What Is This Part?

[Mark A.]

I have a 71 LT-1. Underneath the vacuum tank in the engine compartment, is another round tank. It says Rochester Products on a cap on top of the tank. 1 hose is connected to the PCV system, and the other goes to the rear of the car. I have not found any reference, pictures, or drawings of this can in any of the shop manuals I have. I'm assuming it has to do with the pollution system? Does anyone know what this tank is called, and what it's function is? Thanks, Mark

[Patrick H.]

Re: What Is This Part?

Mark,

It's a charcoal-filled canister used for emissions purposes.

The line going to the back of the car attaches to the upper left portion of the fuel tank. The lines on top of the canister attach to the PCV system. When the car is running it "creates" vacuum which then draws any gas fumes from the fuel tank thru th e charcoal canister and into the engine to be burned. I believe that the charcoal is used as a "fume depository" for any fuel vapors that are emitted between times that you use the car. when you use the car, those fuel vapors are slowly purged off and burned.

At least I think that's how it works.

Patrick

[Paul O.]

Re: What Is This Part?

Mark that is your charcoal canister for the emission system. The line going to the rear goes to the gas tank and is the tank vent. On the side of your tank drivers there is a small check valve looks some what like a small house with 2 hoses connected to it. When your car is sitting not running the vapors from the tank go up the line to the canister and are held there till you start you engine and the are vacuumed to the carburetor and the vapor are burned. There is a cover with a small hose on the bottom the the canister if still there and a yellow filter that is where the air is sucked up and through the charcoal going to the carburetor. Paul 18046

[Mark A.]

Re: What Is This Part?

Thanks guys for the explanation! Mark

[Terry M.]

Re: What Is This Part?

Mark,
There should be an explaination in the FSM (Factory Service Manual). You do have one of those, right? There is a whole chapter on emissions. Look it up.

[Alan S.]

Re: What Is This Part?

Hi Mark,
Here's a picture or two of the separator that the hard line on the driver's side rail connects to back at the gas tank.
Regards,
Alan