Author Topic: Replace leaking fuel lines on MK2 with viton?  (Read 5288 times)

November 07, 2007, 06:12:22 pm

wahlet

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Replace leaking fuel lines on MK2 with viton?
« on: November 07, 2007, 06:12:22 pm »
Will Biodiesel / SVO work in a MK2 in original rubber/plastic fuel lines?

And sub-question: has anyone done a fuel line swap on a MK2?  Got any hints?

Lately my Jetta's developed a habit of shuddering at road speed.  I've traced it to bubbles in the fuel line (to inj. pump).  I've deleted the water trap under car - it was broken anyway, and have replaced some hose clamps.  Also checked fuel pickup / sending unit in trunk.  Jetta runs better but not perfect.  Figure I might as well replace lines and do 2 things at once: remove bubbles, and make compatible with Biodiesel (if necessary).

Thoughts?
1991 VW Jetta 1.6L NA diesel

Reply #1November 08, 2007, 09:14:31 am

pariah

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bio
« Reply #1 on: November 08, 2007, 09:14:31 am »
i have heard viton is the shisnit but costs a bit... have been running B100 through polyurethane lines for about 4 months and they are just like the day i bought them... my rubber lines lasted about 3 weeks and started to sweat.... after 2 tanks of bio its a good idea to change your fuel filter... i have a mk1 all the lines were 5/16" (8mm) except from the filter to the pump that short one was 1/4" (6mm) and off of my tank there was a odd section that was 3/8" (10mm) to 5/16" (8mm) that i just made sure my hose clamp was positioned well that has worked with no problem using just a 3/8" (10mm) section then theres the tiny injector hoses.... it took me less than 30 min to change all the hoses definately worth it....

Reply #2November 08, 2007, 04:53:46 pm

wahlet

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Replace leaking fuel lines on MK2 with viton?
« Reply #2 on: November 08, 2007, 04:53:46 pm »
Thanks pariah.  What other materials will work?  Viron, polyurethane?  Where's a good place to get this stuff?
1991 VW Jetta 1.6L NA diesel

Reply #3November 10, 2007, 01:34:24 pm

pariah

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poly
« Reply #3 on: November 10, 2007, 01:34:24 pm »
i got mine here
 http://procycle.us/main/fuel_hose.htm
i have also heard that silicone and if you are ambitious stainless steel works
do not try vinyl... :)

Reply #4November 10, 2007, 02:15:51 pm

burn_your_money

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Replace leaking fuel lines on MK2 with viton?
« Reply #4 on: November 10, 2007, 02:15:51 pm »
MK1s have steel lines, mk2s have plastic (under the car)

You'll be in for more then 30 minutes of work
Tyler

Reply #5November 10, 2007, 02:23:13 pm

wahlet

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Re: poly
« Reply #5 on: November 10, 2007, 02:23:13 pm »
Quote from: "pariah"
i got mine here
 http://procycle.us/main/fuel_hose.htm


Is that polyurethane hose rigid enough to handle the vacuum pressure?  Is it rigid enough to clip into the plastic clips under the car and keep from sagging in between?

If so, it sounds like a good option, and cheap!  I almost bought the viton kit from Greaseworks.org today for $100+.
1991 VW Jetta 1.6L NA diesel

Reply #6November 10, 2007, 09:42:09 pm

bigblockchev

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Replace leaking fuel lines on MK2 with viton?
« Reply #6 on: November 10, 2007, 09:42:09 pm »
I have been running B100 for the past 2 years. The only issue that I have had is with the injector return lines. I got some viton from Mcmaster Carr and  replaced them and all has been good so far. I have not noticed any leaks or deterioration on the rest of the lines. Cheers Dan
it's always something simple
one test is worth a thousand guesses
95 Chev Suburban 6.5 w performance mods
91 Mercedes 300D 603.960 6cyl 3L
87 Mercedes 190D 2.5 Turbo
2000 Jetta TDI
76 Onan  MDJF 15Kw genset
5.5 years and counting on B100

Reply #7November 11, 2007, 07:39:33 am

pariah

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wow
« Reply #7 on: November 11, 2007, 07:39:33 am »
umm... good questions... the mk1 has metal lines that run the length of the car so there is only flexable lines like 1 ft on either side .... they are fine on the vaccum

Reply #8November 11, 2007, 11:42:44 am

jtanguay

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Replace leaking fuel lines on MK2 with viton?
« Reply #8 on: November 11, 2007, 11:42:44 am »
what are good hoses for the cloth return lines?  mine keep leaking and its pissing me off... i'm not using biodiesel or anything either!  anyone have a good and possibly cheap solution that will withstand ulsd and bio?

thanks


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Reply #9November 12, 2007, 02:15:30 pm

MikeyT

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Replace leaking fuel lines on MK2 with viton?
« Reply #9 on: November 12, 2007, 02:15:30 pm »
I've used the polyethelene tubing and fittings (push-on) from Lowes plumbing section for over a year, they are cheap and are holding up fine, no vacuum or pressure leaks. 3/8 OD for the feed and 1/4 OD for the return, ran them in exactly the same position as the original lines. Gates brand fuel rated 1/8 rubber line in place of the expensive VW cloth covered line also works for me, you should be able to get this at any real auto parts store at around .50 per ft.

Reply #10November 12, 2007, 06:58:32 pm

bigblockchev

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lines
« Reply #10 on: November 12, 2007, 06:58:32 pm »
JT that is what I used the viton for, the return lines. You only need a short section maybe 18" or so to do them all. Cheers Dan
it's always something simple
one test is worth a thousand guesses
95 Chev Suburban 6.5 w performance mods
91 Mercedes 300D 603.960 6cyl 3L
87 Mercedes 190D 2.5 Turbo
2000 Jetta TDI
76 Onan  MDJF 15Kw genset
5.5 years and counting on B100