Vacuum line and Fuel pump

[Rigormortor]

Hello all. I was looking at my carb adjusting it and I notice a vacuum line coming off the top front of the intake manifold bends down and stop above the fuel filter. Someone put a rubber cap on the vacuum line. On top of the fuel pump are 2 1/4 nipples with nothing attached to them. with the engine running one nipple feels like it is pushing out a little bit of air while the other one pulls a small amount of vacuum. Should the vacuum line be hooked to the fuel pump? What do you guys think?

[Guest]

Hey Greg,
On my '60 Thunderbird (Christine) one goes to brake power booster, the other goes to the vacuum wipers.
Richard D. Hord

[Rigormortor]

Hey Greg,
On my '60 Thunderbird (Christine) one goes to brake power booster, the other goes to the vacuum wipers.
Richard D. Hord

Also forgot to mention the vacuum line is a 2 piece and one line runs along the valve cover and connects to the brake booster, the other line runs down to the fuel pump but stops and is plugged off

[Guest]

Hey Greg,
The other one should go up and attach to a steel line that runs in front of the carburetor over to the passenger side of the engine, across the top of the valve cover and connect to a rubber hose that connects to the vacuum wipers above the heat/air fan motor!
Richard D. Hord

[Rigormortor]

Hey Greg,
The other one should go up and attach to a steel line that runs in front of the carburetor over to the passenger side of the engine, across the top of the valve cover and connect to a rubber hose that connects to the vacuum wipers above the heat/air fan motor!
Richard D. Hord

I did some reading and found the one line should connect to the fuel pump and the other line goes to vacuum wipers. My wipers were converted to electric so I guess the one line was removed and the vacuum disconnected from the fuel pump as it didnt need it. Maybe the vacuum was just directed through the fuel pump? I never heard of vacuum in a fuel pump for any reason.

[KULTULZ]

I did some reading and found the one line should connect to the fuel pump and the other line goes to vacuum wipers. My wipers were converted to electric so I guess the one line was removed and the vacuum disconnected from the fuel pump as it didnt need it. Maybe the vacuum was just directed through the fuel pump? I never heard of vacuum in a fuel pump for any reason.

What you have is called a TWO-STAGE (or COMPOUND) FUEL PUMP, i.e. the lower section is the fuel pump and the upper section is a vacuum pump. The vacuum pump purpose is to supply a vacuum source for vacuum accessories when manifold (engine) vacuum falls under a certain degree (partial or WOT operation) and is unable to operate the vacuum accessories. It works in conjunction with actual engine (manifold).

[Rigormortor]

What you have is called a TWO-STAGE (or COMPOUND) FUEL PUMP, i.e. the lower section is the fuel pump and the upper section is a vacuum pump. The vacuum pump purpose is to supply a vacuum source for vacuum accessories when manifold (engine) vacuum falls under a certain degree (partial or WOT operation) and is unable to operate the vacuum accessories. It works in conjunction with actual engine (manifold).

Ok, so it is ok to disconnect the vacuum hoses from the fuel pump and cap the vacuum line going to the manifold.

[Guest]

Hey Greg,
By going back and looking at some pictures you posted, you have a brake booster under the dash. No you cannot cap off the vacuum line to the brake booster! You will lose all power assist to you brakes!!! But you do need to put a cap over vacuum line on fuel pump that is not being used!
Richard D. Hord

[Rigormortor]

Hey Greg,
By going back and looking at some pictures you posted, you have a brake booster under the dash. No you cannot cap off the vacuum line to the brake booster! You will lose all power assist to you brakes!!! But you do need to put a cap over vacuum line on fuel pump that is not being used!
Richard D. Hord

Yeah I saw the little booster, im not going to touch anything.... just leave it all alone.