Vacuum Wipers

[Tumbleweed]

I have an F head with a double pump for fuel and vacuum wipers. The problem is I get no suction from the double pump for the wipers. On the intake manifold I have a place for a vacuum line. I currently have it plugged. �For proper hook up does the vacuum line go from the intake to the double carb/vacuum pump and then to the wipers? I dont know why the carb/vacuum pump would have 2 ports. There is only 1 line going to the wiper motor. Thanks - George

[calvinhunt]

This topic was discussed to quite some length in the old forum regarding the routing of vacuum lines from the intake manifold to the vacuum pump and from the vacuum pump to the wipers.  There were multiple responses with pics.  
I'm surprised that some of those same knowledgeable members haven't responded again here.  My Jeep is under wraps in cold storage till spring and without looking at it I can't direct you how to go.  Maybe someone with an inventory of photos or with a clearer understanding will still respond here with instructions.  As last resort go to the old forum at the following address: http://cj3apage.proboards.com   There you could search "fuel pump vacuum lines" and I believe you will find the help you are looking for.

[kristaga]

Maybe this will help:
http://cj3apage.proboards.com/index.cgi?board=Tech&action=display&thread=1109

[Tumbleweed]

Thanks a million. I am new to this forum so now I know where to look for some great images and support. Just finished a restoration on a 53 wagon. Noe starting a 51 CJ3A. Looks like I have a good source for help.
Kind regards, George

[Doug]

Just out of curiousity.  What is the purpose of connecting the vacuum line to the intake manifold.  I assumed that the vacuum was generated from the fuel pump and not the manifold.  Does the manifold provide back up vacuum in case the fuel pump vacuum fails or does the connection serve some other purpose.  Inquiring minds would like to know.  

[rocketeer]

The vacuum actually comes from the manifold. The purpose of the pump is to provide some backup vacuum when you are on the throttle, such as climbing a hill, in the rain, with the wipers going. Without the pump the wipers would stop but with the pump they'll keep going, although it may be a bit slower depending on the condition of the system, especially the wiper motors.

Larry

[Doug]

Thanks Larry, makes a ton of sense now that you describe it.

[rocketeer]

What we used to do, back in the day, was add a vacuum reservoir to the system. Just a metal airtight container of some sort with two tubes. You put it in-line between the pump and the wipers. The container gave you a reserve so that when you pressed down on the throttle the wipers did not slow down at all. Some model cars had them from the factory. Some cars experimented with air suspension and they had reservoir containers that you could use (Cadillac and Packard come to mind).

Larry

[jamesr]

My Dad built one out of an empty 1 qt. tomato juice can for our '49 Chevy.  Seems as I remeber it worked very well.  Jim