Auto Trans Fluid Leak

[special-K]

My '95 K2500 Suburban is leaking atf and I'm having a hard time locating where from. What I noticed is fluid on the ground behind the right front tire. I look into the well and I can see it is damp toward the rear, but the inside face is wet, so are the trans lines running along the engine, the front of the starter, and forward of the r/f wheel on the little brake box on the outside of the frame.

I run the truck and see nothing spraying, dripping, or seeping. Most only happen under pressure. I suspect the trans lines. First, because these trucks have issues with lines rusting out. Second, because the lines look clean and great everywhere but along the area where it is wet. There are patches and lengths with surface rust. Also, this is where they are held tight together, which I can see causing corrosive crap held between. The lines are also fairly level there. Third is all this leaking is forward of the transmission, so the trans lines to radiator are the only place I can think of trans fluid being that far forward. I figure on patching that length in on both lines first.

I hope that's it. I came here to see if maybe someone else had the same problem with a direct route to the problem. In one way the lines seem the obvious problem, but in another it doesn't seem right. That's because of where and how I see the fluid hitting. It must really spray out of there when driving. I just noticed the wet spot the other day. Fluid level is still good. Any help would be greatly appreciated

[diveplane]

good thing to try do is place your truck on level ground ok, then get a big white sheet or card board box cut it open spread it out under engine and tranny, leave over night look for oil spots on it next day, the trace the drips up from
stain , might lead u to the leak better.

[diveplane]

clean your transmission up with gunk gel, might help u trace leak better as well, i did mine great product.

[special-K]

That would work, but that's how I discovered the problem, one major spot in that strange place. And the lines where I said could be questionable don't have droplets like other places. I am seeing them over a long area. I did spray brakleen and drive to town and couldn't tell anything. I didn't have much in the can. Going to do a good cleaning to check. I have a sneaky feeling it is at the radiator because that is as far forward as the fluid goes and it is wet at the front of the frame. I think it drips behind the wheel from running out the frame. But trans lines are clean and dry up front.

[Palf70Step]

look at the point the croos over one another. I have had several that vibrations cause the lines to rub and wear a small hole in one or both of the tranny lines. From the area you are describing that is normally where they cross over one another.

[special-K]

That's the area I suspected. But if it's leaking as much as it appears, those lines aren't dripping wet like areas hit by the leak. Also, the clamps that hold them together are still properly fastened.

I cleaned it up real good before going up to the corner for some things. There were drips all along from front to behind the wheel... most behind the wheel, which is coming off or out of the frame. This got me really suspecting at the radiator. Back home (about 5 miles) and very wet all over. Dripping from that ABS box on the frame. I see where for some reason there is 3-4" of rubber line between radiator and hard line. Not sure why, unless just to give more length to connect easier. There are two clamps on the line side with the end one clamped just before the threads of the hard line fitting. If there's anything inside that rubber it's a piece of hard line too small to clamp to. Feels soft there. I'll get into it later, but I guess there is a fitting into the radiator with a length of line the rubber is clamped to. I suspect this has to be the culprit.

[special-K]

Reconfigured all that, cleaned it up, went into town (about same distance), back, and looks like that was it. Man, just a little annoyance, but until I found it I had no idea if it would start puking heavy and leave me stranded... so didn't drive it.

[Palf70Step]

Glad to hear you found the issue.

[Mr_Rich]

Glad you found it. I was wondering where the leak was myself since it became a mystery the way you described it. Remember that a trans operates on oil/ fluid pressure 2X that of the engine. You definitely want a tight system there. Engine operates on about 40-60 psi normally and a trans operates on 100-120 psi.

[special-K]

Yeah, and fluid is what, like 4w? When they leak they blow, not seep. This was a very minor thing causing the problem. Basically just a clamp that could have been tighter. It lasted about a year. Put an engine in it last summer and the radiator blew on the test drive.