1981 Ford F100 Revival (Parked for 12 years)

[rcarlisle]

It's a vacuum reservoir (and obviously a vacuum leak, now)

The bowl vent long your carburetor should be connected to a check valve and then to the charcoal canister.

I imagine that 40 years of engine heat and gas fumes has finally killed the rubber's elasticity.

Thanks Jim, I will look for a new coupler and line. The coupler must of shrunk if it is just a press fit.

How essential is the charcoal canister on these? When I had a BMW motorcycle, we usually eliminated them when they started failing.

I'm in NC and no inspections required of any sort, so if it were not there, no big deal. I'd leave it till it failed and caused issues. But is it necessary on these trucks?

 

[Jonathan]

Now question time. Why is there a can of beans in the engine compartment? And why does it leak when I crank the engine?

Oops - late to that part of the party. Never mind...

THat's a vacuum can. Not sure why it's leaking or why it has fluid in it. Possibly failing? Is that over near the heaterbox? I have one over there - it is a tank to keep vacuum ready for the vent controls from the dash. I think.

Might clean it out and check it, see if it holds vacuum.

No worries, I saved you a beer.

It probably won't hold a vacuum but I just ordered a new vacuum gauge. My old one got killed because I left it attached overnight to the old fuel tank. It kept pulling a vacuum and overflowed the reservoir and gummed up the internal workings with old fuel varnish. I will try to fix it but it won't hurt to have a backup anyway.

[Jonathan]

How essential is the charcoal canister on these? When I had a BMW motorcycle, we usually eliminated them when they started failing.

I'm in NC and no inspections required of any sort, so if it were not there, no big deal. I'd leave it till it failed and caused issues. But is it necessary on these trucks?

I followed the vent line from the fuel tank and it goes to that plastic canister. I guess the only reason I would leave it is I don't want to smell petrol fumes every time I walk by the truck. The fumes will go to that canister and then get eaten by the engine when it is running I think.

 

[rcarlisle]

How essential is the charcoal canister on these? When I had a BMW motorcycle, we usually eliminated them when they started failing.

I'm in NC and no inspections required of any sort, so if it were not there, no big deal. I'd leave it till it failed and caused issues. But is it necessary on these trucks?

I followed the vent line from the fuel tank and it goes to that plastic canister. I guess the only reason I would leave it is I don't want to smell petrol fumes every time I walk by the truck. The fumes will go to that canister and then get eaten by the engine when it is running I think.

Yeah it's no big deal. ON the BMW motorcycles, when it failed, it caused other issues that I can't remember right now. The only difference removing it made was fuel overflow at fillup if you overfilled.

I think mine is still down there on the truck - have no idea if it's hooked up or not. I haven't been getting any stray smells from the engine compartment.

One thing I figured out is that someone filled the washer bucket with antifreeze instead of washer fluid. Antifreeze will work as a windshield cleaner. HOWEVER, it does not evaporate quickly like washer fluid. I sucked it out and put proper washer fluid in.

I guess this could be a common mistake? Or at least semi common if you have no idea that single unit bucket is actually two separate compartments. Or someone else checking your fluids at a quickie change place? Something to be aware of.

[Jonathan]

Yeah it's no big deal. ON the BMW motorcycles, when it failed, it caused other issues that I can't remember right now. The only difference removing it made was fuel overflow at fillup if you overfilled.

I think mine is still down there on the truck - have no idea if it's hooked up or not. I haven't been getting any stray smells from the engine compartment.

One thing I figured out is that someone filled the washer bucket with antifreeze instead of washer fluid. Antifreeze will work as a windshield cleaner. HOWEVER, it does not evaporate quickly like washer fluid. I sucked it out and put proper washer fluid in.

I guess this could be a common mistake? Or at least semi common if you have no idea that single unit bucket is actually two separate compartments. Or someone else checking your fluids at a quickie change place? Something to be aware of.

My bucket is so dirty I didn't even see a separation between them. I thought at first it used the antifreeze to clean the windshield!

[FuzzFace2]

The bean can is actually a vacuum reservoir. It shouldn't leak and it shouldn't have anything in it. Some have fiberglassed their old one to repair it, but I'd recommend getting another one. There are at least two sizes of cans and then there's the plastic ball. Any of them would work.

As far as the hose, I think it is the vent hose to pull vapors from the bowl of the carb into the charcoal canister. And you should be able to replace it with a piece of fuel line the right size.

My ears were ringing about vacuum can & fiber glass

I was chasing a vacuum leak and came across the can was the cause. I found the can had a bunch of rust pin holes. Because of my work hours I never had time to hit junk yards but had the fiber glass rosin and the time to do a quick fix.

I pulled the can out of the truck, pulled the mounting bracket off the can this way I was left with just the can.Mixed up some rosin and coated the can, let it set up and gave it a 2nd coat.

When the rosin was dry I painted in black and put the mounting bracket back on and installed in truck.

The can is used to supply vacuum to the HVAC system when the motor is under a heavy load.\

There is a check valve in the supply to the can so the motor will not use the vacuum from the can.

My check valve did not work and the 2 new ones also did not work so when the motor is under a heavy load the HVAC door swings to defrost.

On the bowl vent fitting pull it out of the hose, stick it back in the carb and try to tap in it and see if itwill stay. If not I would clean the carb & fitting and use a little JB Weld and glue it back in.

That should hold it in place.

Dave ----

[FuzzFace2]

How essential is the charcoal canister on these? When I had a BMW motorcycle, we usually eliminated them when they started failing.

I'm in NC and no inspections required of any sort, so if it were not there, no big deal. I'd leave it till it failed and caused issues. But is it necessary on these trucks?

I followed the vent line from the fuel tank and it goes to that plastic canister. I guess the only reason I would leave it is I don't want to smell petrol fumes every time I walk by the truck. The fumes will go to that canister and then get eaten by the engine when it is running I think.

That is why mine is still hooked up.

Now for the vapor being eaten is the rest of the bowl vent line in place and if so is there a electric valve that tells when they get eaten?

I ask because so truck use the electric valve and others dont. If you have a "dont" you are in good shape.

Mine was missing some parts so I hooked it up to the top port on the PVC but this caused a vacuum leak because it was pulling to much vacuum.

My fix was to use the smallest Holley carb jet I had to restrict the vacuum but think it was still to big.

Because my MPG is poor I disconnected the vacuum and plugged as a test to see if it was pulling vapor from the tanks. I have not hooked it back up and it was not the reason for the poor MPG

Dave ----

[Jonathan]

The bean can is actually a vacuum reservoir. It shouldn't leak and it shouldn't have anything in it. Some have fiberglassed their old one to repair it, but I'd recommend getting another one. There are at least two sizes of cans and then there's the plastic ball. Any of them would work.

As far as the hose, I think it is the vent hose to pull vapors from the bowl of the carb into the charcoal canister. And you should be able to replace it with a piece of fuel line the right size.

My ears were ringing about vacuum can & fiber glass

I was chasing a vacuum leak and came across the can was the cause. I found the can had a bunch of rust pin holes. Because of my work hours I never had time to hit junk yards but had the fiber glass rosin and the time to do a quick fix.

I pulled the can out of the truck, pulled the mounting bracket off the can this way I was left with just the can.Mixed up some rosin and coated the can, let it set up and gave it a 2nd coat.

When the rosin was dry I painted in black and put the mounting bracket back on and installed in truck.

The can is used to supply vacuum to the HVAC system when the motor is under a heavy load.\

There is a check valve in the supply to the can so the motor will not use the vacuum from the can.

My check valve did not work and the 2 new ones also did not work so when the motor is under a heavy load the HVAC door swings to defrost.

On the bowl vent fitting pull it out of the hose, stick it back in the carb and try to tap in it and see if itwill stay. If not I would clean the carb & fitting and use a little JB Weld and glue it back in.

That should hold it in place.

Dave ----

Thanks for the tips Dave, do you have a link to your post if it has pictures? I will pull out the carb connection later and measure. I need some new line also.

[Jonathan]

How essential is the charcoal canister on these? When I had a BMW motorcycle, we usually eliminated them when they started failing.

I'm in NC and no inspections required of any sort, so if it were not there, no big deal. I'd leave it till it failed and caused issues. But is it necessary on these trucks?

I followed the vent line from the fuel tank and it goes to that plastic canister. I guess the only reason I would leave it is I don't want to smell petrol fumes every time I walk by the truck. The fumes will go to that canister and then get eaten by the engine when it is running I think.

That is why mine is still hooked up.

Now for the vapor being eaten is the rest of the bowl vent line in place and if so is there a electric valve that tells when they get eaten?

I ask because so truck use the electric valve and others dont. If you have a "dont" you are in good shape.

Mine was missing some parts so I hooked it up to the top port on the PVC but this caused a vacuum leak because it was pulling to much vacuum.

My fix was to use the smallest Holley carb jet I had to restrict the vacuum but think it was still to big.

Because my MPG is poor I disconnected the vacuum and plugged as a test to see if it was pulling vapor from the tanks. I have not hooked it back up and it was not the reason for the poor MPG

Dave ----

I was wondering what effect it would have on MPG. Fuel vapor I think should help correct? Because it can ignite.

 

[Jonathan]

How essential is the charcoal canister on these? When I had a BMW motorcycle, we usually eliminated them when they started failing.

I'm in NC and no inspections required of any sort, so if it were not there, no big deal. I'd leave it till it failed and caused issues. But is it necessary on these trucks?

I followed the vent line from the fuel tank and it goes to that plastic canister. I guess the only reason I would leave it is I don't want to smell petrol fumes every time I walk by the truck. The fumes will go to that canister and then get eaten by the engine when it is running I think.

That is why mine is still hooked up.

Now for the vapor being eaten is the rest of the bowl vent line in place and if so is there a electric valve that tells when they get eaten?

I ask because so truck use the electric valve and others dont. If you have a "dont" you are in good shape.

Mine was missing some parts so I hooked it up to the top port on the PVC but this caused a vacuum leak because it was pulling to much vacuum.

My fix was to use the smallest Holley carb jet I had to restrict the vacuum but think it was still to big.

Because my MPG is poor I disconnected the vacuum and plugged as a test to see if it was pulling vapor from the tanks. I have not hooked it back up and it was not the reason for the poor MPG

Dave ----

I was wondering what effect it would have on MPG. Fuel vapor I think should help correct? Because it can ignite.

Here is another mystery I found when I was under the truck. I noticed a cut off line. It almost looks like it could be fuel line. When I went to the the back of the truck to investigate the other side of the line was just tucked in. What was this line for and why is it cut off? The frame clip holding the line looks factory.