So, i've narrowed down my hard starts (again) to a diesel leak that's coming from my fuel pressure sending unit. To make things easy, let's assume I can't screw my fuel pressure sending unit in farther. Is there a thread sealent tolerant to diesel fuel? I have abstained from teflon tape, as gasoline eats away and gets clogged by it.


What can I use to seal threads on diesel?

 

Try this stuff.


Permatex® High Performance Thread Sealant

OEM specified. Formulated specifically for metal, tapered pipe thread fittings, High Performance Thread Sealant replaces Teflon® tape and pipe dopes. Cures rapidly to withstand 10,000 PSI. Perfect as a replacement for Vibra-Seal® pre-coated parts. Prevents galling and protects mated threaded areas from rust and corrosion. It is certified to ANSI/NSF Standard 61 for use in potable water systems.

Suggested Applications:
Stainless steel fittings, head bolts into through holes, oil PSI sending units/sensors, oil and coolant lines, intake manifold switches, rear axle fill plug, fuel fittings

 

Assuming you have good threads, Permatex #2 (non-hardening) also works well. It's been used in the oil patch as long as I've been around (and that's awhile )

Rusty

 

Strong second to what Rusty said.
You'll have no problem finding the #2 at any autoparts, the stuff Ed recommended while good may be harder to come by.
I have a farm diesel tank that seeped fuel, tried all kinds of different sealants for several years (could only reseal when the tank was empty, which I didn't really want either)
Permatex #2 finally fixed it, it's been at least 15 years without a drip.

 

Gasoil Teflon paste works well too.

Scotty

 

awesomeness. I will try this today or tomorrow, whenever there be time.