Where to run gas tank vent line with tank moved to rear of truck?

[69gmcshorty]

wow seems like an epidemic. I have a 49-52 passenger car tank in my 69' and I am just now getting it all hooked up. I am questioning my filling and driving problems that may be what others here are having. I have the filler line and a vent line, (vent that is coming out of the tank to its own line not hooked up to the filler line.
Question: will my one vent line be ok to fill and run properly with no vapor lock? meaning will it be able to fill and drive ok sucking air in from the one vent line?

[WinDancer]

Last update:
After being able to fill on slow speed I sorta forgot about it.
After several months I reinstalled the fill-through gas cap, which helped hold the fill neck in position. That allowed to fill at full speed.
After more than a year everything is still working correctly.
My opinion, now:
You need the vent on the fill tube, and also a second vent. I am a smoker and am not interested in a fire, so I ran the second vent tube to the engine compartment and plumbed it straight into the air cleaner.
I LOVE the fill-through cap. Mark found that for me when he swapped beds, installed the hotter cam and rewired the entire truck. I tried to find another cap and was told by all the parts houses that they were no longer making/selling them.
Mark does real nice work!
Take care,
Dave

[68anniversary]

Just curious about you running the vent to your air cleaner? What would happen if you had a backfire at the carb?

[swamp rat]

Originally Posted by 68anniversary

Just curious about you running the vent to your air cleaner? What would happen if you had a backfire at the carb?

Inquiring minds wanna know.....

[PanelDeland]

I think I would run the second vent up in the fender and use a fuel filter on the end.Should vent either way and keep crap out of the tank.DMSSC or KISS

[WinDancer]

Don't think it would be dangerous- be tough for fire to follow that line clear back to the tank. Think the danger from a cigarette igniting fumes under the fender or under the bed would be MUCH higher. Happy camper the way it works now.

[Grumpy65]

Bought a 65 C10 with a rear mount tank and top mount filler. Went to fill her up and as it reached full, fuel began running down the sides of the tank. First thought was full filler clamps not tight enough but noticed that there is a vent line on this side of tank. Haven’t gotten a change to take tank down to check it out but my question is where is thes vent line suppose to run. It’s an LMC tank.

[Beuford]

I used an S10 Filler. and the vent is in the fill tube and worked great for me.

[cj847]

I went thru this on a truck I recently bought. They had just finished the rear tank install. Anyway, any time I loosened the cap there was either huge suction or huge pressure (depending on temp). So, I knew they left out the vent. I bought a remote vent and mounted it per these instructions. Works perfect.

https://www.tanksinc.com/index.cfm?p...id=-1&mode=cat

This is the vent/rollover valve I used:

https://www.tanksinc.com/index.cfm/p...prod/prd98.htm

EDIT: I just realized you asked where. I put mine in the rear corner stake pocket.

[Accelo]

I ran a hose up through the hole in the bottom of a stake pocket. Then attached the vent to the end of the hose and let it drop to the bottom of the pocket. Attached the end of the hose to the tank vent.
Keeps it out of the crap underneath the truck. The vent I used will not let water in.
The tank came with the roll over valve and the hose is attached to it.

Vents are somewhat like grounds. You can't have enough of them.
I like it when an old thread becomes relevant again.
Cheers.

[MySons68C20]

Originally Posted by Accelo

I ran a hose up through the hole in the bottom of a stake pocket. Then attached the vent to the end of the hose and let it drop to the bottom of the pocket. Attached the end of the hose to the tank vent.
Keeps it out of the crap underneath the truck. The vent I used will not let water in.
The tank came with the roll over valve and the hose is attached to it.

Vents are somewhat like grounds. You can't have enough of them.
I like it when an old thread becomes relevant again.
Cheers.

Exactly how I did it no issues.

[Already Gone]

I used a gas fill tube from a square body Suburban. It had the vent tube on it so used a piece of it and then ran to the gas tank.

[1971Stepside]

I'm running a Boyd tank. Here is how I ran mine.

[Larry S]

When I originally did my blazer tank install, I used a filler off a 2500 express van. I did some cutting and refabricating on it. I hinged the bedside reflector. I had only 1 vent in the filler. When I finally got truck on the road, it had huge amount of pressure when you would drive truck and unscrew gas cap and it wouldnt take gas at the station. So I added 1 vent hose routed/ attached behind a bed sill up into bedside. That helped with the pressure but it still wouldn't take gas. Then I added another on the other side. That eliminated all pressure unscrewing the cap and made it take gas better but not 100%. Last thing , I tried was taking the vent completely out of filler and teed it into my other vent hose on the drivers side. That made everything right on my application. It takes gas now and no pressure.
If I had the whole thing to do again, Id went with the boyds tank. I had a never used blazer tank on hand, but I had to do alot of modifications to make it work. I put the tanks inc pa4 pump in it.
Posted via Mobile Device

[Larry S]

Originally Posted by Larry S

When I originally did my blazer tank install, I used a filler off a 2500 express van. I did some cutting and refabricating on it. I hinged the bedside reflector. I had only 1 vent in the filler. When I finally got truck on the road, it had huge amount of pressure when you would drive truck and unscrew gas cap and it wouldnt take gas at the station. So I added 1 vent hose routed/ attached behind a bed sill up into bedside. That helped with the pressure but it still wouldn't take gas. Then I added another on the other side. That eliminated all pressure unscrewing the cap and made it take gas better but not 100%. Last thing , I tried was taking the vent completely out of filler and teed it into my other vent hose on the drivers side. That made everything right on my application. It takes gas now and no pressure.
If I had the whole thing to do again, Id went with the boyds tank. I had a never used blazer tank on hand, but I had to do alot of modifications to make it work. I put the tanks inc pa4 pump in it.
Posted via Mobile Device

Posted via Mobile Device

[Larry S]

When I originally did my blazer tank install, I used a filler off a 2500 express van. I did some cutting and refabricating on it. I hinged the bedside reflector. I had only 1 vent in the filler. When I finally got truck on the road, it had huge amount of pressure when you would drive truck and unscrew gas cap and it wouldnt take gas at the station. So I added 1 vent hose routed/ attached behind a bed sill up into bedside. That helped with the pressure but it still wouldn't take gas. Then I added another on the other side. That eliminated all pressure unscrewing the cap and made it take gas better but not 100%. Last thing , I tried was taking the vent completely out of filler and teed it into my other vent hose on the drivers side. That made everything right on my application. It takes gas now and no pressure.
If I had the whole thing to do again, Id went with the boyds tank. I had a never used blazer tank on hand, but I had to do alot of modifications to make it work. I put the tanks inc pa4 pump in it.
Posted via Mobile Device

[old51sedan]

Originally Posted by Livrat

As requested, here is a couple...

I have pretty much the same installation in my truck, works great.