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'73 Cuda Fuel Tank Vapor Seperator Clogged?

Started by gzig5, June 13, 2018, 07:04:07 PM

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gzig5

Just put a new tank in that has the four vent tubes pointing to the front of the car. I'm reusing the vapor separator that those four vents are plumbed to.  I've cleaned/painted the outside and before I put it in I tried to blow air through to make sure it wasn't clogged up.  I am barely getting any air going through the single exit pipe, whether I blow in through it or through one of the four vent connections.  I plugged three of them and blew in the last and the air pressure ejected the plugs.  Am I hosed?  I found a post that suggest that there is some sort of valve in there and I assume it is a check valve that would prevent pressure coming in from the engine side?  If that is true and it is stuck, is there a method to free it up?  How does this silly thing work?  The thing it welded closed and I can't see anything looking in the pipes.  Not that I care to buy one, but I haven't seen where these are being reproduced.

jimynick

It's connected to the emissions canister on the frt inr apron and is really, just a way to vent the tank and have any vapour from it corralled into one line. Mine was rotted and a member here kindly geared me up with a used one. But failing finding one yourself, I'd stick a suitably sized drill bit through the nipples and drill them out thereby allowing the vapours to get out to the vent line. Just my  :alan2cents:
In the immortal words of Jimmy Scott- "pace yourself!"

gzig5

The four inlets are clear to the body of the unit but a small zip tie won't go in through the single outlet pipe.  It stops after the 90 degree bend but before the body.  I don't know if that is a blockage or some sort of valve.   I really don't want to cut that pipe off to fix it but maybe that's the only way.  Just trying to understand what if anything is in there before I attack it.  My charcoal canister is long gone.  I'll hook up the vapor separator assy and if I can't find a replacement charcoal canister from another model car, I'll do what others have and vent it through a fuel filter at the end under the hood.  One way or the other I need to vent the tank through that line so the fuel system can work properly.


Bullitt-

hopefully he will chime in, I seem to remember @Burdar got his working by soaking in something...  i think was a rust removal product.
.                                               [glow=black,42,300]Doin It Southern Syle[/glow]       

Burdar

I soaked mine in EvapoRust to clean out the inside.

Even after soaking mine, I couldn't blow through it.  I got a quick burst of air through it but then heard a "clink" sound and the air stopped. That's when I figured out there was a check ball in there.  If you suck and blow on the outlet(with three of the four tank lines plugged) you'll feel the ball moving inside.  I came to the conclusion that air is only supposed to pass through the separator when the check ball is in the middle of its travel.

In the real world, you'll never have a fast burst of air moving through it.  Just a slow transfer of fuel vapors through it.  My guess is the check ball is to stop raw fuel from entering the vapor line and making it's way up to the engine compartment. 

If you suck and blow on the outlet and the ball is moving freely, I think it's working properly.  :alan2cents:

gzig5

Thanks for the info.  Sounds like it is probably a loose ball that would prevent liquid flow from the tank side to the engine side.  I will see what I can accomplish before cutting into it. 
Would be nice if someone had a rotted one to cut open and educate the masses....

Burdar

Plug the nipples and fill it with EvapoRust.  That will clean out the inside.  Then suck/blow on the outlet and see if the ball moves freely.  If it does you should be good to go.  If the EvapoRust dries inside, it can get sticky.  Make sure to flush it out good after the soak.


gzig5

Good news.  I was using too much air pressure with the air gun.  This morning I shook it back and forth and could hear the ball rattling.  Blowing gently with my mouth, air goes through both ways.  Too much pressure pushes the ball against the stops at either end and blocks the flow.  Looks like it should be good to go.  Now to make the 25 bends to convert a roll of tubing into a fuel line.

Another question....where do you source the OEM style crimp on hose clamps at a reasonable cost?  I don't need OE parts but I like the crimp vs the worm gear clamps.  Single or double crimp are acceptable.

Burdar

Glad you got it figured out.

Any of the restoration supply companies will have those clamps.  If you have a local parts store that has oddball stuff, you might find them there and save shipping costs.  Other then that, try Roseville, R/T Specialties, Mega Parts exc...