Fuel Line Leak

[Richie G]

That's probably the way to go.  What specifically needs to come out and in what order if any?  It seems engine side isn't much if anything at all.  What about in the tunnel?  It seems you have enough room to do it undisturbed about as far back as resonator but I couldn't see much beyond that with my limited clearance.  Maybe if I had another set of rhino ramps I could get all four tires up and do it?

Edited July 1, 2023 by Richie G
fix word

[Racer X]

I feel for you guys who don't have the years of experience and training it really takes to effectively make proper repairs. I'll try to offer some insight and help that will get you moving in the right direction.

First, those cheap arse jacks at Harbor Freight are junk, and I don't know who is selling, if anyone, a good quality jack. Mine are both fairly old, manufactured in the early 1980s. Even with that, I just had a local shop rebuild mine.

Two of my jacks:

I also have decent quality jackstands, in a couple of sizes depending on what I need to support, and like the jacks, no one seems to sell them anymore.

Additionally, I have a large, well equipped shop with enough tools to make Tim the Toolman Taylor jealous, and a lift, but not all the work I do can be done on a lift. For instance, I have been doing a lot of work on a 1995 F150 I picked up from my oldest grandson a few years back. It is too big for my lift, so everything I do that requires clear access underneath it, is done on jackstands. For instance, the fuel tanks were rusted and leaking, and new ones were available, so a couple years ago I swapped them out. And while I had it in the shop, I decided to do a brake job. What a can of worms. By the time I was done, I replaced everything on the brake system but the brake pedal, including all the hard lines. I also replaced all of the fuel lines. Snaking them along the frame rails, around the crossmembers, and wiring, and transmission, and transfer case, and engine and exhaust was difficult, but not impossible.

I chose stainless steel.

Which brings me to comment about your leaky fuel line.

The hard lines on your Z are likely original to the car.

The repair by the PO, and the problems you are having now, cause me to comment that you really should replace the entire line, from the tank to the engine bay. Classic Tube offers them, either in mild steel, or stainless steel. The previous repair may have been well intended but was poorly executed. The hose and clamps you have put on is sketchy, and I would not want to read a post by you that relates a fire that has destroyed your Z.  Any fuel leak is dangerous. Patcon mentioned that it is the vapor of fuel that is the dangerous thing, and he is correct. But a puddle of gasoline will quickly become vapor, especially in the 100 degree heat of Sacramento. Don't play Russian roulette with your car.

I highly recommend the stainless. It doesn't cost that much more than the mild steel and will outlast the car.

And you can replace the lines without a lift, just the car on stands, and without pulling the engine and transmission. It will be a bit tricky, but it can be done. 

 

I bought the entire set of hard lines for my 72 240Z from Classic Tube, in stainless, for the fuel, clutch and brakes, and will be replacing them, soon myself. I've examined the car and feel that I could also do the job with the engine and transmission in the car, on jackstands, but I am also pulling them because the engine is tired and needs an overhaul. If I wasn't already pulling the drivetrain, I would definitely do it with them in, as I am too lazy to bother doing work I don't need to do.

 

I also need to comment on the type of end the lines have. It is not a compression fitting; it is an inverted flare, and seals where the flared end of the tubing seats on the inverted flare inside the fitting and the clamping pressure exerted by the nut is what keeps it from leaking. These fittings do not require a huge amount of torque to make the seal. There are tools available to make the ends up, but if you get the lines from Classic Tube, they are already done, you simply remove your old stuff, put the new stuff on the car, and make the connections. And get a set of flare nut wrenches. Using open end wrenches will collapse the barrel nuts on inverted flare fittings, and round the wrench flats off so the only tool that will turn them is a vice grip.

 

While I'm on the subject of tools, buy quality tools. They will cost more, but it goes like this: Buy quality (read expensive) tools, cuss them once. Buy cheap tools, cuss them every time you use them. I have tools that belonged to my grandfather, and my father, as well as tools that I have collected over a lifetime of working on stuff. Craftsman (from when they were good tools), Snap-On, MAC, K-D, SK, all made in America. I even have the very first socket set my dad gave me for Christmas when I was 10 years old, a 3/8 drive Craftsman set, a ratchet, 3" and 6" extensions, and sockets from 3/8" to 15/16". Never broken, still not worn out, except the ratchet, which Sears gave me a rebuild kit for a couple times over the 56+ years I have had it (although I doubt whoever is selling Craftsman tools these days will honor the lifetime warranty anymore now that Sears is gone). The chrome is worn, but they still get the job done.

 

Edited July 2, 2023 by Racer X

[grannyknot]

2 hours ago, Racer X said:

I feel for you guys who don't have the years of experience and training it really takes to effectively make proper repairs. I'll try to offer some insight and help that will get you moving in the right direction.

First, those cheap arse jacks at Harbor Freight are junk, and I don't know who is selling, if anyone, a good quality jack. Mine are both fairly old, manufactured in the early 1980s. Even with that, I just had a local shop rebuild mine.

 

 

You said it brother!

Good quality jacks can be had on craigslist or kijiji for a 1/3rd the price of new and they will last.

I know a lot of guys like SS brake and fuel lines but they are so hard to work with and difficult to get a good seal without repeated tightening, where as Cunifer brake line can be bent by hand, never rusts, shines up beautifully and you get a good seal every time.

Edited July 2, 2023 by grannyknot

[Patcon]

I believe, buying premade lines is the way to go in your case.

It is probably possible to do with everything still in the tunnel. I would definitely start like that. You might find removing the exhaust or driveshaft makes it easier. Beware of breaking bolts on the exhaust. It will just make more work that is not easy to fix.

Bear in mind, stainless lines can be difficult to seal because they are harder. I suspect steel lines will easily last another 50 years. Longer than most on this forum, including me, will be around...

[Zed Head]

ZCD has stuff.

https://zcardepot.com/collections/fuel/products/fuel-line-pump-to-engine-stainless-steel-280z-1977-78

[Richie G]

Agree with all that was said, and jealous of Racer's tool collection and shop!  I will certainly be doing this in the near future and keep an eye on this section very closely.  I was already looking at the ZCD items and they also have the rubber mounts and clamp downs I'll need.  The few sections I loosened had dry rot rubber and a few even had some give to the clamp but it's tightly down again.  Couple of questions.  I see ZCD has the stock finish or stainless.  I guess I can ask them but if anyone knows is the difference really just the plating and the stock is also stainless?  I was going to get both fuel lines and the vapor line in stock finish but not upsized (slowly starting to add some originality back to the car).  Should I stick with this or get anything upsized?  Also, I see when I did the tank there was a rubber mount for the end of the hard lines.  Is there supposed to be one in the engine bay where the fuel line attaches to the filter?  I don't recall seeing one there and wasn't sure if the end of hard line just came up 90 to meet hose for the filter or PO lost it..

[Racer X]

Regarding the stainless lines. Classic Tube ships the lines in a cardboard box, about 3.5 feet long. Since the longer lines exceed this, they have “shipping bends” which must be straightened out prior to installation. I found it easy to do, following the provided instructions. 

Also, I didn’t find it any more difficult to tighten the ends, using my calibrated from years of experience hands and flare nut wrenches. Classic Tube recommends 15ftlbs of torque. So if you have a crows foot flare nut wrench and a torque wrench, that is the best practice.

Can’t recall if they specify the grade of stainless but I suspect they are using 301, which is malleable enough to not have the work hardening issues of other stainless grades. 
 

And the stainless polishes up mirror shiny for those who want more bling.

 

 

 

[Yarb]

Recently bought a stainless fuel line kit from SSTube. 1/3 of the cost. Good people and they answer the phone. Hand made in house.

[Racer X]

12 hours ago, Richie G said:

 Also, I see when I did the tank there was a rubber mount for the end of the hard lines.  Is there supposed to be one in the engine bay where the fuel line attaches to the filter?  I don't recall seeing one there and wasn't sure if the end of hard line just came up 90 to meet hose for the filter or PO lost it..

On my 72 the fuel line is secured all the way to where it turns up just below the fuel filter at the forward right side of the engine bay.

[Richie G]

Thanks X yes I see the last one before the turn about a few inches.  I just wasn't sure if there was a vertical one on the upside.  May I ask a dumb question?  You're comment about flange wrench

21 hours ago, Racer X said:

I also need to comment on the type of end the lines have. It is not a compression fitting; it is an inverted flare, and seals where the flared end of the tubing seats on the inverted flare inside the fitting and the clamping pressure exerted by the nut is what keeps it from leaking. These fittings do not require a huge amount of torque to make the seal. There are tools available to make the ends up, but if you get the lines from Classic Tube, they are already done, you simply remove your old stuff, put the new stuff on the car, and make the connections. And get a set of flare nut wrenches. Using open end wrenches will collapse the barrel nuts on inverted flare fittings, and round the wrench flats off so the only tool that will turn them is a vice grip.

I was under the impression at each end of a new hard line I would just install the correct rubber hose and clamp?  I'm not exactly sure what else I would be doing or what would be flanged, my current lines just have a hose and clamp from filter to line and from line to tank on both supply and return.

[Racer X]

20 minutes ago, Richie G said:

Thanks X yes I see the last one before the turn about a few inches.  I just wasn't sure if there was a vertical one on the upside.  May I ask a dumb question?  You're comment about flange wrench

I was under the impression at each end of a new hard line I would just install the correct rubber hose and clamp?  I'm not exactly sure what else I would be doing or what would be flanged, my current lines just have a hose and clamp from filter to line and from line to tank on both supply and return.

It is called a flare nut wrench. Found on the brake lines, but not the fuel lines on the carbureted Z cars. 

So yes, for the earlier Z cars a short length of fuel rated hose,    and a couple hose clamps.
 

 

 

[Richie G]

Ah OK thought the PO had really gone nuts there for a moment lol. So brakes need the flare wrench for the various connections. Thanks as always