change platic fuel lines or not????

[Will98D]

I've heard people argue both sides of this one: do you change the plastic fuel lines running through the tunnel? If so, metal lines or plastic? Metal supposedly make noise. Anyone know of a gas-compatible plastic that can replace the existing lines. Mine are still quasi-flexible and no cracks, but 27 yr old plastic.... I'm not to thrilled about the idea.
WD - '74 914/1.8

[captjm]

I have been wondering this too. I will be replacing the tunnel fuel lines using steel brake lines as noted in the tech article here. I have heard of soft copper line being used-- possible dis-similar metal problems maybe with copper. Stainless braided ($$?) is also an option as well. I have heard of fires in the engine bay due to a broken fuel. I wonder how many 914 have really suffered a broken TUNNEL line?

[ovilla]

I'm contemplating the same thing while I yank out the gas tank for a sway bar install. Anyway, did you know that the Dodge Durango SUV uses nylon (plastic) gas lines? Read it today in the sales brochure from Dodge.

[Dave at Pelican Parts]

A few points to ponder:

The plastic lines have lasted 25-30 years so far. They tend to hold up very well when they aren't exposed to heat. Which means that they can have some problems at the rear firewall... But it is likely that new ones will last a good long time as well!

Second, copper is a Bad Idea. The stuff that is easiest to get work-hardens, which means that when subjected to vibration it will get brittle and eventually crack. Oops.

Third, stainless-steel braid makes a really wonderful file. That's not the sort of thing I want to have right next to my brake lines, my clutch and throttle cables, my main wiring harness, my shift linkage....

Either stock plastic, or stainless-steel "hard" lines would seem to be the way to go. There are truck brake lines that are the appropriate sizes. You can even put bubble flares on the end (like on the fuel rails) so that the hoses have even less of a chance of slipping off.

--DD

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Pelican Parts 914 Tech Support

A few pics of my car: http://www.pelicanparts.com/gallery/Dave_Darling

I changed mine out about 6 months ago. I grabbed both of them and yanked them out!

About 2 seconds later I wondered if I really should have pulled them out or not. The plastic felt and looked like it was in great shape until you got to the ends near the motor. If you're cheap (on a budget), the best way would be to cut off the ends and couple new hose to them.

If they still make the original lines and they are not to costly the OEM would be a fine way to go IMO. They've lasted 25+ years.

I went ahead and did the steel conversion and had fun making a project out of it. I had my car apart and I installed the lines in about 3 hours. However I think I'm slow and a little picky when I work in my car. Others could to it quicker I'm sure. If I ever drive it I'll let you know if they rattle or not.

my 2 pennies worth

[captjm]

Another comment or thought about potential rattle of steel lines--- I plan on using some wire shrink tubbing from the local electronics store to prevent the rattle. I hope it works.

[Roland Kunz]

Hello

The 914 have different materials.

The early up to 74 have clear PVC lines with steel ends to the fueltank.
The later 914 with front fuelpump complete Teclamyt PVC runing in one piece from fueltank to engine.

The PVC lines can get gracked. Mostly the sharp bow to the right and all other in the enginbay exposed lines will gethard and brake if you "touch" it. I also had once the problem that the front section in the joint to the metall line had a fine crack.

The later teclamyt lines only make problems if the battery acid work on them.

5 years ago the Teclamyt lines where still aviable at Porsche.

The highest break potential are at the point the lines emerge from the downside into the engine bay. Direct on the battery post the rubbersleeve gets eaten up over the years and the also weaken fuelline shuffles against the sheetmetall cutout.

Grüsse

[Jim Smolka]

I beleive Pelican has the plastic lines in stock.

Also, I replaced my lines with Alum from Jegs and install AN fittings onto the ends. Then I used SS braided lines from the pump to the hard lines.

[bowlsby]

I've had thickwall aluminum tubing on my car for over 2 years with great results. I think its used for icemakers in refrigerators, from a plumbing supply store.

Inexpensive, easy to bend yet stout, same ID as stock. Mates to rubber fuel lines easy.

[bowlsby]

Just remembered, I tried the large diameter stainless and just could not get it to bend without splitting. Maybe there is a better brand or a better way, but I had no success after several attempts, which is why i went with aluminum.

[Dave at Pelican Parts]

Oops, I forgot about the aluminum tubing. Yeah, that should be fine. It doesn't work-harden the way soft copper does.

--DD

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Pelican Parts 914 Tech Support

A few pics of my car: http://www.pelicanparts.com/gallery/Dave_Darling