Fuel Line replacement

[DaveFL]

When I did my inspection port for the intank fuel pump, I had to lift the carpet(didn't want to cut) so I got to see the structure similar to what your first picture shows. I didn't remove the plastic cover to reveal pipes or the hole but on the street side they didn't use plastic only a thin plywood cover box to hold carpet, under that was the gapping 4x8 hole for the 2 inch pipe, but it was sealed by carpet and caulk.
I did smell gas last year when I filled the fuel tank, but it went away fast, so seeing your setup, I should have taken that plastic cover off to reveal the gas overflow and vent tube, good news is I can do it next time I smell gas.
My solution to replace fuel lines would utilize the access port I cut in the floor maybe make it bigger for an easier job, use the old fuel lines to pull new or if they aren't free, route new ones by a different route coming out of the front top area of the tank and take same rubber to the side rail install filter and use steel to the front, change over to rubber to the motor. about 5 joints(each a possible future leak so visible and accessable for future inspection and repair.

[Keyair]

Thanks Dave.
My discovery was kinda a shocker, because I had already replaced the filler pipe below the floor, yet still could smell the gas...

I think its an important one to share here, and I hope nobody thinks I am a thread hijacker!

I will be replacing these 2 pipes, and making a plate to seal that hole in the floor.
Need to do some work on the ABS cover too.
Its really flimsy. I am thinking to solvent glue some strips of ABS onto the flanges, and top edge to stiffen it, and that will allow the sealant to hold and seal better.

The pipe over the grey tank has got to be replaced... Its high in my mind that around the Wheelarch on that side is where I smell gas outside.
I am thinking same as you, and will find some SS line, so its done right. I am no way dropping the grey tank unless I have to. If I need to bend it or reroute it I will.

[choctawmel]

I've had luck with fiberglass cloth and PVC cement. Clean the surface, gob with PVC cement then lay the cloth in it. Keep adding cement and more cloth ever time it drys until you're happy (or stoned).
In two weeks I go on a short 230 mile round trip. I got 316 miles on this tank now, so I need to buy 6 gallon of gas to get home on fumes. I have put 76 gallon in, but it was cutting out the last 4-5 miles to the gas station. Better plan on 10-16 gallon to be sure. I can't push it or can I turn/stop it without the engine running.

[Keyair]

I make a slurry of MEK and ABS bits... works great.

Further to the filler pipe saga... I was woking on the Utilities compartment, pulled the sewer pipe storage out, and there it was...


Looking rearward...

[HHaase]

Going to chime in a bit on this one, as I'm seeing a few things that I'm not comfortable with in the photos and discussion related to fuel lines.

One is that I'm not seeing mention of pressure ratings, and it's a big problem popping up these days. If you're running any kind of in-tank or electric pump, you really want to make sure the line is rated for the pressure. Old mechanical fuel pumps running into carburetors ran pressure in the single digits, and even then was mostly hard-line from the pump to the carb. Modern EFI pumps in-tank are generally running 30-35psi, with some oddball setups much higher than that. IIRC the old GM TBI systems are around 15psi or so.

People are talking about ethanol compatability, which is good to see, E85 will destroy your fuel lines in a hurry if you accidentally put it into a non-compliant vehicle.

I have to say too that I am NOT a fan of those stainless worm clamps, particularly in a high pressure area. Over time it causes the fuel line to work harden and shrink, as the rubber expands/contracts, causing leaks about two or three years down the road. They may be a pain in the ass, but those squeeze style factory clamps really are better in the long run (but still get new clamps). And, again, if it's a high pressure EFI setup, you really need to get proper EFI clamps or you will eventually have lines blowing off the barbed fittings. Oedicker "ear" style crimp clamps are also very good for that type of installation.

-Hans

[Keyair]

Very good points Hans, and thanks for the info on the clamps!
Can you be more specific on whattype of clamp is best?

I spent a little time crawling about, and looking at the Grey tank hard pipe.... its not gonna be fun, but I have to do it...

I noticed something else yesterday.....
On the Chassis hard pipe, above the axle... the worm clamps on the junction to the rubber pipes, are pointing UP!
That can only mean that the last time the were tightened... it was done from above... meaning when it was a bare Chassis!
Original, 27 year old rubber piping... not a good thought!

[HHaase]

Originally Posted by Keyair

Very good points Hans, and thanks for the info on the clamps!
Can you be more specific on whattype of clamp is best?

I spent a little time crawling about, and looking at the Grey tank hard pipe.... its not gonna be fun, but I have to do it...

I noticed something else yesterday.....
On the Chassis hard pipe, above the axle... the worm clamps on the junction to the rubber pipes... are pointing UP.. That can only mean that the last time the were tightened... it was done from above... meaning when it was a bare Chassis... meaning its original, 27 year old rubber piping... not a good thought!

Lots of good options out there. When I did the EFI conversion in my CJ-7 I used "double ear" clamps, but you do need a special tool to install them and removal isn't easy.
double ear clamp,double ear clip manufacturer and double ear clamp,double ear clip supplier--China Ningbo Kingsun Hose Clamp Factory.

A quick google search for "Fuel Injection Hose Clamps" turns up a lot of options. Here's what a common type looks like
Amazon.com: 10 pack Breeze FI5PB Mini G Fuel Injection Hose Clamp Effective Diameter Range: 7/16" - 39/64" (12.5mm - 15.5mm) for 5/16" Hose: Home Improvement

The important thing is that it isn't totally rigid, and has some type of spring action to it, that way it swells and contracts with the hose and gives a constant pressure. This prevents it from work hardening the rubber over time. Most people see it happen on radiator hoses more than fuel line, when they use the worm drive clamps, but the effect is the same.

-Hans

[choctawmel]

Keyair, Glad my fill/vent is all under floor. Replace them in a RV park in Texas years ago. Found gas rated fill hose at the NAPA down the street.

On fuel line pressure: If at all possible I'm using SAE 30R9 hose. I just notice the 1/2 I replaced is SAE 30R6. The min burst pressure is still 175 PSI (SAE 30R9 is 500PSI) and that line is regulated at 8 PSI up to the EFI pump which is 18PSI then the R9 to the throttle body. The last hose was still keeping the gas in after 25 year. In another 25 years I'm sure either the cops or my kid will take my keys away.

[crazeevw]

Wondering, with the fuel lines in our Classic motorhomes really not designed for 10% ethanol blend gasoline, any thoughts as to maybe that's some of the problems with our generators? Maybe I need to get the filters all switched out and see if I can get it started. I did put some "Sea Foam" additive in my fuel tank to see if it wouldn't help with some of the ethanol problems. Was going to use StaBil, but Sea Foam was recommended. Any thoughts?
Thanks, Derek

[DaveFL]

Derek I used seafoam but in a different way, I opened the line just below the filter, took off the filter and was able to put it in the line, reattached the filter, after 3 tries and a day of sitting it started. I took the carb bowl off and cleaned out crud, sqirted carb cleaner in all opening. When I read the directions of seafoam, you would have to use a gallon of it for a tankful of fuel.

[Keyair]

I love Seafoam...
I have heard people call it snake oil, but I recently cured a misfiring Nissan with it... Injector was, I assume part blocked... a 1/4 tank of fuel and a whole quart of Seafoam, and it was cured... and 2k miles later still running great.

I suggest, as the the genset has its own fuel pump, putting a gallon of gas, in a can with maybe half the can of Seafoam... detach the fuel feel line and feed it from the can... Run the whole gallon thru, and it should help.

[navyspook]

My Gen Set problem was much more simple, so far. Rodents made a nice home on top of the gas tank and chewd thru the gen fuel supply line. Thankfully, not the main supply line to the carb. Sooo dropping the tank and replacing as much rubber as I can get to, with the type suggested here, as well as the filters.

Is there anything I can put on the lines, besides a cat, that will make it distasteful to mice. Seems like a business opportunity...

[crazeevw]

No idea about a cat on top of your fuel tank, but my Mom throws out red pepper on her landscaping to get rid of cats.......
Honestly, before you re-install the fuel tank, maybe find some of the pepper spray that letter carriers use. I know that it's only mineral oil and cayenne pepper. No idea what mineral oil will do to rubber fuel lines though. Just don't get any of it on yourself, take it from me, that stuff burns a day later, after washing myself with Go-Jo, it just doesn't go away that easily.....
Derek

[vswingfield]

Originally Posted by navyspook

...
Is there anything I can put on the lines, besides a cat, that will make it distasteful to mice. Seems like a business opportunity...

Snakes work even better than cats.

They even keep other things besides mice away.

[navyspook]

Bingo, the pepper spray might work, not sprayed on the hoses, but on the tank to keep their feet off. I know what you mean about removing it...accidently set my wife's spray off in her purse...not pretty. The mouse was probably the same vermin that ate my Chevy pick-up's air filter.

I like the snake idea also, but you're right...it would also keep my wife away. Ya got snakes, ya ain't mice.

[Keyair]

When its all said and done, just the plain simple snap style mousetrap works...
$2 a piece for the larger one. Cheap enough to throw the whole thing away if ya dont want to spring the carcass.
Bait it with Peanut Butter unset for a few days, then set it...
Got the 2lb Rat that was eating our Tomatoes last week... SNAP... Dead, quick, simple and gone...

[choctawmel]

Well I did it! Figured it I put 6 gallon in on the way to the lake this last weekend I'd be empty when I got home. I put 12 gallon in to be safe. Got a total of 535 miles, got home and pumped out 16 gallon. The tank is larger than 80 gallon or I got better mileage the 320 miles I drove w/o the toad. Pulled the fill tubes off.

Dropped that tank.

Had to grind the heads off the clamp bolts that held the tubing over the gray water tank to get them out of the way. Unbolted the Generator tube and was able to force it back 6 inches to get to the hose clamp behind the gray water tank on it. I do not understand why Airstream put such short tubes for the return, vent, and generator lines leaving then to terminate out of sight behind the gray water tank. Removed and replaced the return steel line with larger line from the front to the just before the gray water tank to accommodate the EFI. Of course I had to buy myself a high dollar flaring tool to flare the steel lines (I've been wanting to get one for years)

Put all new clamps and hoses, jacked that tank back into place. Poured (and splat) 10 of the 16 gallon I took out back in the tank.
Time to start it and leak check my handy work. Got her started and the fuel pressure gauge pegged and the engine rans ruff, smoked like crazy. The neighbor came running thinking the barn was on fire. Well something is not right. I drop the tank and I got the return and vent hoses under the top tank support. Got that right and she runs just like she should. Now all I need is someones credit card and got fill-er-up to the tune of $250!
OUCH!

[Keyair]

Awesome...
I will be at this soon too!