Replacing the fuel return lines - any tricks/tips?

[AJMBLAZER]

Noticed something oily all over the bottom of the truck starting around the engine. It's always leaked oil from the pan seals so I just figured that had gotten a bit worse, kept an eye on it and the oil level, and kept going until I got my new truck a week or so later.

Started to notice that after I drove it it'd pee a little of this oily liquid under the front of the engine and off the front axle. Not a lot, but it was doing it.
Realized it was diesel that was washing the oil smoodge off of the engine.

I had my buddy drive it around and I could see it dripping fuel off the front of the engine.

It sat at his house for a few weeks as his backup vehicle while one of his cars was being fixed then we brought it here...and it didn't leak at all. Sat for days and made no spots at all. Then I drove it some more and now it leaks a little.

Talked with some folks on another site and they said it was likely the fuel return lines. So I ordered Kennedy Diesel's kit and am about to dink with this.
Anyone have any hints or tips? Thoughts? I've been pretty lucky so never touched this stuff on my 6.2L's. Barely know where they are.
Figure probably a good time to do my fuel filter too.

[Robyn]

Pretty simple really.

The back two injectors have caps over the rear most return fitting.
The rest of the little lines connect from one to the other and then to the main return line at the front of the engine.

Some kits have a braided cover over the lines and do not require a clamp on each line fitting, while others come with clamps for every fitting.

The rear CAPS require a clamp on them. These are the little tiny constant pressure metal clamps. Use a needle nose pliers or similar tool to install and dont over squeeze them or they can lose their tension.

I prefer to install the clamps on the cap and then slide the assembly over the nipple.

The kits can come with the lines all cut to length and others come with just one long piece.

Make the lines just long enough that they can connect the nipples and then have a nice smooth arc. Not too short and not too long ya know :)

Connect the last line on each side to the crossover and your set.

Make sure the lines that connect to the IP return fitting are replaced too.

All this stuff gets hard over time.

The biggest issue is usually with the little rubber caps on the rear most injectors.

These tend to have the most problems with leaks when they get old.

The tend to crack and then leak.

This part of the system has a very low pressure as it is just the left over fuel that LEAKS by the inner parts of the injector that is returned to the tank.

Good luck

Missy

[Subzilla]

Just a thought: I've had the leaky end caps many times. What if we were to run a line from the back injector on the driver's side to the back injector on the passenger side to eliminate the end caps? Never tried it but have thought about it.

[DmaxMaverick]

Regarding the end caps:

These have been an issue, for one reason or another, from day one. I haven't had to mess with them for quite some time on mine, but I attribute that to dumb luck (which doesn't seem to work or more complicated/costly issues), more than anything else.

A few years ago, a friend was having the same issue, more frequent than he cared to discuss. The simple/permanent solution.....soldered the damn things. No more caps. No more leak. If need be, the solder can always be melted out later. If you try this, be sure it is with the injector clean and free of fuel, OFF the engine, with the injector inverted, to prevent solder from wicking into the injector body. A few minutes invested and his leaks went away forever.

[AJMBLAZER]

Well, another update.

Finally had time to lay under it today and dick with it. The good news:

The fuel return lines and end caps look to be in good shape and are NOT leaking.

Which brings up the bad news:
Looks like maybe the fuel pump on the front p-side of the engine and the IP are leaking.
The fuel pump and surrounds appear nice and wet and the engine valley starting from the IP and heading back are nice and grungy and wet.

Awesome.:(

[NH2112]

Just a thought: I've had the leaky end caps many times. What if we were to run a line from the back injector on the driver's side to the back injector on the passenger side to eliminate the end caps? Never tried it but have thought about it.

I've done it before, I had several feet of the clampless return line but no new caps and the old caps were leaking. No problems at all with it.

[AWOL]

Well, another update.

Finally had time to lay under it today and dick with it. The good news:

The fuel return lines and end caps look to be in good shape and are NOT leaking.

Which brings up the bad news:
Looks like maybe the fuel pump on the front p-side of the engine and the IP are leaking.
The fuel pump and surrounds appear nice and wet and the engine valley starting from the IP and heading back are nice and grungy and wet.

Awesome.:(

I just went through that 2 weeks ago. I didn't know that at the very back of the intake valley there is a drain hole. The seal in my IP was shot and leaking fuel into the valley and it was then running down the back side of the block on the drivers side and then dripping down off the trans. At first I thought it was my return lines as well...I was lucky enough to have a extra IP laying around from a used motor and it happened to be good. It just sucked having the truck down for a couple days. Good Luck!

[AJMBLAZER]

I need it as a backup vehicle for a little while so it's just leaking and getting bad mpg now.

After that starts the search for a good IP building place and finding one that doesn't take me months to save for. The fuel pump I could buy right now...not so much on the IP.