shadango
Well-Known Member
Does anyone know 100% for certain what size the hose is that transitions from the frame rail fuel line coming from the tank and the line that goes to the fuel filter/pump on a 1980 Volare 6 cylinder?
frame rail gas line to fuel filter/pump line hose size
- Thread starter shadango
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shadango
Well-Known Member
Thanks!
shadango
Well-Known Member
Alright so another couple of dumb questions. The last time I changed out lines like this was on my barracuda 8 or 9 years ago and the system was dry......this is a running car. There are 3 rubber lines at the location I am talking about. The larger one is obviously the main fuel line.....the smaller has a valve of some sort in it and I am assuming its the return line....and the smallest line I assume is vapor recovery. That smallest line is hard.....but also the hardest to get to the top of. The second line is just as difficult but the rubber isnt so bad. And the main fuel line seems to be serviceable though maybe a bit soft....they all appear original to me because they use the crimp style clamps....but the valve that is inline is secured with aftermarket clamps. No idea what size the two smaller hoes are...I am guessing maybe 1/4 for the middle (return) hose...? The vapor hose is small and I am not so worried about that right now.
Now, it occurs to me now that it would have been much easier to mess with these with the engine out....we could have unbolted the steel lines from the frame and fed them back a bit, etc.
But the engine is in and it is what it is,.
When we did the engine I recall some gas coming out of the main fuel line.......we had to plug it to stop the flow.
If we have the front end raised up above the level of the tank, will we be able to pull the main fuel hose out under the car without having niagra falls of gas?
I followed the gas lines to the back and they make a big bend upwards and over to to the top of the tank...seems to me we should be ok if the front end of the car is up and the tank is low? Looking for some "been there done that" tips....
Now, it occurs to me now that it would have been much easier to mess with these with the engine out....we could have unbolted the steel lines from the frame and fed them back a bit, etc.
But the engine is in and it is what it is,.
When we did the engine I recall some gas coming out of the main fuel line.......we had to plug it to stop the flow.
If we have the front end raised up above the level of the tank, will we be able to pull the main fuel hose out under the car without having niagra falls of gas?
I followed the gas lines to the back and they make a big bend upwards and over to to the top of the tank...seems to me we should be ok if the front end of the car is up and the tank is low? Looking for some "been there done that" tips....
volare 77
Well-Known Member
First remove the gas cap to relieve any pressure and put back on. Put on a longer hose to a catch can to get whats in the line. Your going to get some gas but if the front end is up then the gas shouldn`t go uphill. Do you have a pic of the valve? Must be something special for a six or a 1980. My 77 the roll over valve is on the tank but mine is a v8. Maybe somebody with a six has a better idea on the hose routing. I only had one six many years ago. Does the fuel filter have two or three hoses on it?
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shadango
Well-Known Member
The filter has three hoses on it, one hose going to what I believe is the return, which is where the valve do-hickey is.
volare 77
Well-Known Member
ok, I looked in my 77 service manual . I don`t know if 80 is different. The valve that is between the fuel line and the fuel pump is a displacement shut off valve and it is there in case of a frontal accident to shut off fuel flow. here is a pic . I didn`t find anything on the hose sizes. I would think 5/16 and 1/4
shadango
Well-Known Member
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Some pictures of the fuel lines (removed from car) – which should be identical to F-body (note: 2-door car lines are shorter than 4-door or wagons). Fuel supply issue (or is this supposed to happen?)
The fuel hoses/line sizes are as you said:
Main fuel line/hose 5/16”
Fuel return line/hose 1/4”
Fuel vapor line/hose 3/16”
The fuel roll over valve has always been mounted on fuel tanks on FMJ-body cars.
The picture you have, shows an in-line roll-over valve it to be for P, D and C – which is C-body cars.
If this was my car, I would remove that add-in valve and replace it with straight hose.
F-bodies have straight (figuratively speaking) lines/hoses from tank to fuel pump/filter and to charcoal canister. From the filter, it goes straight to carburetor (or back to tank).
The troublesome fuel displacement shut-off valve was used for a very limited time and I’ve only seen a couple of them.
A person can use a 2-line filter and bypass the fuel return hose – but I recommend using the 3-line filter. Doing so has dropped the problem of “vapor lock” down to almost nil on stock vehicles.
I don’t like that picture form ’77 FSM on fuel lines. The C-body roll-over valve and only used for a few weeks (and let me say troublesome, again) displacement shut-off valve is confusing and over complicates the picture.
BudW
The fuel hoses/line sizes are as you said:
Main fuel line/hose 5/16”
Fuel return line/hose 1/4”
Fuel vapor line/hose 3/16”
The fuel roll over valve has always been mounted on fuel tanks on FMJ-body cars.
The picture you have, shows an in-line roll-over valve it to be for P, D and C – which is C-body cars.
If this was my car, I would remove that add-in valve and replace it with straight hose.
F-bodies have straight (figuratively speaking) lines/hoses from tank to fuel pump/filter and to charcoal canister. From the filter, it goes straight to carburetor (or back to tank).
The troublesome fuel displacement shut-off valve was used for a very limited time and I’ve only seen a couple of them.
A person can use a 2-line filter and bypass the fuel return hose – but I recommend using the 3-line filter. Doing so has dropped the problem of “vapor lock” down to almost nil on stock vehicles.
I don’t like that picture form ’77 FSM on fuel lines. The C-body roll-over valve and only used for a few weeks (and let me say troublesome, again) displacement shut-off valve is confusing and over complicates the picture.
BudW
volare 77
Well-Known Member
Not sure what is confusing on the roll over valve. The pic shows PDC cars with the valve in vent line and the RWSXHN cars with it on the tank. Are you saying the PDC didn`t have a roll over valve at all? I have never seen a displacement shut off valve on a car before so that is a new one to me that`s why I wanted to see a pic. Now, my question. My 77 has a two piece fuel line as I assume they all do. Was a valve originally supposed to be where the two lines meet? Seems to be a dumb place for a piece of rubber hose or maybe it just made the install of the fuel line easier.
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PDC models (ie: C-body) did use an in-line roll-over valve.
The Picture is confusing sense it has both shown (C-body and everything else).
Chrysler had a problem with the “Displacement Shut-Off Valve” and quit installing them on cars at assembly and “quietly” removed them from cars as cars came into for service (ie: a silent recall, if you will).
The valve is designed to stop fuel flow in a head-on accident. The problem is they would permanently shut off fuel flow during a heavy braking episode. Also it wouldn’t shut off fuel flow in head-on accidents (or accidents in general) – so idea was scraped.
Only a few cars got them and those that did, most were removed at dealership, without owner’s knowledge.
The web link (top part of post # 10) shows the fuel lines off of the car.
I “suspect” they used two different lines because of cost. They made the long tube using standard 20’ (25’ or whatever length it is) lengths, without cutting, then made the shorter tubes using cut off pieces. My working theory – but nothing to back it up.
The good news is those short sections of hose don’t see much sun or heat, so lasts longer than those hoses underhood.
I’ve never seen an FMJ with any device (other than rubber hoses) between the metal lines (at what I call the hidden location). It is not hidden – but a location most people do not look for.
Someone, after the car was built, installed that device for some reason.
I think it might be a “fuel mileage” part, like adding magnets to fuel lines, or some other kind of un-earthly idea of the sort. Bottom line: You don’t need it.
I recommend to change that section of hose with appropriate length/size and clamp it on. All three lines/hoses are not under much pressure.
BudW
The Picture is confusing sense it has both shown (C-body and everything else).
Chrysler had a problem with the “Displacement Shut-Off Valve” and quit installing them on cars at assembly and “quietly” removed them from cars as cars came into for service (ie: a silent recall, if you will).
The valve is designed to stop fuel flow in a head-on accident. The problem is they would permanently shut off fuel flow during a heavy braking episode. Also it wouldn’t shut off fuel flow in head-on accidents (or accidents in general) – so idea was scraped.
Only a few cars got them and those that did, most were removed at dealership, without owner’s knowledge.
The web link (top part of post # 10) shows the fuel lines off of the car.
I “suspect” they used two different lines because of cost. They made the long tube using standard 20’ (25’ or whatever length it is) lengths, without cutting, then made the shorter tubes using cut off pieces. My working theory – but nothing to back it up.
The good news is those short sections of hose don’t see much sun or heat, so lasts longer than those hoses underhood.
I’ve never seen an FMJ with any device (other than rubber hoses) between the metal lines (at what I call the hidden location). It is not hidden – but a location most people do not look for.
Someone, after the car was built, installed that device for some reason.
I think it might be a “fuel mileage” part, like adding magnets to fuel lines, or some other kind of un-earthly idea of the sort. Bottom line: You don’t need it.
I recommend to change that section of hose with appropriate length/size and clamp it on. All three lines/hoses are not under much pressure.
BudW
shadango
Well-Known Member
Sorry, i fixed the pic.
shadango
Well-Known Member
Had the son swap out the hose today.....
FWIW, the gas flow never stopped. Pretty heavy flow. And that was with the car nose up on ramps....though the whole car was facing slightly downhil to start with...still, the car was front-end-high.....maybe if it had been higher the flow would have stopped....
That said, got the new hose in and no leaks.
Left the vapro and return hose/valve thingie alone for now. I figure the main fuel line is the most important one......the return probably doesnt see much action.....and the vapor one....well....no worries there.
We did , while running it to check for leaks, a knocking noise coming from the smog/air pump.
Hoping that doesnt go while on the way to or from Carlisle this weekend!!!! Figure we can alwasys cut the belt runing the A/C and the smog pump......the A/C dont work anyways and the smog pump is only feeding the head as far as I can tell....the hose has been disconnected from the CAT since we got the car.....
FWIW, the gas flow never stopped. Pretty heavy flow. And that was with the car nose up on ramps....though the whole car was facing slightly downhil to start with...still, the car was front-end-high.....maybe if it had been higher the flow would have stopped....
That said, got the new hose in and no leaks.
Left the vapro and return hose/valve thingie alone for now. I figure the main fuel line is the most important one......the return probably doesnt see much action.....and the vapor one....well....no worries there.
We did , while running it to check for leaks, a knocking noise coming from the smog/air pump.
Hoping that doesnt go while on the way to or from Carlisle this weekend!!!! Figure we can alwasys cut the belt runing the A/C and the smog pump......the A/C dont work anyways and the smog pump is only feeding the head as far as I can tell....the hose has been disconnected from the CAT since we got the car.....
volare 77
Well-Known Member
Glad you got it fixed. BTW, My car is sitting in the garage on jack stands right now (almost level) with the engine out and no fuel is coming out of my fuel line. If the pressure is released I don`t see how gas can go uphill.
shadango
Well-Known Member
I would think the same way but ---- gas cap was off, nose was up hill some......and it was flowing free.......I would say we lost about 2 quarts or a little more......it never showed signs of stopping.
It befuddles me because even if the car is DOWNHILL, the gas line makes a very sharp turn and goes UP in the back then across and then down again.....and the pickup is on the bottom of the tank...cant figure out how it was pushing that fuel.......
AFter it was done I thought we might have been able to blow air into the line and push back the fuel and break the siphon effect if that is what it was.....scratching my head.
But its done. LOL
It befuddles me because even if the car is DOWNHILL, the gas line makes a very sharp turn and goes UP in the back then across and then down again.....and the pickup is on the bottom of the tank...cant figure out how it was pushing that fuel.......
AFter it was done I thought we might have been able to blow air into the line and push back the fuel and break the siphon effect if that is what it was.....scratching my head.
But its done. LOL
I don’t want to comment on what happened here – but I agree, a person does have to remove or loosen the gas cap, at least partially, for there can be 5 – 10 pounds of pressure pushing down on gas, inside of fuel tank. Remove that pressure and it will level out. Otherwise, the pressure will push gasoline quite a distance uphill.
Also, if fuel tank is full, can also have a big influence on when it leaks – even if car is jacked up, in front.
What I generally do, is I will measure the length of hose and cut to length.
Get a 5/16” bolt.
Cut the existing hose roughly in middle and place bolt into rearward section of hose.
Wait a moment for engine side to drain out (there is no way not to lose fuel).
Remove section of engine side hose, and slide on both new hose clamps (but left loose for now).
Remove the tank side hose (with bolt still screwed into it).
Quickly insert new hose on tank side line.
Position and tighten claims after any kinks in hose are removed.
Twisting hose will sometimes smooth out kinks - if present - and you are done.
BudW
Also, if fuel tank is full, can also have a big influence on when it leaks – even if car is jacked up, in front.
What I generally do, is I will measure the length of hose and cut to length.
Get a 5/16” bolt.
Cut the existing hose roughly in middle and place bolt into rearward section of hose.
Wait a moment for engine side to drain out (there is no way not to lose fuel).
Remove section of engine side hose, and slide on both new hose clamps (but left loose for now).
Remove the tank side hose (with bolt still screwed into it).
Quickly insert new hose on tank side line.
Position and tighten claims after any kinks in hose are removed.
Twisting hose will sometimes smooth out kinks - if present - and you are done.
BudW
shadango
Well-Known Member
The Volare will be in young guns, and my 72 sublime barracuda will be in ebodies....we do a LOT of walking (my feet and back hurt just thinking about what is to come..LOL) looking for parts etc......
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shadango
Well-Known Member
With God as my witness, the cap was off and the front end was pointed up hill.....LOL
No idea why it kept spewing.
Had the son use his thumb to plug the pipe coming from the tank while he dried and applied permatex with the other hand.....then handed him the new hose section with a clamp pinching the hose closed in the middle.....slid the hose on, did the hose clamp and then moved on to the front pipe. We lost the most fuel as he was trying to get the old hose off the pipe...LOL
