sealing fuel leaks

[Bron5on]

Hey guys, started my 1.6 mpfi converted sierra for the first time today (whoo hoo!) and found a few fuel leaks. Namely the fittings in my surge tank and the join between the hard line and the flexy one that runs into the fuel rail. They're done up pretty tight so is there anything like plumbers thread tape i can use that is suitable for fuel applications??? I'm keen to take it for a drive to see how it goes but with fuel dripping down one side of the block and a manifold with no exhaust on the other (yes it's loud!) i'm sorta relunctant to push my luck. I'm kinda allergic to the extreme temperatures caused by the combustion of highly flammable liquids!!

Cheers in advance!

[mrw82]

can you get a pic of the leaking fittings? different fittings require different methods of sealing.
a tapered (bsp) thread uses thread tape to seal as the thread 'binds up'
a parallel thread uses a copper washer or dowty seal
a flared pipe does not use any sealant as the flare of the pipe is pulled up onto the taper of the fitting as the nut is tightened, if the pipe sealing surface is scratched, pitted, damaged it wont seal and the pipe should be cut and reflared.
if its just a hose onto a piece of pipe make sure its the right size hose, sure a larger hose might clamp down but has a high chance of leaking and/or blowing off.


Mark.

[nicbeer]

on the straight pipe u may need to flare the end like a brake hose

[Bron5on]

Thanks guys, got most of it sorted for now. The surge tank was leaking around the threads, some thread tape soon fixed that. The main concern was the join near the engine and yes it is one of those flared connections. The hard line and flexy fittings on the end (between manifold and fuel filter in back) are exactly as they came out of the donor car, no cutting and shutting was done, just a slight bend here and there and drilling holes in the rear floor to accomodate the new line. It was leaking around the top of the thread so I undid it, applied some thread tape and retightened. Seems to have done the trick but i'm treating it as a temporary solution. It was enough to get me out on the road for a test drive. If anyone is considering a 16v transplant, do it! Farking loud with just the manifold and no exhaust but sounds like an absolute monster! (think WRC car!!) Just have to tidy it up now! Cheers guys!

Bronson

[Ridge]

what sort of thread tape did you use? if it is not resistant to fuel it will melt and cause all sorts of problems cleaning it out.

[Bron5on]

Yeah I soon realised that!! I removed the thread tape (which was already starting to break down) and applied loctite 567 thread sealant. supposed to be good for both flammable liquid and high pressure applications. Haven't tried it out yet as I thought I'd give it a couple of days to cure. The excess which was forced back out when the thread was tightened doesn't seem to have dried at all but maybe that's just how it is?? I'll start the car tomorrow once the new extractors (sierra ones with modded flange to fit 1.6) get bolted on and see how it goes.