Snubber, needle valve, or both?

[leathermaneod]

Hi all,

So shortly after getting my Fuel Boss lift pump and big line kit installed a few months ago I noticed that I have a 1-2 psi needle bounce in my autometer mechanical fuel pressure gauge. I am using a snubber from Geno's and my pressure tap is located on the filter canister outlet. As you can see here.

The items are from left to right, Female JIC end of Vulcan Universal Fuel line(brass), Male JIC to NPT adapter(silver), Geno's snubber(brass), Street 90 from Ace(brass). This setup comes out of the tapped 90 that attaches to the bottom of the fuel filter canister. 

 

Anyway, I've dealt with the needle bounce for this long, but I always regretted not installing a needle valve so that I could turn the gauge supply off in an emergency. The more I thought about it, I realized that adding a needle valve would probably help with my needle bounce and make my gauge last longer. So I got one from Vulcan. My question is, should I used the snubber and the needle valve? or just the needle valve? The only thing that concerns me about using both is that assembly is getting long and heavy where it comes out of that tapped 90. Also, does it matter what order I put the items in? I am also looking for recommendations on thread sealant for the NPT threads. I have used this 

and this

in the past and both seem to be ok. The 545 is the purple liquid stuff and I always feel like I need to let it sit overnight before running fuel through it. The 567 is more like regular pipe dope. I always figured the purple liquid stuff was safer for a post filter application than pipe dope just incase some got to the injectors. But I was told when I did my Fuel Boss install that regular white(PTFE or whatever its called) pipe dope was fine for that. I would like to know what you all think and normally use. 

Thanks in advance!

Edited March 30, 2016 by leathermaneod

[TFaoro]

I always use the white teflon tape when installing pipe fittings.

 

I would use both. As for the order, I don't know if it makes a difference, but I like mine to be before the snubber. The more damping the better for the gauge. 

 

As for the weight, I wouldn't worry. Support it as best you can with zip ties and roll on. You'd be surprised the abuse those things can take. 

[leathermaneod]

Thanks for the tips! I hadn't thought of Teflon tape. You think that's safe to use in a situation where there is no filter between it and the injectors? I thought I had read of guys having trouble with pieces of it breaking off inside though...I guess it should be ok if I keep it back a few threads...

[KATOOM]

I on the other hand am leery of Teflon tape because its easy to create a leak if you ever find yourself turned too far and have to back it a 1/4 turn or so.  And its easier to get shards of it in the fuel lines, which would be bad.  But I guess that said, if someone is incompetently unsafe using either both thread sealant and Teflon tape, you're going to have problems.

 

And I do agree that multiple snubbers is a good thing.  I have two.....   If you want to run a needle for emergencies then thats OK too.

[notlimah]

I think with a mechanical gauge you can get away with just running either a snubber or needle valve. It won't hurt running both though.

 

I personally only run a needle valve, and see very minor needle swing if any. I could always close the needle valve a little more to get rid of it if I wanted.

 

I'm also a big fan of 545. Diesel won't eat away at it and I feel more confident in the liquid creating a more solid barrier then the tape but that's just my opinion and ymmv. BUT, that 545 is expensive and if you already got it, might as well use it!

[Buzzinhalfdozen]

I use Teflon tape on most fittings mainly because it's fast and less mess if you have to take it apart. However I've had good luck with the liquid type and regular white dope.

[Cowboy]

I use non-hardening gasket maker on any diesel/oil fittings.  I've used it a fair bit with different systems, some admittedly shady things to get over the hump and have never had an issue.

[leathermaneod]

Wow thanks for all the replies! Those of you that said you like the 545, how long do you wait for it to dry before running fuel through the system?

[notlimah]

I'm not sure I wait a specific amount of time. Usually by the time I'm reinstalling whatever I had to use the 545 on, it's looking like its gelling/hardening so I don't worry about it. As long as it's something I can access fairly easily, I wouldn't worry about it. Worse come to worse you could always get in there and add more of you were to have a leak.

[leathermaneod]

Well after my experience today I can not recomend regular pipe dope to anyone. I'm not sure why, if I didn't have enough or what, but I redid everything I had pictured plus the Schrader valve in the tapped 90 at the other end and I have multiple leaks. Like I said I'm not sure why, I didn't use a lot because I was trying to be very careful not to get any on the inside, but I did use plenty. Maybe it's just because the fittings are so small. So now next time the weather is nice I've got to tear it apart again. I guess I should have just used the 545 to begin with, but I like the idea of pipe dope staying somewhat pliable, where the 545 gets very hard. Anyway just figured I'd throw this out there as a caution. 

[leathermaneod]

Edit: just wanted to say that my post above is not meant to offend anyone who mentioned pipe dope and I do not want to sound ungrateful for anyone's input. I was just a little annoyed with my leaks when a wrote it lol 

 

so I decided to get that stuff back apart right away while the weather is still nice. When I took everything apart I noticed that it literally looked like the fuel was dissolving the pipe dope. I got it cleaned up and back together with the 545. That stuff is great to work with btw!  Had forgotten how nice it is. I didn't re install it yet though because the bottle says it fully cures in 24hrs. Since I have time I decided to wait and be safe. 

 

I also forgot to mention earlier earlier that I changed my fuel filter at the same time. Went from a Baldwin pf7777 to a 7977. I also removed my fuel filter canister and cleaned it. It had a TON of sediment in the bottom! I tried to remove the fuel heater but it didn't come out easily and I couldn't find instructions so the whole thing got hosed out with brake cleaner and then compressed air. Then I used a rag on a screwdriver to reach all the way in the bottom to get the stuck on stuff.  Is the fuel heater connector supposed to have some kind of gasket where it mounts to the housing? Mine doesn't and it has a decent gap on the bottom where dirt can get in to where the wires are...

[TFaoro]

Teflon tape FTW! Haha just messin with you.

[Me78569]

I use the yellow teflon tape typically.

 

Little late to the party, but

 

[Buzzinhalfdozen]

I'm sure you checked but was the dope compatible with petroleum? I'm pretty sure most are. I was fighting a 1/2" fitting recently that tape and the liquid wouldn't seal, doped it up and dry ever since. 

[leathermaneod]

Dont you guys find the Teflon tape a pain to work with on such small fitting? I mean there ends up being a lot of extra even on air hose fittings. And what's the difference between yellow and white?

 

I actually did not check to see if it was compatible with petroleum. I bought the stuff when I installed my Fuel Boss because it's what Rich at GDP recomended. I just made sure that it was PTFE because that is what he specified and I have had no problems with it. I used it on the 3/8 fittings where they thread into the pump. I'm guessing there just wasn't enough of it on these tiny fittings.

Edited March 31, 2016 by leathermaneod

[notlimah]

Is there a reason you don't want to use the 545? It sort or seems like your making things harder on yourself since that will work and you already had it. 

[leathermaneod]

I did use it after the dope fail. I just liked the idea of the dope staying somewhat soft and pliable so that you can move it slightly. Where as the 545 gets rock hard and can't be moved once it's cured.

[Mopar1973Man]

Typically with brass fittings they are self sealing fittings. Rarely use any Teflon tape on engine fittings. 

[leathermaneod]

14 minutes ago, Mopar1973Man said:

Typically with brass fittings they are self sealing fittings. Rarely use any Teflon tape on engine fittings. 

Really? Even ones with NPT threads?

 

Also, random question. Finally got my edge comp today. I should have had it yesterday but they sent me an EZ. They got it taken care of very quickly though by overnighting me the comp without even waiting for me to send the EZ back. Anyway, when I first picked the comp box up, it kind of rattled like something was moving inside of it. I quickly realized that the plug port that comes out of the back moves somewhat in its hole(and whatever it is attached to inside). I made sure the screws were tight and they are. Is this normal? Or should I be calling edge again to swap it out?

 

[Mopar1973Man]

6 minutes ago, leathermaneod said:

Really? Even ones with NPT threads?

 

Yes. Like this... Screwed together and tighten no tapes or dope used. No leaks either.

Edited April 2, 2016 by Mopar1973Man