail setup I replaced them with looks like it came with a VRT polyamide hose.

Cobalt - My supply line to the engine, initially looked ok and then as soon as I moved it... the cracks started happening. Those original PTL? hoses appear to be bonded and the cracking is on exterior layer.

RicardoD

My 1990 C4 has Cohline 370 original lines.

JasonAndreas

Some of the lines are crimped and those that are polyamide are not. The barbed fittings for the polyamide lines require a hydraulic press/gun to fit into the line.

wallra

I thought about using nylon tubing. this is what all new car use. get rid of all the rubber. never dry rot.

titleistaddict87

Wallra: Can you expand on using nylon tubing? Originally I bought Paul Mason's lines but there is a supply chain problem so have been looking at alternatives while I wait...

wallra

they make different sizes but you slip it over the barbs

Goughary

Thanks Jason. I imagine there shouldn't be any harm in crimping the lines...just to add support to. It back out.

Fwiw...i bought the line press tool to install the lines onto the barbs. That's arriving Monday. So it'll be interesting to see how that works.

JasonAndreas

It is semi-rigid, similar to PEX but without the shape memory. If it cracks, especially when below freezing, I imagine you are done for.


Very cool! Which tool did you buy? The modified vice-grips, the block & cutter or the hydraulic model? Definitely looking forward to see how it works too.