Manual Selector Valve????

[Breadfather]

Ok, So I have been searching this forum and the internet and I cant seem to find a post that discusses my issue.  I have a 77 K10 Bonanza with a 400ci TH350.  The guy I bought it from bypassed the drivers side tank at some point and has only been using the passenger side.  I would like to have both tanks working again.  So I removed the drivers side tank to get a look at the sending unit to make sure I ordered the right one.  I have been trying to locate a diagram showing me how to re hook everything back up and have the fuel gauge work properly.  All I can find are diagrams showing selector valves that have a plug or an electrical connector of some kind attached to it.  My selector valve is on the floor under the seat and it has three ports coming off of the back of it.  No plugs. No connectors. Just 3 brass barbs.  There is no switch on the dash and I cant seem to find a place where one was at some point.  So my questions are, did these trucks ever come from the factory with only a manual valve?  If so how do I hook everything back up so the gauge works properly?  Did this guy replace the original electrical valve with a manual one?(which doesn't make sense if he was going to bypass it)  If this is the original set up how do I make sure the gauge works correctly as I cant seem to find a wire that is supposed to hook up to the drivers side sending unit?  The drivers side sending unit only has 2 tubes coming out of it and a threaded connecter on the top that was not hooked up to anything.

Can anyone shed some light on this?

[bake315]

Do the manual valves look something like this?

[zieg85]

I had 1 switch like that on my 72 that had the stock 20 gallon behind the seat and 2 saddle tanks under

[Breadfather]

That is exactly what it looks like, but there is only one valve.

[bake315]

I had 1 switch like that on my 72 that had the stock 20 gallon behind the seat and 2 saddle tanks under

Yep, our '72 Longhorn had that as well.

[bake315]

That is exactly what it looks like, but there is only one valve.

Interesting that there is only the one, and that it's on a '77.  In my case one was for the supply line and the other for the vent line.  This was on my '73.  In 1974, they started doing the switch (some push/pull, some rocker) on the dash by the ashtray.  On my '73, there was also a switch, but all it did was allow you to flip back and forth between sending units - the actual tank switching was done manually via the valves.

Attached is how my valves looked from the underside, as well as a picture of the sending unit switch.

[VileZambonie]

We really need to make this and the other thread we started on this into a tech article. I did a lot of research on this and the early 73-75 push/pull in dash knob actually controlled a cable which manually operated the selector valve between tanks. I've been trying to keep my eyes open for a factory setup to get more details/pics. Sounds like what you have is an add on dual tank setup. If your truck came factory with dual tanks it would say it on the SPID label and would have it in the dash. Over the years lots of people setup dual tanks in many configurations or "redesigned" the factory system. When I bought my 74 someone had eliminated the push/pull setup and installed a toggle switch to a pump so the left tank would feed the right tank and the right tank was always the source tank 

[bake74]

     This is very interesting and should be made into a tech article, and I can totally see how over the years everyone was adding tanks and trying to make a better system.  Now there could be all kinds of variations.

[VileZambonie]

I've been compiling data. As soon as someone can get some pics of the push pull operated valve I will write up a complete article.

[Breadfather]

Well sorry I have been out of town for a few days and have not been able to get on here.  So I looked at the label in the Glove Box and I could not find anything on there that says dual tanks.  However; the gas cap spot on the side of the bed on both sides look factory.  So I guess someone could have put a new bed on there that was from a truck of the same color? What side tank would have come stock if the truck did come with only one tank?  How do I hook up the drivers side tank, so it all works correctly and the gauge reads properly?  Do I have to get a new valve and a switch? 

It almost seems to me that the supply line on the drivers side went to the valve that went over to the passenger side somewhere.  Im not sure if it went to the sending unit on top of the tank or it teed into the line somewhere.  It then seems as if another hose went back over to the drivers side tank from the passenger sending unit.  Does that make any sense?  I just want this thing to work.  Oh yeah and how is the best way to clean out an old dirty gas tank?

thanks.

[Breadfather]

You know what?  Now that I look at it, it does look like someone added the 2nd tank on the drivers side.  The bed on that side does not have the "recess" that the passenger side does.  So now that that is answered, lets get this thing working again.

[bake315]

how is the best way to clean out an old dirty gas tank?

Honestly, if it's really bad, you may be better off just getting new tanks.  Got my poly tanks from Raybuck Auto Parts..

They're polyethylene tanks, which mean no rust, and they are USA made.

http://raybuck.com/i-6698391-1973-1981-chevy-gmc-pickup-short-wheel-base-16-gallon-tank.html

[Breadfather]

I am not sure what classifies as "really bad" by it seems to have a brownish film in the bottom.  I like the idea of poly tanks, so that my be an option for me.  what I am most concerned with right now is how to hook everything up so it all works properly. would it just be easier to get the switch and new valve set up?  I don't mind manually switching from tank to tank i just want the look to appear stock and the gauge to read correctly.

[VileZambonie]

You can pick up  dual tank switch and bezel as well as the selector valve pretty cheap. The rest is just wiring it up.

http://forum.73-87chevytrucks.com/smforum/index.php?topic=9072.msg60482#msg60482

[DnStClr]

There was a thread on here a couple of yrs ago with a pic of the dash mounted push/pull.
 http://forum.73-87chevytrucks.com/smforum/index.php?topic=24701.0