Mongo

I am creating a new thread on this to cease hijacking the other fuel line thread. I purchased Roger's EFI hose using the Gates barricade hose to replace the passenger feed line, which is under a lot of pressure.

I have had no problems with this hose, but hear that the barbed fitting Porsche uses can and will damage the new rubber replacement over time.

SeanR had mentioned Goodyear and Coline brand hoses with a special lining inside. This lining is called Fluoroelastomer, and is a blue color on the Goodyear hoses.

Other hosemakers such as Eaton and Continental use a black fluoroelastomer material.

I believe as long as the hose is J30R9 rated (minimum burst pressure 900 psi with an operating temperature of -30 to 275 degrees fahrenheit), it should be okay to use with EFI clamps.

Here is a link to the Goodyear hose on Summit.

http://www.summitracing.com/parts/gtr-65152

This is the Eaton Weatherhead product for sale at Napa. I am going to pick some up today:

http://www.napaonline.com/Catalog/Ca...510_0162709205

SeanR

Oh I surely did not recommend Cohline or Goodyear, I just said those were the only two that I've seen with the inner liner. I absolutely hate working with or using either of those hoses.

ETA: If I had to work with one over the other, I'd use the cohline hose. I'm not even sure how I ended up with 10 feet of that Goodyear stuff.

Mongo

Correction, you do not then. However, if it is a 'safe' hose to use, then why not?


EDIT: Also, Cohline hose may not be compatible with fuel in the United States due to some additives and ethanol. I could be wrong though.

GregBBRD

I believe that you will find that the fluoroelastomer material is actually a major part of the problem.

This material is, from what I've seen, relatively soft and thus cuts very easily on the barbed fittings.

Mongo

So what lines out there will work then if some sort of plastic is needed to prevent deterioration? Rooster teeth reinforcement???

MjRocket

Why not just bite the bullet and make a wise investment on Greg's lines??

j.kenzie@sbcglobal.net

Obviously manufacturers cannot recommend this, but it seems that you could use abrasives to dull the sharp edges of the barbs, so they cannot cut the new hose.
You did not hear this from me.
Good luck,
Dave

MainePorsche

Did you say something Dave ?

Eplebnista

The original Cohline hose had a relatively hard plastic inner and a rubber outer. You can reproduce this hose using nylon fuel line inserted into the Gates Barricade hose:

https://rennlist.com/forums/928-forum/726377-diy-nylon-core-fuel-lines.html

This has worked for me, with the caveat that you have to remember that pulling the nylon inner through the Barricade hose stretches the Barricade and you have to give that some time to retract before finishing assembly.

On the other hand, I can't imagine why grinding the sharp edges of the original barbs down to a more friendly profile won't work.

Frankly, I think no matter what you do, including buying Greg's bulletproof hoses, you are nuts if you don't give your fuel lines a once over on a regular basis.

NoVector

And related, what are people doing to keep the clamps from backing out? Does red or blue thread locker work? I had a "holy cow" moment when doing my intake this year and found 2 clamps had backed out and were loose. I saw in the other thread that Rob Edwards had the same problem--so I'm thinking this could be a common issue too.

Eplebnista

You don't have to use screw driven clamps. Oetiker clamps work and have been used in this application by many OEMs for decades. You would have to buy or make another tool, but that has never bothered me. The hoses that I fabricated with the nylon inner don't need no stinkin' clamps. It isn't coming off those barbs unless or until its material properties are changed significantly.

Mongo

As an FYI, the Loctite blue I used on the passenger fuel feed line still is keeping those clamps from backing out. I just checked them this morning after two years of being on the car with that rubber hose used.

GregBBRD

I don't see how a hose clamp could work its way loose.....the internal friction of any "threaded" hose clamp I've ever used is very high.

Rubber and all the synthetic rubber hose I've seen "shrinks" with age and heat....making any clamping technique become loose, over time. Just look at the crimps on A/C hose, crimps on the oil cooler hoses, crimps on the automatic transmission hoses, and crimps on the power steering hoses.

I replace hoses for all these applications on a daily basis...I've literally got thousands and thousands of dollars invested in inventory of new Porsche hoses and lines. The unique thing about almost all of the hoses is where they leak....at the crimped junction of the steel line and the rubber hose.

The Oetiker clamp has some unique properties. Properly sized for the hose they are used on, they offer increased clamping forces and because of the design, they also offer more residual spring tension on rubber hose as it shrinks. I supply them with all of my automatic transmission hose repair kits and power steering return hose kits. They work fantastic over the fittings on these hoses, which are completely smooth and designed for a rubber hose and either a crimp or a clamp.

Do they work good over any fitting with a barb of any sort? Well, since they do apply increased pressure on the hose for better retension, what does that mean for the rubber hose where it contacts the barbs?

I'm a pretty big stocking distributor of Goodridge hose and fittings (J2 Precision Hose). I sell quite a bit of their "pushlock" product, where rubber/synthetic rubber hose is pushed over barbed fittings. This stuff works amazing well and I recommend it for many applications (fuel is not one of them, BTW.) However, there's some interesting facts about this hose, which is relative to any conversation about rubber hose being put over anything that is barbed.

First of all, the hose and the fittings are designed to work together. If you push a piece of "pushlock" hose over a pushlock fitting, you are never going to be able to pull it apart....the only way to get it back off is to cut the hose.

Is this true when you push any aftermarket rubber hose over the barbs on a 928 fuel system designed originally for plastic line? Well, to save you time, it is not true.

Is this true when you push a piece of the correct German rubber hose over the barbs on an early fuel injection rail? Yes, it is...the only way to remove that hose is to cut it off!

Secondly, the "pushlock" hose is designed to never have a hose clamp placed over the hose....as a matter of fact, they specifically warn you not to do this. Why? Because the clamp cuts the rubber hose at the peak of the barb.

This entire thread, all of the threads before it are really very simple:

Rubber hose over the barbs made originally for plastic line is the wrong application.

Mongo

I remember when doing my efi hose I questioned the sharpness of the barbs. For some reason? Mine did not appear to be as sharp as other applications on here.

ROG100

I SELL LOTS of Greg's hoses and think they are THE best choice for fuel applications.

I also agree with the general statement that a rubber hose over a sharp barbed fitting is not ideal - does it work? yes it does. Should you do it? Only if you know what you are doing and accept the liability for doing it. This also means checking the hoses on a regular basis and ensuring the clamps are tight. I would also recommend changing them every 10 years. Rubber hose over a none sharp barb works well and Porsche use that method on the 928 and most other P cars of the same vintage.

The bigger issue to me is the effect of ethanol on old technology hoses. The PTFE liner on the Cohline (Porsche) hoses seems compatible with the **** in our gas. GB's hoses are of course.
However if you use over the counter EFI hose better to go with Gates Barricade.

If you are trying to keep costs down some of the fuel hoses for the 32v cars are still available from Porsche and I stock those also. They are also current manufacture not NOS. Those in conjunction with GB's hoses make an ideal choice.