fuel vent hose question

[johnnybgood74]

hey fellas, my question is this; i have the tanks that had the venting system that had the canister and the little bottle that has the four plastic lines going into it. i have deleted all of that stuff and was wondering if i can cap the little nipples coming off the tanks? is the vent tube that hooks into the filler neck enough venting or do i need to do something to make it vent through the nipples?'

Thanks!

 

[broncnaz]

You can block off all the nipples. The only vent you need to worry about is the gas cap you'll need a vented type if it doesnt already have one. The vent ube for the filler hose is just for filling up so you get less gas kick back it doesnt do any other venting.

 

[70_Steve]

The only vent you need to worry about is the gas cap you'll need a vented type if it doesnt already have one.

The Stant part number for the vented gas cap is 10623, for 66-70 Broncos. 71 and up is the non-vented cap.

Also, understand that the "vented" cap actually has a check valve in it. It will allow air into the tank, to prevent the tank from being at less than atmospheric pressure (vacuum). But it will not allow pressure (gas fumes) to escape. Be careful when removing the gas cap!!

I read somewhere that the filler neck is different for the vented and non-vented caps, but I have no way to prove or disprove... Anyone know for sure?

 

[chuck]

Hook that stuff back up. It works and cost you nothing. Without it you will have either vacuum or pressure in your tank and you don't want either plus if you roll the tank will leak and if you park in a enclosed garage you will have a gas smell.

 

[zeeman1]

Vented cap will do the trick. That's how mine are both setup, I park in the garage every night and never had an issue with gas smell out of any of the 3 tanks.

 

[broncnaz]

X2 while I rarely park in a garage if the vented caps are working correctly they dont let fuel vapor out.

 

[chuck]

X2 while I rarely park in a garage if the vented caps are working correctly they dont let fuel vapor out.

Your right about how the cap works. The problem is when the gas expands the vaper should go to the expansion tank then to the charroal canistor, then to the air cleaner. All that equals no pressure and no gas smell. If you plug up the vents the pressure will/can build to the point that it will over power the carb float and cause raw gas to go into your engine. The early years did not have this system and have the above problems. You may not notice them but the problems are still there. If you have the vent system plugged smell your oil after a hot day of setting in the garage. I have told you how things work so if you leave the vaper system off please consider selling that old junk to me.
OK OK, you could also look at the vaper recovery drawings or search the old post here about gas smell.

 

[bptommy]

everyone seems to have a different op on this, but i have to agree with chuck. I went the vented gas cap route and had alot of problems with gas smell in my garage and house. As soon as I hooked my vapor recovery back up all the smell went away. Looking where everyone was posting from maybe the climate has something to do with the different results. Chuck and I are both in texas. Looks like we had az and wa states here so maybe that is the thing that creates a different result. ...good luck;D

 

[RVH]

Keep it in place

Concur with, Chuck. It cost nothing to keep it in place! BTW - I will take second dibs after Chuck if you want to sell your evap bottle.

Rob

 

[chuck]

I can see that. If the temp doesn't change much the expansion wouldn't be much. Years ago I had a customer that worked out in Boron CA that brought his Toyota in because it would lock up/ not start when he went to leave work. He had a friend pull him around the lot with a dozer but only slid the rear wheels. Very long story short the vapor recovery system was plugged and the heat of the day would force the gas from the tank into the cylinder and cause hydro lock.