LB7: Diesel Leak after injector replacement

02dirtymax

Member
Jul 3, 2009
149
0
16
Ohio
Any tips on finding a diesel leak after injector replacement? I just replaced mine due to fuel in crankcase- balance rate were fine. Now I have a stream of diesel coming out the rear main seal with the new ones. I plan on hooking up EFI Live to see if I see something retarded on one injector to have somewhere to start. Other than that, is my only option to pop the valve covers and run it? Hopefully I am retarded and find something loose on the PASSENGER side.

Truck runs great, I have a lift pump but it didn't seem to have trouble building prime which makes me suspect a return seal.
 

wes06dmax

New member
Feb 23, 2009
1,367
0
0
37
South Central Kentucky
Did you tighting up the fuel return line good I mean all the allen heads that goes to the injectors and most important the 12mm bolt at the end of the line that goes in the head I had this problem the other day after changing the nozzles in a lb7
 

delong_1

<< my work
Dec 5, 2008
1,282
0
0
38
Arvada, CO
i agree with the return lines being loose, also just to make sure befor you pull the valve covers take a really good look at the fuel rails and down in the valley. any leaks in the valley drain down the back of the motor and around the bell housing. hopefully its an external leak.
 

Vrabel

TOYAHOLIC
May 22, 2008
3,434
0
0
57
Hewitt, NJ
its a suck job, but run with vc's off. You did torque feed ines to spec right. over tightening will strech roll pin and cause them to leak (Been there, done that). but running with vc's off and unplugging fpr, made it plain and simple where the leak was.
 

ZeroGravity58

Well-known member
Mar 23, 2008
1,401
51
48
38
Maryland
any leaks in the valley drain down the back of the motor and around the bell housing. hopefully its an external leak.

Check your hoses and FICM bolts. If you have a lift pump it will push plenty of fuel out. If theres not fuel in the oil then theres no internal leak.
 

02dirtymax

Member
Jul 3, 2009
149
0
16
Ohio
I'm retarded. Ran it with the valve covers off and didn't find anything and then looked around harder and found a cracked return line on top of the motor (off the FPRV). I have some diesel in the oil from before replacing the injectors so it is hard to tell if I was getting anymore in. Sucks I did all that extra work but at least I know I don't have any leaks under the valve cover and I would have removed most of the stuff on the drivers side to replace the fuel line anyways. I looked up around the back of the engine when i first saw the leak to see if it was coming down and around and didn't see anything-that stuff is sneaky! I should have stepped away and thought about it some more before tearing back into it mad and tired. I'll get it buttoned up after work tonight.