Front Starter support Bracket, is this it?

[Robyn]

If the fuel pickup was the same shape and depth from the rim that sits in the top of the tank it should be fine.

Personally...

I would drop the tank, remove the pickup and check it all out.

With the rig stationary ... 5 gallons of fuel should be quite sufficient to satisfy the pickup and not allow air to suck in.

Check it now and get it right, lest thee might find ones self in deep do do some cold lonely night along the interstate...with no fuel flow...


Summer in the driveway is far and away better than the edge of the road on a dark night....

Been there done that trick



Good luck

[DmaxMaverick]

If starting with adding 5 gallons doesn't work, but adding another 5 does, something is wrong, still. The sender is not picking up fuel as it should. Adding 2 gallons should get you started, let alone 10! This assuming you are parked relatively level. Any grade involved will certainly change the results. Despite everything else, this is a good thing to know, now, as opposed to Robyn's scenarios. As my old grandpappy (RIP) used to say, keep the top half full, and the bottom half will never let you down.

[DieselDavy]

As Robyn & DMax know, this tank is relatively flat on the bottom. "Under trunk" type tank, no bowl for the pickup to sit in. Just a couple of gallons should have been enough. The Tahoe was on my lift during the repair and with the way the short frame of the 2 door swoops up at the back, there is a slight tilt in the way it sits on the lift with the front leaving the floor a few inches before the rear. With the way the tank is shaped, it could cause a little fuel shift, but not enough to keep 5 gallons from covering the pickup. Robyn, you are correct, I need to get it back on there, drop the tank and see wassup! Our Lucerne is next on the lift for a new transmission so it'll have to wait a couple of weeks, but I'll have to do it. The aggravating part is that I set the old and new pickups side by side and they looked equivalent. Original equipment TS1012 fuel sock looked like it should sit in the same spot as the old pickup.
I don't know how it works but is it possible the bypass hose could have a hole in it and it's somehow picking up air? It looked like it was 'tie wrapped' to the main tube and should be picking fuel up very close to the bottom of the tank.
Anyway, thanks for holding my hand as I went through this process. Removing the tank the next time will be much easier!
d

[Robyn]

Tie wrap ?????

Get a stainless steel hose clamp on the bypass hose.

A tie wrap is no where near dependable enough..

[DieselDavy]

Robyn,

"Tie Wrap" term was used as a generic term here for some sort of fastener. I have to be honest, I don't remember exactly what fastener was used. I should have taken a picture of it....

I can't work on this right now as the Lucerne is on the lift and it's transmission is in the back of my truck today. (taking it in to get it remanned) Once this is project is completed, I'll try to refocus on the Tahoe.

I do what to say thanks to those contributing to this tread. Your advice is truly needed and appreciated!
Dave

[Robyn]

Ahhhh copy that

[More Power]

but is it possible the bypass hose could have a hole in it and it's somehow picking up air? It looked like it was 'tie wrapped' to the main tube and should be picking fuel up very close to the bottom of the tank.

A little trivia... GM designed the fuel-return piping in the tank to minimize aeration of the return fuel, so they had it return closer to the bottom of the tank rather than splash down from the top.

A leak in the fuel-return line from the engine on back would/could make a mess, but a leak wouldn't introduce air into the fuel line that feeds the engine.

[DieselDavy]

I'm in my office now so I can't look at the sending unit I took off....but how does the fuel sock 'bypass' work. Could there be something wrong there that allows air into the system?

[DmaxMaverick]

I'm in my office now so I can't look at the sending unit I took off....but how does the fuel sock 'bypass' work. Could there be something wrong there that allows air into the system?

No. The inlet pipe is fixed, just above the level of the bottom of the sock. The sock ONLY screens the fuel prior to inlet, diffusing and reducing the velocity of the inlet fuel. The (sock) "bypass" is merely a spring loaded gate that opens if the fuel demand exceeds the allowance of the screen.

The fuel inlet BYPASS valve (if it has one), is a different relief valve in the suction pipe, about 1/4 way up the fuel level, that opens if the normal fuel inlet becomes nearly completely obstructed. The only consistency I have identified with their application is mostly limited to high reliability vehicles, such as CUCV, ambulance and fire, but some civi's had them.

[DieselDavy]

Given DMax's comments, there may be nothing wrong with my setup. With the slight angle my 2 door sit at on my lift and me pumping about a gallon through the system after to clear the air, I may have been sucking air off the bottom. I'm going to drive it for a while and see how it acts.
Thanks to all for your help!
Dave