Kriev

Hi everybody. I discovered a leak from the frame. Could this be a line? At times it will leak profusely, at others it will drip. (Depending on the slope?). It continues to drip for a while after it turns off. (Fuel that has been pumped into the line?) I'm wondering where exactly the lines enter the frame and how is the best way to inspect the lines. (Disconnecting them I would guess.) I'm guessing its coming from the front of the vehicle rather than from the tank area of the vehicle. I don't know anything but i've been familiarizing myself with a vacuum diagram. Thank you for reading!

,Kriev

Kriev

I did not mention the air pressure that is released when I open the tank cap.

,Kriev

wyoming9

iTrader: (1)

The lines should run along the frame.

Then no telling what someone may have done I have seen some strange things on these trucks.



. I am guessing it is your return line if it was your pressure side it would spray out with pressure. Leaking gas is really not a good thing.

this can be real interesting to fix rusted fittings things breaking .

Good luck.

scope103

This is a "good thing." It means your vented cap is working, and you don't have a hole in the tank (happens all too often in the rust-belt; they rust through the top, so they don't leak all the time.)

I agree that it sounds more like a return line. But as wyoming9 points out, the lines run alongside the frame, not inside, so the leak shouldn't be that hard to find by just sliding under the truck. IF you find a leak "from" the frame, back up to find where a fuel line is leaking into a hole in the frame.

And do take care of this; sitting in a pool of burning gasoline could run your whole day.

Kriev

I'm feeling its the return line too. I found a similar thread from a few years back. His leak is identical to mine. They're talkin' about the charcoal canister going into the frame. I'll do my best to feel that area for leaks. If i can't find anything there... I'll think about how to get the line out of there so I can inspect and replace it. Where does the return line start and terminate?

Kriev

I'm glad that the tank is all intact. Its uplifting that the lines are outside. Because I'm stressing alot over how i'm getting these imagined lines from inside the frame. I'll look again, very closely this time, at the lines alongside the frame. I thought those would be some brake lines... Thank you's!

,Kriev

Kriev

I'll have to run the truck to find anything leaking. The thing with checking is that it does not leak everytime its running. Could this be because the return line is not always filled? Theres 3 lines alongside the frame. Theres 2 little 1/4" tubes and one 3/8" Which is the return line?

Kriev

I'm thinking a vent is blocked and the pressure in the tank is causing a leak. Remedy: loosening the gas cap when driving.

scope103

The fuel cap is part of the system keeping you alive. If you get into a collision, even a light tap, having a loose gas cap could allow a big spray of gasoline.

But that's clearly not the problem. The fuel pump is in the gas tank and pressurizes the fuel line to about 45 psi (a little lower once it reaches the FPR). If you pressurize the gas tank you might get as much as 0.5 psi before the tank blows up like a balloon. And that is simply normal.

That pressure in the tank is vented through the canister to capture the fumes. Since it's a vent and doesn't extend down to the level of liquid fuel, you should never have liquid fuel in the vent line.

You probably have a crack in the fuel return line. A crack in the pressure line should leak continuously, but the return line is near-atmospheric. So the crack might close up until you shake it a bit.

You don't need the truck running to test this; just the fuel pump. Jumper FP to B+ with key-on.

Kriev

Thank you all for your input, greatly appreciated here. During the winter here in the great white north, I had no leaks. And as soon as a warm day came, the dripping from the line started again. Just a matter of finding that pesky leak. My girlfriend's dad said, "you might to wait until it gets worse so then it will be easier to find." It seems worse now, hopefully I can rectify this situation soon.

,Kriev

scope103

You might want to look at your entire EVAP system. http://personal.utulsa.edu/~nathan-b...76evaporat.pdf The EVAP system has to deal with more fumes in warmer weather. If your TVV is broken (all too common), the vacuum might not get there from the throttle body, the fumes aren't emptied from the canister, and sooner or later all that gasoline has to drip out.

Terrys87

iTrader: (1)

I have seen several times where the "J" line on the fuel pump assembly is clogged. Usually the return line is clogged as well when that happens. To check the return line I extend a hose from the return line under the hood and with the pressure of my lungs, I should be able to clear it. If I cant, I take a gear oil bottle cap and use it as a funnel to fill it with rust dissolver and add it to a little at a time over a few days. With the fuel pump assembly off I then use an air hose to flush the line.

To just try and clear any clogs with high pressure you risk blowing the line or compressing the clog.

The fuel pump assembly "J" line I do about the same thing only it is a little easier using a small wire and air hose to get it clear. Once you get the clogs removed, you could have some one to block one end of the line and using low pressure air to check for leaks on the return line.

I have more information on the 88 Runner below on my signature on the first post and page for fuel tank systems.