1987 Chevy Silverado 4x4 - Leaking Gas out the top of the Gas Tank with Key On

[Mike Phillips]

1987 Chevy Silverado 4x4 - Leaking Gas out the top of the Gas Tank with Key On


Last couple of times I drove my truck I thought I smelled gas?  This morning after driving to work, again I smelled gas so I started looking around and found the leak.  When looking down on the gas tank, in-between the cab and the bed, I could see fresh gas.

If I turn on the key, I hear the fuel pump, (inside the gas tank), working and then I see gas seeping out onto the top of the gas tank.  Here's a few pictures to show the location and the leaking gas.







I've never removed a gas tank out of a truck this new.  I've removed the gas tank in my 1975 Jimmy, it was in the back of the frame. 


Question?

Has anyone removed a gas tank like this before and do you have any idea what it could be that is broken or leaking so as to be pumping gas out of the top of the tank?

Ugh...

[spanky1205]

My first thought would be to check the fittings that go into the top of your tank.  They are probably leaking while under pressure but stop when the pressure is turned off.  FWIW I have heard it is easier to remove the bed from the pickup rather than trying to drop the tank.  Personally the only fuel tank I have ever worked on was in a car, after doing that I will be trying the bed option if I do anything to the fuel tank in my truck.

[zieg85]

Let me go out and take a picture of what you will find on your 87 BRB

[zieg85]

Here is what you will find.  Could be a hose, connection or even a crack in a rusty line that is built in the sending unit assembly.  Dropping the tank underneath isn't that bad since you are higher than a normal truck, just get the gas level down as low as you can before lowering...

[rich weyand]

Yup.  And while you are in there, you might as well replace all three hoses over to the other side as well as the hose clamps.  These hoses cross over both exhaust pipes getting to the tank selector on the passenger side frame rail.

Note the double clamp on the high-pressure fuel line.

Once the tank is down, you should be able to cap the end of the fuel line and then power the fuel pump long enough to see where the leak is.  That may tell you that you need to replace the sender unit as well.

[Mike Phillips]

Hey thanks everyone for all the quick input...

Here's the picture of the top of the tank by zieg85, I uploaded it to my gallery so I could insert it...



Ding dang... I just filled this truck to the top so it's completely full of gas.

Taking the bed off almost sound more inviting.  One thing I've learned about this truck since I bought it.  Although the previous owner did do a lot of great upgrades, it does look like it was re-assembled using old, worn out parts.  Like the belts and hoses for example.  I think it's safe to assume most of use on this forum replace everything when we rebuild a truck.  I mean heck, while it's all apart it only makes sense.

Being Monday, I won't have a chance to tear into this until Saturday, so I think I'll cross my fingers, drive it home and borrow the wifey's car the rest of the week. 

Ugh again...

[Mike Phillips]

Let me go out and take a picture of what you will find on your 87 BRB

Thank you sir!

That helps a lot.  Now I know at least what everything looks like.

The gas gauge doesn't read correctly since I bought this truck.  When full it's just below the 1/2  mark on the gauge and when empty it's just above the 1/4 mark on the gauge.

Guess it's time to look into this also.

[rich weyand]

Sounds like a broken resistor on the back of the fuel gauge. 
http://secure.classichq.com/RESISTOR-CONSOLE-FUEL-GAUGE--P816.aspx

[454Man]

Dude your truck looks Awefrikinsome! Hope you don't mind me asking. What wheel and tire combo that is?

What's under the hood??? If you have to ask maybe we shouldn't race...

[Mike Phillips]

Dude your truck looks Awefrikinsome! Hope you don't mind me asking. What wheel and tire combo that is?

What's under the hood??? If you have to ask maybe we shouldn't race...

Thank you.  What's even better is my wife Stacy found it for me.  Got love it when your wife finds you your new truck.

I'm a total big block Chevy guy but this thing came with a 350 and it runs so darn good it's a shame to have to remove it and replace it with a BBC but that's what's on the menu.  Just have to wait till spring/summer of 2014, too much going on in life to do it right now.

See this thread...

http://forum.73-87chevytrucks.com/smforum/index.php?topic=26508.0

[Mike Phillips]

Looks like I'm unbolting the truck bed starting Saturday morning.

I'll take some pictures in-case anyone else ever has to do this type of project into the future.

[rich weyand]

One good part of taking the bed off: you can test it in place.  Just turn the key on and track the leak down.

[frotosride]

I haven't had my bed off in over a year but it sure spins the tires wthout that weight on them. I think that I had a car port at the time so I just took out the light and placed on old jack pole over it with a come along... Thinking back..man was I lucky!

[Mike Phillips]

One good part of taking the bed off: you can test it in place.  Just turn the key on and track the leak down.

That's a good point.

I looked under the bed, looks like an air wrench will make quick work of removing the 8 nuts that hold the bed on.  Haven't looked to see what I have to do to remove, loosen or unplug any wiring loom.

Someone said to make it easier to remove the rear bumper, I'll look into that too.

Supposed to be sunny tomorrow so I'm going to start in around 8:00am

Wish me luck!

[Irish_Alley]

you should only have to un-bolt the fuel nozzle there might be a ground also (on my 94 there was) then a plug under the tail gate for the tail lights along with the bed bolts. the bumper i never took it off but either way you have to lift the bed up enough to clear the tires. dont have to remove it all the way just a couple feet back and let her rest on the bumper and tires. this is what i did with my 94