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Roller valve - Part Question

Roller valve - Part Question

JeepDave

Jeeper
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Location
Frederick, MD
Vehicle(s)
'78 CJ7, 304
My rollover valve was spewing gas so I decided to take it apart and have a look-see. Cleaned it, put it back together and reconnected all the hoses. Ran my rig for about 20 minutes only to realize gas was streaming out of the canister portion. Took it apart again and upon closer inspection, when the float goes up, it doesn't come back down in the cylinder, it goes up too high coming out of the cylinder getting cocked at an angle allowing fuel to pour in and continue forward toward the canister (if I had one).

vent_01.webp

vent_02.webp

After realizing it was a loss cause I decided to pull it out and simply clamp off the two hoses coming out of the gas tank, no more gas leak. However, I'm worried because the tank can't breath. Below are three hoses, two coming out of the gas tank and one that runs to the front of the Jeep (I put a screw in it for the hell of it, no canister in the engine compartment).

gas_tank_tubes.webp

I'm looking for a part I can push into one of the hoses coming off the gas tank so as to allow the take to vent w/o introducing contaminants.

s-l400.webp

Would the piece above fit the bill? I was going to back out one of the screws from one of the hoses coming off the gas tank and plug it with the piece sticking out. Is it safe to assume that I can simply zip tie this somewhere up high to avoid contact with water? Thanks all!! JD
 
My rollover valve was spewing gas so I decided to take it apart and have a look-see. Cleaned it, put it back together and reconnected all the hoses. Ran my rig for about 20 minutes only to realize gas was streaming out of the canister portion. Took it apart again and upon closer inspection, when the float goes up, it doesn't come back down in the cylinder, it goes up too high coming out of the cylinder getting cocked at an angle allowing fuel to pour in and continue forward toward the canister (if I had one).

vent_01.webp

vent_02.webp

After realizing it was a loss cause I decided to pull it out and simply clamp off the two hoses coming out of the gas tank, no more gas leak. However, I'm worried because the tank can't breath. Below are three hoses, two coming out of the gas tank and one that runs to the front of the Jeep (I put a screw in it for the hell of it, no canister in the engine compartment).

gas_tank_tubes.webp

I'm looking for a part I can push into one of the hoses coming off the gas tank so as to allow the take to vent w/o introducing contaminants.

s-l400.webp

Would the piece above fit the bill? I was going to back out one of the screws from one of the hoses coming off the gas tank and plug it with the piece sticking out. Is it safe to assume that I can simply zip tie this somewhere up high to avoid contact with water? Thanks all!! JD

Not sure...but you should have some sort of venting system by the fuel inlet / filler. I think you could just run a fuel line from one of those little outlets right to the other in a horseshoe, clamp them both and be fine if the standard vent setup is functioning.
 
If you do not have a gas tank vent, a vacuum will form in the gas tank as the tank drains of fuel. This will eventually prevent fuel from getting to the pump. A vented gas cap will help here if it operates correctly.
 
I’m still at a loss at to why you have fuel traveling vertically up into your rollover valve in the first place, I wonder if you put a light weight spring on top of your float if that would help stop it from sticking, like a spring from a Holley carb vacuum advance


Sent from Texas using Tapatalk
 
The fuel pickups for the check valve and rollover valves are located on the left and right side in the inside top of the gas tank. So to get fuel in them would require gas sloshing around in a fuel tank with lots of fuel in it or a lot of off camber driving like off road. Still the valve should not stick open. So if you still have a sticking problem with it after inspection and cleaning, replacement would be a good choice. From what I understand they only came in the CJ.
 
Not sure...but you should have some sort of venting system by the fuel inlet / filler. I think you could just run a fuel line from one of those little outlets right to the other in a horseshoe, clamp them both and be fine if the standard vent setup is functioning.

Thanks, doesn't using a single tube from one outlet to the other create the same issue? It seems like creating a horse shoe creates a closed system not allowing air to escape. Do you have a picture of what you're referring to?
 
I’m still at a loss at to why you have fuel traveling vertically up into your rollover valve in the first place, I wonder if you put a light weight spring on top of your float if that would help stop it from sticking, like a spring from a Holley carb vacuum advance


Sent from Texas using Tapatalk

Thanks for the idea. I still have the part and plenty of hose. I'll take a look and see if that would work.
 
The fuel pickups for the check valve and rollover valves are located on the left and right side in the inside top of the gas tank. So to get fuel in them would require gas sloshing around in a fuel tank with lots of fuel in it or a lot of off camber driving like off road. Still the valve should not stick open. So if you still have a sticking problem with it after inspection and cleaning, replacement would be a good choice. From what I understand they only came in the CJ.

Yeah I too couldn't figure out why so much gas was being forced so far (and vertically) under so much pressure. I'm definitely not off roading yet so continually flooding the vent ports isn't an issue. I'm sitting on a stock suspension with 33s so I'm definitely not flying around curves :) I have to replace the fuel sending unit, maybe that's contributing...

I don't have to worry about emissions in MD and the PO took out the canister so I figured that I'd do away with the who thing completely. Just need to find a part that'll vent the gas tank. A vented gas cap is a good idea although I like the original-looking gas cap (slim, silver with black grip).
 
Thanks, doesn't using a single tube from one outlet to the other create the same issue? It seems like creating a horse shoe creates a closed system not allowing air to escape. Do you have a picture of what you're referring to?



Well you’re not allowing fuel to escape. You’re venting isn’t done there it’s done on the other side as a part of the filler structure / gas cap.


Sent from my iPhone using Tapatalk
 
I'm looking for a part I can push into one of the hoses coming off the gas tank so as to allow the take to vent w/o introducing contaminants.

s-l400.webp

Would the piece above fit the bill? I was going to back out one of the screws from one of the hoses coming off the gas tank and plug it with the piece sticking out. Is it safe to assume that I can simply zip tie this somewhere up high to avoid contact with water? Thanks all!! JD

When I converted our Jeep to an in tank pump, this is pretty much exactly the breather valve that I installed. Works great. I don't see why it wouldn't work for your application. I think you could plumb it into one of the old hoses, just make sure that it is mounted in the upright position. These valves won't work if they are mounted sideways.
 

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