So my Mallory 4309 regulator is leaking after plumbing and setting it up to the carb (used AN fittings/cap's to set the pressure). However after a few mins or so the regulator started to leak at the two plugs I had put in it.

Previous owner had an LSx based motor in it, do these things have a max PSI rating?? Thinking the higher pressure pump compared to a TPI might cause it? Anyone ever run into these things leaking. The rest of the inlet/return fittings seemed fine. I'm open to suggestions!

 

What diameter is your return line? Too small of a return line will cause back pressure which can lead to leaks. Mine has never leaked on me. I used regular NPT pipe fittings/plugs on mine with a bit of sealant. The sealant is called Rectorseal, its in the plumbing dept at Home Depot and used for natural gas lines.

 

Thanks for the tip with the rectorseal, picked up some tonight along with some new plugs. Going to let it set for the night and see what happens tomorrow.

 

Remove fittings, clean threads (fittings and 4309 housing) of aluminum debris and reinstall.
Just went through this on my leaking like a sieve 4309.
I like to use a light coat of thread sealer to prevent galling and aid sealing.

 

I had the same problem with mine. i tried everything. Ended up using JB weld on the threads. No leaks since.

 

Teflon taped fixed my issues.

 

I would skip the tape and only use it if that's all you have at the moment.
little shreds of tape can seperate when you first install and tighten the fitting and go straight into your carb and clog the filter at best.

 

I was going to use Teflon tape when I installed my regulator as I usually have a couple rolls on hand. Then I read somewhere online that it doesn't hold up well to gas. That's when I found the Rectorseal. It's messy, but hasn't let me down yet.