Fuel pressure sensor leak

[KyFarm]

Put a HT383 in my 69 K10 and after running a bit installed a ProFlo4 on it. After driving a bit I’ve developed at small drip fuel leak from the threads of the fuel pressure sensor, tried to tighten the sensor and that didn’t fix it. Removed the sensor and checked threads on sensor and fitting, all look good.

the sensor isn’t built like it should take a bunch of torque and doesn’t have an o-ring.

It’s an edelbrock 3546 sensor with 1/8 -27 npt threads.

Does anyone know of a trick to get this sealed?

Tighten it until it seals or cracks? This seems like a good way to develop a crack later and burn your truck down.

Thanks for any help.

[Willshook]

NPT needs sealant; it won’t fully seal dry.

[KyFarm]

Originally Posted by Willshook

NPT needs sealant; it won’t fully seal dry.

Can you suggest a sealant that works on fuel lines?

[Willshook]

This is my go-to:

https://www.permatex.com/products/ga...-liquid-16-oz/

It’s fuel-safe; the key is not to apply it a bit higher on the thread and not on the tip of the fitting.

[Dead Parrot]

2nd on the need for sealant. Plumbers use sealant on nat gas NPT threaded plumbing and that is less then 1psi for most residential uses.

[KyFarm]

Originally Posted by Willshook

This is my go-to:

https://www.permatex.com/products/ga...-liquid-16-oz/

It’s fuel-safe; the key is not to apply it a bit higher on the thread and not on the tip of the fitting.

above you say NOT higher on the thread and NOT on the tip of the fitting.

I've always applies sealants higher on the thread and NOT on the tip, is that what you meant?

[Willshook]

Originally Posted by KyFarm

above you say NOT higher on the thread and NOT on the tip of the fitting.

I've always applies sealants higher on the thread and NOT on the tip, is that what you meant?

Bad wording on my part - "higher" to me on a fitting means closest to the hex.

You're right - bottom line is we don't want that junk in the fuel system.

[Orange Crate]

I can't see the electrical connector pins in any of the pics online so one issue to look at is if the sensor grounds through the case/body. Sealant could prevent good grounding. If the connector is two wire you don't need to be concerned as it will most likely be grounded at the FI ECU. If it is a one wire connector you might see some pressure discrepancies at the display, or calculations could be inaccurate.

[Willshook]

Typically, if it was grounded through the mechanical connection it would have NPT*F* thread, which does not require sealant.

[KyFarm]

Well, I have a bottle of Permatex 80019, it's less than a year old and I've tried to seal this stupid sensor twice now and same result each time.

Maybe my 80019 is a bad batch, it you drop a bit on a paper towel and let it sit out for a few days or more its still gummy and a drop of gas will make it real thin. No way this stuff is gonna seal this fitting that has gasoline under pressure against it.

Does anyone have another product they recommend for gas line sealant?

[Willshook]

The stuff separates such that you have to stir or knead the tube before using.

It never really "sets" completely. I don't know of anything else that's fuel safe, and everyone I know - car and aircraft - uses it.

Maybe take a hard look at the fitting and sensor to see if it's got a hairline crack? What kind of fuel pressure are we talking about?

[KyFarm]

Originally Posted by Willshook

The stuff separates such that you have to stir or knead the tube before using.

It never really "sets" completely. I don't know of anything else that's fuel safe, and everyone I know - car and aircraft - uses it.

Maybe take a hard look at the fitting and sensor to see if it's got a hairline crack? What kind of fuel pressure are we talking about?

Thanks for that, good to know that it isn't supposed to completely "set". I definitely did stir the product before using it, stirred it a bunch, doesn't look separated or bad at all.

Only running 40PSI +/-

really starting to think there is an imperfection in the threads somewhere, although I can't see or feel it.

[Getter-Done]

I have used this with great success on my Tractor fuel system.

Here is a Link below if you are interested.

Link: https://www.homedepot.com/p/GASOILA-...SS04/300281345


They even make thread tape which I have not tried.

Link: https://www.oreillyauto.com/detail/c...ufacturer=true

[KyFarm]

Originally Posted by Getter-Done

I have used this with great success on my Tractor fuel system.

Here is a Link below if you are interested.

Link: https://www.homedepot.com/p/GASOILA-...SS04/300281345


They even make thread tape which I have not tried.

Link: https://www.oreillyauto.com/detail/c...ufacturer=true

thank you, I have this question on another forum and this is the second recommendation for that product. I'm gonna try and pick some up today before I order a new sensor.