Windshield and vacuum tank questions on a late '22

[22touring]

Sure would like to have answers to these two questions concerning my late '22 touring car (similar to a '23). Thank you kindly in advance.

 

1. How do you rotate the upper and lower windshield sections into their horizontal positions?

 

and

 

2. What would cause gas to dribble out the bottom of my vacuum tank rather than flowing out freely?

[cahartley]

Sounds like it's time to take the vacuum tank apart.......yours should have 8 screws holding the top...pay attention to the orientation of the top to the tank.

Yours also should be a late tank in which the inner can has a very narrow flange and requires only one cork gasket.

Remove the top, lift out the canister and you're good to go to clean it out.

While you have it apart check the two tiny needle seats which are pressed into the top. If you should find one or both are loose a dab of Loktite will cure that issue.

The link is an excellent resource!

 

http://old-carburetors.com/1927-Dykes/1927-Dykes-072.htm

Edited August 14, 2015 by cahartley (see edit history)

[22touring]

Thanks for the reply, C.A. I like the way Dykes explained it.

 

My vacuum tank is supposedly rebuilt, and to my untrained eye it looks good. Before I pull it again (not that easy), I would be curious to see if anybody can suggest any diagnostic tests to determine, maybe using a vacuum gauge and pump, whether the problem is the vacuum valve, the atmospheric valve, the flapper valve or that it is plugged up.

 

I can feed gas to the engine from a separate source, so I can test the vacuum tank with the engine running.

 

Where's that Bob Scafani when you need him? I know he has worked on scads of these, and he must have a troubleshooting procedure.

 

And I still cannot for the life of me figure out how to rotate the windshield sections, although they are obviously intended to rotate for automatic air conditioning.

Edited August 15, 2015 by 22touring (see edit history)

[JayG]

The windshields are mounted by a pivot bolt to the the frame.  There are springs and ball bearings inside that allow the windshields to simply push out to certain stop spots.  Is yours rusted up so it won't work?  

[22touring]

My windshield pivots are clean and lubed, Jay, so do I just push on the windshield sections to rotate them?

Edited August 15, 2015 by 22touring (see edit history)

[JayG]

That's all it should take.  There is a little resistance and you'll see the springs compress inward at the frame pivot point as the windshield moves outward.

[cahartley]

Thanks for the reply, C.A. I like the way Dykes explained it.

 

My vacuum tank is supposedly rebuilt, and to my untrained eye it looks good. Before I pull it again (not that easy), I would be curious to see if anybody can suggest any diagnostic tests to determine, maybe using a vacuum gauge and pump, whether the problem is the vacuum valve, the atmospheric valve, the flapper valve or that it is plugged up.

 

 

You don't have to remove the unit......only the top.

The problem is unlikely any of those you mentioned.

Remove the little bent vent tube and see if the flow changes.

There are only two things to stop the free flow of gas: the vent and outlet.

Edited August 15, 2015 by cahartley (see edit history)

[22touring]

When I originally posted this, I had forgotten about this really great article on vacuum tanks which appears on allpar.com! It contains the troubleshooting procedure that I was looking for.

 

http://www.allpar.com/fix/fuel/vacuum-tank-fuel-pump.html

 

I really like that allpar.com site!

 

22touring

[22touring]

In order for a vacuum to develop in the inner chamber of the vacuum tank: (1) the vacuum valve must be open; (2) the atmospheric valve must be closed and must seal properly (both of these valves are in the top of the tank); (3) the flapper valve near the bottom of the inner chamber must be pulled closed by the vacuum in the inner chamber, and must seal properly; and (4) there must be a good air and fuel-tight seal separating the inner and outer chambers.

 

In addition, (5) the intake manifold tube must actually be delivering vacuum to the vacuum tank; and (6) the fuel line must be air tight all the way back to the gas tank.

 

And perhaps most importantly: (7) There cannot be any mud dauber nests or spider webs blocking any of the fuel or vacuum lines. When you get those, you need to push successively larger gauges of wire through the line until you have pushed the largest possible size wire through, because that is the only way to be sure that you have removed everything.