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Fri Mar 01, 2013 3:40 pm

I need to convert the size of the fuel line. The thing is that the tube that goes out the tunnel is a bit bigger than the fuel hose I need to use so the only way I can think of is to use a kind of converter from the tube to the hose?
I need to use a 1/4 hose and the tube looks 1/2. Anyone with the same problem? Or any ideas to make this safe?

Fri Mar 01, 2013 4:10 pm

Use the right size fuel hose. It's all metric on the VW, there's no 1/4 in. tubes anywhere. Any VW parts place,
and many general auto parts vendors will have the correct size.

Fri Mar 01, 2013 4:20 pm

A '76 has a 7mm ID fuel line. Are you changing it because it is carbed now?

Fri Mar 01, 2013 4:54 pm

Yes, I have this problem. It was a F.I. and now has a carb engine. So the tube that goes out from the tunnel is bigger than all the fuel hoses I need to install from that tube that goes out the tunnel and then to the fuel pump and to the carb so I really dont know how to convert that tube into a smaller hose. I will add some photos in here to show the problem.

Fri Mar 01, 2013 5:15 pm

I pulled this image off of WW Graingers Web site, but these are available in many sizes from many places.

http://www.grainger.com/Grainger/PARKER-Union-Reducer-2GUF7?Pid=search

Dave

Fri Mar 01, 2013 7:51 pm

Thank You for the image and the link!

Fri Mar 01, 2013 9:32 pm

This question got me thinking. Rather than a hose adapter, why not "kill two birds with one stone"... get a fuel filter with 3/8" NPT threaded ends and put two different sized barbed tips on each end. One end 5mm for the hose to the fuel pump, the other end 7mm for the tube coming from the tank. Place the filter down next to the transmission and it serves as the filter and the adapter.

I found the following on SummitRacing's site and aircooled.net:

Sat Mar 02, 2013 2:56 am

Ashman- those are sweet filters, but man are they expensive!

Sat Mar 02, 2013 4:48 am

ashman40 wrote: This question got me thinking. Rather than a hose adapter, why not "kill two birds with one stone"... get a fuel filter with 3/8" NPT threaded ends and put two different sized barbed tips on each end. One end 5mm for the hose to the fuel pump, the other end 7mm for the tube coming from the tank. Place the filter down next to the transmission and it serves as the filter and the adapter.

I found the following on SummitRacing's site and aircooled.net:

Agree -The less connections the better!Less places to form a leak!!

Sat Mar 02, 2013 5:17 am

I found a Mr Gasket filter that I know will raise some criticisms since it is the glass type that some dislike :(

It comes with 1/4" and 5/16" filltings which are close to the 5mm and 7mm hose sizes. You will want to use hose clamps and cable tie this filter to the clutch cable or a bracket so it doesn't move around.

Sat Mar 02, 2013 5:47 am

So, throwing out the expensive filters... using a male and female NPT barbed fitting connected together... one 5mm (1/4") and the other 7mm (5/16") with hose clamps and teflon tape you can create a custom hose adpater.

Go check out your nearby hardware or home improvement center and you can probably pick of these two pieces for less than $10.

Sat Mar 02, 2013 5:58 am

ashman40 wrote: I found a Mr Gasket filter that I know will raise some criticisms since it is the glass type that some dislike :(

It comes with 1/4" and 5/16" filltings which are close to the 5mm and 7mm hose sizes. You will want to use hose clamps and cable tie this filter to the clutch cable or a bracket so it doesn't move around.
I'm not a glass filter hater, I ran one for almost 20 years on my convertible, and that same filter is now on my buggy for the past 3 years. I just DO NOT TRUST those plastic screw on nipples on the new filters.

I sure do like the idea of different size hose barbs, but the plastic has me concerned.

Sat Mar 02, 2013 8:29 am

ashman40 wrote: I found a Mr Gasket filter that I know will raise some criticisms since it is the glass type that some dislike :(

It comes with 1/4" and 5/16" filltings which are close to the 5mm and 7mm hose sizes. You will want to use hose clamps and cable tie this filter to the clutch cable or a bracket so it doesn't move around.

I do NOT like plastic fittings on that filter, that's for sure.

I also had a similar filter on my 1835/Weber engine back in the 1970s, every few months would get a little brown filter-element particle stuck in one of the small idle jets. In other words, the filter was generating particles !!!

Also, that element actually separated water out of the gasoline, could see the lower level of water trapped inside the clear element, so I'd drain it periodically. So that type sure didn't work for me.

Now I use an all-metal fuel filter that has hose barbs, from AutoZone, Deutsch #FF403.

Tue Jun 03, 2014 1:41 pm

ashman40 wrote: This question got me thinking. Rather than a hose adapter, why not "kill two birds with one stone"... get a fuel filter with 3/8" NPT threaded ends and put two different sized barbed tips on each end. One end 5mm for the hose to the fuel pump, the other end 7mm for the tube coming from the tank. Place the filter down next to the transmission and it serves as the filter and the adapter.

I found the following on SummitRacing's site and aircooled.net:

Nice. I too am going the NPT route. Need to step up from 5mm to 7mm for my webers, so I'm going with a regulator with npt threads on all ends. Question- did you have to seal the thread to prevent leaking? If so what did you use? I've heard everything from tape to this stuff : http://www.jamestowndistributors.com/userportal/sh...+3+Sealant

Tue Jun 03, 2014 2:31 pm

Call me crazy, but you COULD just use the stock style filter like this one:
http://www.mamotorworks.com/VW/product/fuel-filter-in-line-universal-clear-each_300785

You should be able to just use the 7mm hose from the tunnel line to one side and the 5.5mm from the other side to the carb...these filters all have a stepped up size fitting if you just push the hose on further. Boom, adapter for $3.

Tue Jun 03, 2014 2:45 pm

negativearth wrote: Call me crazy, but you COULD just use the stock style filter like this one:
http://www.mamotorworks.com/VW/product/fuel-filter-in-line-universal-clear-each_300785

You should be able to just use the 7mm hose from the tunnel line to one side and the 5.5mm from the other side to the carb...these filters all have a stepped up size fitting if you just push the hose on further. Boom, adapter for $3.

I considered that- but I am leery of having fuel filter in engine bay, and it would have to be placed after the fuel pump. Here is the fuel line setup I'm thinking: filter under tank (like stock),leave existing line in the tunnel (no evidence of leaking), then new rubber hose that connects the tunnel line to the steel firewall line (with 2nd filter), then new rubber line to fuel pump, then to regulator. Up to this point its all 5mm. Its at the regulator that I'd step up from 5mm to 7mm using the NPT barbs. I did consider a 7mm electric fuel pump under the tank but that opens up a whole new can of worms...

Tue Jun 03, 2014 2:53 pm

I just use one all metal filter, mounted down by the transaxle...I buy them at NAPA for just a few bucks and change it once a year...two filters are unnecessary. 8)

Tue Jun 03, 2014 2:58 pm

tom_f wrote: negativearth wrote: Call me crazy, but you COULD just use the stock style filter like this one:
http://www.mamotorworks.com/VW/product/fuel-filter-in-line-universal-clear-each_300785

You should be able to just use the 7mm hose from the tunnel line to one side and the 5.5mm from the other side to the carb...these filters all have a stepped up size fitting if you just push the hose on further. Boom, adapter for $3.

I considered that- but I am leery of having fuel filter in engine bay, and it would have to be placed after the fuel pump. Here is the fuel line setup I'm thinking: filter under tank (like stock),leave existing line in the tunnel (no evidence of leaking), then new rubber hose that connects the tunnel line to the steel firewall line (with 2nd filter), then new rubber line to fuel pump, then to regulator. Up to this point its all 5mm. Its at the regulator that I'd step up from 5mm to 7mm using the NPT barbs. I did consider a 7mm electric fuel pump under the tank but that opens up a whole new can of worms...

The way I was taught (when I worked at a shop) was that the factory method was to put a fuel filter in the engine bay like this between the pump and carb. They have done it this way for 35+ years:

I was mainly speaking to the starter of this thread, 76sb, about how to solve his problem. He could just install the filter shortly after the line exits the tunnel, above the transmission, and do the changeover there. Something similar could be done in your situation or just about any, as long as the filter is not in danger of being caught in moving parts or too close to a heat source, it can be placed almost anywhere.

Tue Jun 03, 2014 3:21 pm

negativearth wrote: tom_f wrote: negativearth wrote: Call me crazy, but you COULD just use the stock style filter like this one:
http://www.mamotorworks.com/VW/product/fuel-filter-in-line-universal-clear-each_300785

You should be able to just use the 7mm hose from the tunnel line to one side and the 5.5mm from the other side to the carb...these filters all have a stepped up size fitting if you just push the hose on further. Boom, adapter for $3.

I considered that- but I am leery of having fuel filter in engine bay, and it would have to be placed after the fuel pump. Here is the fuel line setup I'm thinking: filter under tank (like stock),leave existing line in the tunnel (no evidence of leaking), then new rubber hose that connects the tunnel line to the steel firewall line (with 2nd filter), then new rubber line to fuel pump, then to regulator. Up to this point its all 5mm. Its at the regulator that I'd step up from 5mm to 7mm using the NPT barbs. I did consider a 7mm electric fuel pump under the tank but that opens up a whole new can of worms...

The way I was taught (when I worked at a shop) was that the factory method was to put a fuel filter in the engine bay like this between the pump and carb. They have done it this way for 35+ years:

I was mainly speaking to the starter of this thread, 76sb, about how to solve his problem. He could just install the filter shortly after the line exits the tunnel, above the transmission, and do the changeover there. Something similar could be done in your situation or just about any, as long as the filter is not in danger of being caught in moving parts or too close to a heat source, it can be placed almost anywhere.

They didn't come with gas filters from the factory. Engine bay is not a good place to install one either. Especially a plastic one

.

Tue Jun 03, 2014 3:28 pm

birddog1 wrote:

They didn't come with gas filters from the factory. Engine bay is not a good place to install one either. Especially a plastic one

.
Well, like I said, that was just the way I was taught. I didn't know what the actual factory setup was, though I have additionally put one under the tank if the tank was exceptionally dirty. Engine bay filter placement may just be a tradition of the place I worked, but I assure you they have been doing it this way for a long time and never had an issue. Just something to consider if you're in need of hose size adaption in or near the engine bay as some on this thread have indicated.