Vacuum tank question

[vergil]

I've been trying unsuccessfully to get the vacuum tank on my '16 functioning properly. Hooked it up the other day and it filled right away. As near as I can fugure the valve lever gets hung up and it stops pumping. Is there anything I can do short of replacing the entire unit? I did replace the springs and everything else is in good condition.

[Guest cben09]

Lift the unit out,,,

Lift the float up and down,,,see that it moves evenly,,

Could one spring be stronger,,tipping the lever sideways,,

These units are simple and really relatively trouble free,,

They really work,,

There is a thread from a few months ago if you can find it,,,long thread I think,,

Cheers,,Ben

[Guest 1930]

Have you had the tank out and apart yourself Vergil, if not I can post a picture of one in pieces if that would help, like Ben said simple units.

If you were confident enough to take it apart I bet you could see what might be going on

[Guest cben09]

Taking it apart is essential,,,

The gasket should be in there,,BUT its NOT fussy,,

Dont overtighten the screws,,,

ITS a casual piece of lo tec equipment,,

See that there is no GOO on the flapper valve,,also that its not broken,,

by broken I mean ,in 2 pieces,,

Good luck,,,Ben

[Guest cben09]

On installing the float,,,let it hang down

Put 2 fingers on top of float,,to steer it around,,,control,,

Now you can feel the thing the pin goes in,,4 pie holes and the CENTER hole

Now thats easy,,,,,,,try let it hang loose,,and it will take 2 forevers,,

Cheers,,Ben

[DavidMc]

<!--[if gte mso 9]><xml> <w:WordDocument> <w:View>Normal</w:View> <w:Zoom>0</w:Zoom> <w:PunctuationKerning/> <w:ValidateAgainstSchemas/> <w:SaveIfXMLInvalid>false</w:SaveIfXMLInvalid> <w:IgnoreMixedContent>false</w:IgnoreMixedContent> <w:AlwaysShowPlaceholderText>false</w:AlwaysShowPlaceholderText> <w:Compatibility> <w:BreakWrappedTables/> <w:SnapToGridInCell/> <w:WrapTextWithPunct/> <w:UseAsianBreakRules/> <w:DontGrowAutofit/> </w:Compatibility> <w:BrowserLevel>MicrosoftInternetExplorer4</w:BrowserLevel> </w:WordDocument> </xml><![endif]--><!--[if gte mso 9]><xml> <w:LatentStyles DefLockedState="false" LatentStyleCount="156"> </w:LatentStyles> </xml><![endif]-->Did you replace the tension springs on the lever arm with the correct ones? The lever arm needs to snap over centre up and down, if its not snapping down maybe the springs are incorrect. Also there is a half round flat spring between the lever and the float, if that is missing or broken the vacuum tank will not work. There have been a number of previous threads on this site that are worth reading plus webs sites such as this one which also shows the flat spring I am referring to:

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If I may be a pedantic, these are not strictly "pumps". They are vacuum tanks that simply use engine vacuum to reduce the pressure in the vacuum tank to less than the pressure in the fuel tank which draws the fuel up into the vacuum tank where it flows under gravity to the carburettor.

[DavidMc]

Ben is right on, that is a very likely cause of your problem, it can takes a few attempts to get the pin on the underside of the float to enter the centre hole in the bottom of the tank. If it is not entered the float will hang up.

[Guest cben09]

AAAAAhhh,,ok now look for bent needle,,,,Ben

[Guest cben09]

Just a thought,,,,

Has anyone ever seen a worn out Vacuum tank???,,,,

Cheeers,,Ben

[Guest 1930]

Just a thought,,,,

Has anyone ever seen a worn out Vacuum tank???,,,,

Cheeers,,Ben

Yeah all the time, that pesky water and the bottom of a tank dont mix very well

Wore right on thru

[Guest DodgeKCL]

I suppose this is redundant ,but, vacuum tanks work on exactly the same principle as the float in the carb. Except instead of the gasoline arriving from a pressure device as in a more modern carb system,vacuum is used to suck gasoline from the rear of the car into the vacuum tank where it drops by gravity to the carb. The float uncovers the vacuum port when it drops below a preterdemined level to refill the tank. Same as a carb float releasing the needle valve to allow more gas to be pushed in. Actually both carb floats and tank floats work to maintain a set level determined by some part of their linkage. Like a carb float, a vacuum tank float must not touch the sides of the tank and must float free. They also must be air tight ( liquid tight? ) or they will drown and sink to the bottom of their respective float chambers. You can hear the gasoline in them by shaking them. It is possible that some gasoline in a float could make the float tilt to one side and cause a sticking problem? You can test it with water. Take the tank off the car and remove the lid and pour water slowly into the tank. The float should rise and do so straight up without rubbing on anything. Open the petcock on the bottom, and the float should slowly drop again without hanging up. With water outside the vehicle you can do this ad infinitum without having to use the engine vacuum and play with gasoline. You would want to dry out the tank thoroughly before reinstalling it.

Edited June 12, 2012 by DodgeKCL (see edit history)

[Guest cben09]

Take the pipe plug out of lid,,,,

Take 12" piece of coathanger wire and poke straight down,,,carefully,,

Feel top of float,,,push fently,,If no movement upper tank emty,,or float is sunk

If it goes down ,,say 1" its got gas,,,

In the down position,,there should be suction in the chamber,,

If not ,,disassemple and look for air leak or pluged line to tank,,

Cycle time w/ emty lower chamber,,2-5 sec

cycle time w/ full lower chamber,,a minute or two,,or more,,

as engine uses at idle,,,,

Hope this helps,,,Ben

[vergil]

Thank you all for your sage advice. I took the tank apart and checked it out thoroughly. Sure enough it would "hang up". Upon closer examination I noticed that one of the springs was improperly installed, perhaps by half a turn. I reinstalled the spring and got a perfect up and down motion. I will reinstall the tank this weekend. Amazing that such a slight difference would cause the imbalance. It should work, but if it doesn't, I'll just go back to the electric pump.

Bill

[Guest cben09]

Over the years I have had much less problems with the vacuum tank

AND its easier to deal with on the road,,

THE only issue I see here is that this info is no longer at the local hardware store,,

forgottn technology,,

Now that you know whats inside,,,how simple can it be,,,

Cheers,,Ben