Tying Saddle Tanks with a T?

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BigDaddy72

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You would probably have to run an equalizer tube between the bottom of the two tanks to prevent this. The tanks should draw at the same time.


How did I miss this??

Yep kinda what I was thinking.
 

WFO

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I’m trying to not use any hose clamps or rubber fuel line on the saddle tank set up.

The “pair” of switching valves I bought are plastic metric not sae.

So I’ve been looking at manual valves and I really don’t want to go that route.

My question:

Has anyone used a “T” going to the fuel pump and just draw fuel from both tanks at one time??
Back in 83 the valve went out on our 80 C20 company truck while we were workin out of town. I put a T on it, and it drew from both tanks. If I filled one tank it would eventually equalize with the other one.
It stayed that way till we finished the job almost a year later.
 

BigDaddy72

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Back in 83 the valve went out on our 80 C20 company truck while we were workin out of town. I put a T on it, and it drew from both tanks. If I filled one tank it would eventually equalize with the other one.
It stayed that way till we finished the job almost a year later.

So what your saying is: It pulled equally from both when they were full.

If you had a 1/2 tank in the both of them and filled one tank full it would pull off of the full one, until it was at 1/2 then start pulling off the pair again?

Did I understand that right?
 

Markmx6

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On my 78 the left tank lasts a while and then when you switch to the left tank it runs out very quickly. Switch back to the left tank and you have half a tank again. Either the return line to the right tank is clogged or just not switching over.

I guess I am not certain what you are trying to do that is different from the factory setup. You want two tanks with fuel level senders and one gauge? I am missing something.
 

BigDaddy72

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On my 78 the left tank lasts a while and then when you switch to the left tank it runs out very quickly. Switch back to the left tank and you have half a tank again. Either the return line to the right tank is clogged or just not switching over.

I guess I am not certain what you are trying to do that is different from the factory setup. You want two tanks with fuel level senders and one gauge? I am missing something.


I was asking if anyone had bypassed the fuel tank switch/valve with a T and if so what were the results.

Basically pulling off 2 tanks as if they were one.
 

WFO

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So what your saying is: It pulled equally from both when they were full.

If you had a 1/2 tank in the both of them and filled one tank full it would pull off of the full one, until it was at 1/2 then start pulling off the pair again?

Did I understand that right?
I guess it would pull off the one that had more gas, since it would have more head pressure. Not really sure though.
What I'm sure of, is that if I had both tanks half full, then filled up one and drove a short distance and parked it for a while, I would end up with both tanks almost 3/4 full.
Then it would draw off both equally.
It would also eventually equal out on the highway if I filled one before headin out.
 

BigDaddy72

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I guess it would pull off the one that had more gas, since it would have more head pressure. Not really sure though.
What I'm sure of, is that if I had both tanks half full, then filled up one and drove a short distance and parked it for a while, I would end up with both tanks almost 3/4 full.
Then it would draw off both equally.
It would also eventually equal out on the highway if I filled one before headin out.


Thank you very much for the information.

Did you ever have fuel surge? “Like the engine would be running out of fuel”
 

dsteelejr

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I haven’t done it to prove it but I think it will take the path of least resistance. That’s why I think it will empty one and then try to pull from the empty one.

That would most likely be an issue. I think a better idea would be to run a line between both tanks and equalize them.
 

Michael Benardo

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I’m trying to not use any hose clamps or rubber fuel line on the saddle tank set up.

The “pair” of switching valves I bought are plastic metric not sae.

So I’ve been looking at manual valves and I really don’t want to go that route.

My question:

Has anyone used a “T” going to the fuel pump and just draw fuel from both tanks at one time??
I wouldn't. You would have to fill both tanks at the gas station, which would you would have to do one at a time, as the gas hose will not reach to the other side, or else when one tank runs dry, you will be "out of gas", as that empty tank will be just like having an open fuel line - no gas will be drawn up from the full tank, as it is easier for the fuel pump to draw air than it is to draw liquid.
 

Nuckollsr

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I have '87 GMC R1500 with saddle tanks. I put check valves in each pump's output line then Tee'd them together to drive supply line to the carb. Select tank by powering up either pump. Works good, lasts a long time. I think these pumps have check valves but the extra valve doesn't hurt. Was really happy to get rid of that plastic octopus of a selector valve. Of course your pump switch also needs to switch senders to the gage. Check valves are about $5 each.

For a time, I just wired the left sender to the gage. Ran right tank 'til dry then switched to left where I had a more-or-less heads-up on fuel remaining.
 

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