Fuel Leak 6.5 TD HELP

[Bully44]

Hey Guys,

I am new to this site as well as Diesels in general so I am hoping for some help. I bought a 6.5 TD a few months back from an asphalting company that had it sitting for the past 2 years. It has 171,xxx miles. Now i put in a new batteries, new glow plugs and glow plug relay. I had it running but I noticed a lot of oil on the Turbo. So I put in a refurbished turbo in and then it wouldn't start. Fuel started to leak somewhere out of the rear block. took off the intake and there was no fuel sitting in the valley. There is also no fuel to the injectors. I swapped out the fuel filter and still the same issue. Please help!! I do not know what else to do.

[Yukon6.2]

Hi
The first thing you need to tell everyone is what truck you have.
Year,trans,model and any modifications done.

[JohnC]

What he said, and, look for two short rubber hoses at the rear of the valley where the fuel lines duck down behind the firewall along the top of the bell housing.

[jggiedeman]

I just pulled those two short pieces off. They were definitely not made for diesel fuel. I made some brass barbs to install in short pieces of the cloth covered hose and viola - no more leaks.

Seems the rubber that was used did not hold up past a year. The small clamps actually cut into the rubber.

[Bully44]

Wow I am an idiot. Sorry, I have a 1998 GMC c3500 with the 6.5 TD. I have not done any mods because I am still trying to get it to a dependable state. I do not know what trans. However, I have already checked those two rubber hoses and it does not seem like they are in bad shape

[Robyn]

Run your hand down under the fuel filter/manager

My bet is it will be wet with fuel.

There is a drain hole in the rear of the valley...fuel will run out and then out on the ground.

The fuel managers are notorious for rotting out from having water in them.

I like the Racor 230R2 filter.
Has a water bowl you can see wasssssup and a drain.
2 micron filter...will keep the DS4 happy and pass plenty of fuel.

Easily mounted up front by the ABS unit on a custom L bracket.....Use a barb and connect the hoses to extend them up front....secure well to AVOID chafing.

Remove old filter and toss it...go find it and toss farther..
Remove the water drain hose that lays in the valley.

Check it out and let us know what you find...
The other possibility is a leaking Plug on one of the rear injectors (Rubber cap plug on the end nipple of the rear two injectors) these usually spray fuel all over if they leak..

[phantom309]

It sure is difficult to diagnose a leak if you don't get some on your fingers and smell it and taste it
Diesel and coolant sure look and smell and taste way different,.
Lotta good experienced people here more than willing to help but only as good as the person being instructed to check and replace parts.
But sometimes its a "magic" leak which can be traced back to not doing basics,..
Apology needed in this case from OP inmho.

[JohnC]

Na, it's all my fault. When he posted this picture and said it had no smell, I should have known it was coolant. (too much surface tension for fuel)

[Robyn]

Well ya could have fooled me....

[snarl]

My diesel is green. I thought it was atf.

[JohnC]

Red fuel is off road fuel.