Fuel separator question (1 Viewer)

[OKMike]

77 FJ 40 Fuel tank question. It is de-smogged but still has the charcoal canister. PO had the three outlets on the fuel tank that go to what the diagrams call the "fuel separator" essentially blocked off--just pieces of hose on them with bolts stuffed into the ends of the hoses. No fuel seperator in sight. There are plenty of used seperators on the interwebs and the CCOT diagram that shows where the lines go. Seems like an easy fix. I presume this is a part I need so the charcoal canister will do its job? If so, where is it mounted? Thanks!

 

[John Smith]

 

[Pierps]

To tack on- it mounts to inside the silver piece in John's picture. If you trace the line connected to the canister back along the passenger side of your truck, it should come up through the floor underneath this silver cover. That line connects to the bottom of the separator. So yes, you need those three hoses connected to the separator in order for the canister to do its job.

The vent hoses are there to allow the gas tank to vent. On hot days, the gas vaporizes and will create pressure in your tank if it can't vent. It's possible the PO installed a vented gas cap to address this. So if you hook up your separator correctly, you should no longer need the vented gas cap, and will probably smell less fumes in the vicinity of your truck.

Also, let me add one important thing- you need to make sure to put in a rollover valve between the separator and the canister. If you don't, in the unfortunate event of your truck ending up on its lid, gas will flow up through your vent lines and potentially leak. Not something you want in a serious accident.

 

[OKMike]

To tack on- it mounts to inside the silver piece in John's picture. If you trace the line connected to the canister back along the passenger side of your truck, it should come up through the floor underneath this silver cover. That line connects to the bottom of the separator. So yes, you need those three hoses connected to the separator in order for the canister to do its job.

The vent hoses are there to allow the gas tank to vent. On hot days, the gas vaporizes and will create pressure in your tank if it can't vent. It's possible the PO installed a vented gas cap to address this. So if you hook up your separator correctly, you should no longer need the vented gas cap, and will probably smell less fumes in the vicinity of your truck.

Also, let me add one important thing- you need to make sure to put in a rollover valve between the separator and the canister. If you don't, in the unfortunate event of your truck ending up on its lid, gas will flow up through your vent lines and potentially leak. Not something you want in a serious accident.

Thanks so much, Brother! this was incredibly helpful.

 

[Pierps]

For the rollover valve, it can be as simple as something as this:

Fuel Vent Check Valve, In-Line for 3/8 inch I.D. Hose | Pegasus Auto Racing Supplies

A one-way valve in the fuel cell vent line can prevent spilled fuel if the car rolls over. Our compact check valve fits into the end of your 8AN vent hose.

www.pegasusautoracing.com

It works using gravity, so you need to install it plumb/vertical in order to work correctly.

 

[Sthd]

Here is a pic of a fuel sperator, it has a 2 way valve on output end. It remains closed until vapor pressure builds up to 0.48 in. Hg and goes into charcoal canister. If there is build up of pressure to canister side of 0.60 in. Hg it sends it back to fuel tank. Pics will not load up for some resason.