Help replacing fuel line.

built4sound · 07-02-2011, 11:17 AM

Well the time my car has sat in the garage sleeping is definitely costing me some extra projects. I have a leak in the gas line from the output side of the fuel pump.

Problem is trying to replace it. The end that goes to the rear of the car slides into a plastic tube. The tube is not stationary making it very difficult to push the hose on. The tube appears to go through the tunnel and I cant seem to find a way to hold it in place to install the new gas line.

Any suggestions?

BoxsterGT · 07-02-2011, 12:56 PM

Is it the rubber hose that is crimped to the plastic tube in the tunnel?

Its very hard to repair this properly, as it is the pressure line.

Available from our host as original plastic, or go to stainless tube w flared ends.

Search for lots of threads on this subject.

I have crimp fittings & hose if you want to go the stainless route.

Len

dipso · 07-02-2011, 02:34 PM

I think the plastic tube runs through the tunnel. At either end regular fuel line is used to make bends and connections. On mine I just used fuel line and a couple of hose clamps. I have plastic lines through the tunnel and rubber fuel line to the tank in the front, and to the carbs in the back.

I am pretty sure the plastic line fit into the fuel line. I remember I had to join 2 fuel lines and used a piece of that plastic line as a coupler, with some clamps.

built4sound · 07-02-2011, 06:22 PM

Yea, you both describe it perfectly. The hose I took off was just pushed on with a hose clamp. I guess I need to find the back side if the plastic pipe to figure out how to hold it in place. Or snake another line through the tunnel.

built4sound · 07-02-2011, 06:25 PM

Quote:

Originally Posted by dipso

I remember I had to join 2 fuel lines and used a piece of that plastic line as a coupler, with some clamps.

Same here, the output of the pump is a much smaller size than the tube running through the tunnel. At least in my case.

sundevil64 · sundevil64's Garage

There should be two flats that you can put a wrench on. I just stripped an 86 cab that I took the fuel lines off of. I which I had taken a pic for ya. I think it was an 11mm wrench?

dipso · 07-03-2011, 06:18 AM

I didn't have any troubles making my connections. I don't remember the plastic hose being loose or hard to grab..
I would be a little concerned just snaking another line through the tunnel. That is where your shift rod is, and any constant rubbing on the fuel line would worry me. I wouldn't want to wear a hole or weak spot into it.

I think the existing plastic fuel line is clamped to the sides of the tunnel to hold it in a safe place. There should be 2. A supply and a return.

I'm not sure which end of the car you are talking about, the front or the rear, I guess it depends on where your fuel pump is located. Mine is in the front in the smugglers box.
What you might want to do is open the tunnel cover in the rear and check the tightness of the securing clamps and also pull your floorboard behind the pedal cluster and look into the tunnel there as well.

From both those ends, you should be able to secure the existing line well enough to push on your fuel line from under the car, from either end.

BoxsterGT · 07:43 AM

The factory semi-rigid plastic or Nylon tube that runs through the tunnel uses a "insert once-only" type of barbed TUBE fitting. I doubt if you can repair this in place. It requires cutting back to a new section of tube and takes a great deal of mechanical force to insert the fitting. This is usually done on a bench with a vise & special tools.

The flexible rubber hose portion up at the front of the car can be replaced w less effort, as it has a different type of barbed HOSE fitting.

If you are using carbs with a low (5-8 psi) pressure pump, it will accept hose clamps.

However, if you are using your original fuel injection, w 50-60 psi minimum pressures, you really need the higher capacity of crimped fittings.

The factory plastic or nylon lines are still available from our host. You can also go with ss tube w flared fittings like many of us have done.

Len

built4sound · 07-04-2011, 10:23 AM

OK, I got it connected. Found access to the other side from the inside of the car. With a second person I was able to get the new line over the plastic one pretty far and It doesn't leak anymore. I think now that I can move the car I will probably replace the rest of the lines and possibly that tube. The tube certainly doesn't have anything on the end to assure I good seal and all the lines look pretty crusty.
Thank you all for your help.

BoxsterGT · 07-04-2011, 04:17 PM

I am curious, what do you mean by getting the "new line over the plastic one"?

Can you post a photo? This does not sound like the factory method or a very safe one either. (Safe being the key word here.)

Len

built4sound · 07-05-2011, 05:12 AM

Quote:

Originally Posted by BoxsterGT

I am curious, what do you mean by getting the "new line over the plastic one"?

Can you post a photo? This does not sound like the factory method or a very safe one either. (Safe being the key word here.)

Len

I wish I took a pic before I put it back together. I agree that it doesn't seem to safe. I just replaced the line in the fashion it was installed previously. The tube ran through the firewall through a grommet and the short gas line was pushed over it with a hose clamp. Based on your previous post it sounds like the previous owner may have done a little "modification" here.

dshepp806 · dshepp806's Garage

I hope to get my girl on the rack tomorrow and snap some pics of my Wrench's approach to this repair...same kind of thing where the leak was external to the tunnel...went ahead and replaced all things under there, to include a perfectly working 1989 fuel pump...

I'll post 'em tomorrow. As others have noted regarding external tunnel repairs: there is a "not-so-safe" way of repairing this and a "safe" way".

Best!

Doyle

gtBen · 11:48 AM

Hej
Here is a pic from the rear end, it’s the same there with one line just pushed over another and a hose clamp.
I’m restoring my -74 now and I don’t think I will touch the rubber fuel lines in the tunnel! they are NLA from Porsche and what to use instead that is safe?

Bengt

BoxsterGT · 09:27 AM

Many of us have used SS seamless tube available in 8 or 10mm, with a flare nut to connect to new Cohline hoses.

If you cannot find this in Europe, I can make & ship them to you.

Look for a posting by Shaun 84 Targa. He has just completed a 3.2 swap into his 73 using this same method for fuel lines.

Len

BoxsterGT · 10-02-2011, 09:33 AM

gtBen-

Just wondering how you resolved your fuel line problem.

JeremyD replaced the Nylon lines on his 74, and he is very glad he did. The plastic gets brittle over time, and will split & crack.

Len

gtBen · 10-06-2011, 11:32 AM

Hej

Quote:

Originally Posted by BoxsterGT

gtBen-
Just wondering how you resolved your fuel line problem.
JeremyD replaced the Nylon lines on his 74, and he is very glad he did. The plastic gets brittle over time, and will split & crack.
Len

I haven’t done anything to them yet. But I know that I for sure have changed my mind and will now replace the nylon lines with ???

Bengt

steely · 10-06-2011, 01:25 PM

Quote:

Originally Posted by gtBen

Hej

I haven’t done anything to them yet. But I know that I for sure have changed my mind and will now replace the nylon lines with ???

Bengt

I think Jeremy used steel and may have posted about it.
I bought originals and will be replacing the tunnel lines this winter.