Itinerant Air-Cooled

I am planning the replacement of my fuel lines and have several questions:
1) What is the general take on removing the firewall with the engine in? I thought I'd read about it here, but can't seem to locate the thread.
2) My line coming from my tank is 5.5mm and is joined to a small piece of 7mm just before the pump. Normal? should the nipple from the tank be for 5.5 or 7? Mine is clearly 5.5.
3) The above mentioned line (2) goes up and over the starter. Normal? Is there an alternate route?maybe up against the frame and under the starter?
4) The line leaving the pump wraps around and over the starter. Normal? Another route ok?
5) As I was removing the line leaving the pump the little brass tube popped off. What is the fix for this?
6) What is the little piece of line that comes out of the bottom of the pump, runs directly into the tin, but does not link to anything?

Thanks in advance for your responses. I drove buses for years as kid and did just about everything wrong and by rights I should probably be dead for some of the assanine jerry-rigging and shortcuts I pulled off. My goal is to start doing things right.

FYI- I have not hit my Bently yet for any of these answers as I came in from draining the tank, washed up, and am laying in bed typing this... I will look tomorrow.

jimbear wrote:I am planning the replacement of my fuel lines and have several questions:
1) What is the general take on removing the firewall with the engine in? I thought I'd read about it here, but can't seem to locate the thread.
2) My line coming from my tank is 5.5mm and is joined to a small piece of 7mm just before the pump. Normal? should the nipple from the tank be for 5.5 or 7? Mine is clearly 5.5.
3) The above mentioned line (2) goes up and over the starter. Normal? Is there an alternate route?maybe up against the frame and under the starter?
4) The line leaving the pump wraps around and over the starter. Normal? Another route ok?
5) As I was removing the line leaving the pump the little brass tube popped off. What is the fix for this?
6) What is the little piece of line that comes out of the bottom of the pump, runs directly into the tin, but does not link to anything?

Thanks in advance for your responses. I drove buses for years as kid and did just about everything wrong and by rights I should probably be dead for some of the assanine jerry-rigging and shortcuts I pulled off. My goal is to start doing things right.

FYI- I have not hit my Bently yet for any of these answers as I came in from draining the tank, washed up, and am laying in bed typing this... I will look tomorrow.

I had a 73 with the mechanical fuel pump like yours. My memory is not what it used to be, but I recall the incoming fuel line almost draped over the transmission. I don't think the route matters too much. It was 7mm from the tank to the pump, then smaller on the way out of the pump. I don't recall the line leaving the pump going anywhere but straight up to the firewall close to the bell housing. The fuel line definitely needs to be protected by something as it goes through the firewall. If you don't have the correct grommet, then use something wrapped around the fuel line, like an old piece of brake booster line.

To replace the brass tube, you need to knurl or rough up the part that inserts into the pump. That will give a little more interference fit. Back it up with a wire tied around the hose clamp once you install the fuel line. The little hose that runs into a hole in the tin is a vent - it just needs to be open and able to breathe.

When you say firewall, are you talking about the fuel tank cover? You can get it out without removing the engine, but you have to strip everything off the top of the engine.

Hope that helps some. Others may have a more recent and memorable experience they can relate.

Tim

I had a hose on my 72 that went nowhere. I was told it was a vent (?)

Another good replacement fix for the fuel line grommet thru the firewall is to use some lamp socket fixture pieces rigged so the fuel line goes thru it instead of the firewall. It requires no future replacement once done.

The line that goes no where is just that a vent. If the diaphram ruptures the fuel will go out the vent and onto the ground. Unlike the T-1 pump which will flood your crankcse with fuel.