69clone
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AN fittings leak
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I love Google (except when it is politically skewed).
http://www.vsetrack.com/track_reports/2010/an_fittings/an_seals.htm
http://gsasupply.stores.yahoo.net/gaethse.html
http://www.vsetrack.com/track_reports/2010/an_fittings/an_seals.htm
http://gsasupply.stores.yahoo.net/gaethse.html
Mike67
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Did you oil the threads????
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Looks like your fittings have bottomed out. Not enough hose extending thru fittings.
If the seat does not align with ease before tightening the nut you are asking the nut to do something it was not designed to do.
Look at the seat for even contact marking.
Look at the seat for even contact marking.
CudaChick1968
Leanna ~ The Mistress of Metal
Wrap the braided hose ends with electrical tape before installing the fittings.
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Sandbug has some good info. Gasoila is a good product. A small amount of lube on the threads is a good idea especially with aluminum fittings.
Agree--When making up --AN fittings to hoses-- I use Parker o Ring lube.
A touch of it on the threads and seat is good assurance.
67Charger
Well-Known Member
I have dealt extensively with this in the Aerospace industry. This is one area where German torque specs do NOT apply ("Gutenticht"). The MOST common failure we see is cracks in the seat of the female fitting, and almost always due to OVERtorquing. There are 2 different torque values: wet and dry. If you torque to the dry value with a wet fitting, you run a very high probability of cracking the seat. If you overtourque it wet or dry, again, same problem. Look up the manufacturers specs and use them to a tee. This is critical, regardless of brand.
In the mean time, pull the hoses and use a good light and magnifying glass to examine the female fitting mating surface.
In the mean time, pull the hoses and use a good light and magnifying glass to examine the female fitting mating surface.
69clone
Well-Known Member
Thanks guys I'll take them apart and give them all a good look. Not sure what I did differently but I'm not getting any kind of leak out of the mechanical fuel pump it's only right there at the regulator. Mainly on the output side... I'll give them a thorough look.
When your talking about wet torquing do you mean using a lube? I've gotten gas all over then undoing them and reconnecting to no avail..
When your talking about wet torquing do you mean using a lube? I've gotten gas all over then undoing them and reconnecting to no avail..
67Charger
Well-Known Member
Wet = with lube. Gas is very "dry" so you can still safely use the dry values. As a side note, Loctite is not considered a lube and dry torqes are still applicable
Yatzee
Well-Known Member
I have always used push lock type fittings on my fuel lines. No furells, no fancy wrenches and no fancy colors - it's all BS and "ify". If you want industrial performance use Aeroquip or generic JIC fittings. They have to match the fuel line witch is "way hell" cheaper than Earls (or anybody else). My two vehicles pump out 55 psi to an EFI unit and I have never had so much as a drip. The matching lines are braided internally, have as many as four plies plus an abrasive resistent outer jacket. Internally, the center core is rated for various fuels (deisel, all types of gasoline like ethonl and oil so chose wisley). Unfortunately we are programmed to believe colorful AN fittings are more reliable than generic JIC and that's just not true. Crimped or pushloc fittings are rated from 100 to two thousand pounds of pressure and the lines to match are also in these ranges for both fuels or hydralics. Fittings are generally only two pieces but come in a wide range of formed offsets and lengths of extension. I personally can not be bothered with braiding, tricky attachments, lubing threads or the cost of A/N. For half the price I'll go JIC and matching pushloc hose with the result being half the connections to leak later. Each to his own.
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If your fittings are leaking, then put a conical washer on them. If a conical don't cure your issue, then replace the fitting. I've never used anything on AN fittings to help seal except a conical washer, but only had to use them a few times. AN fittings are made so no need to put anything on the matting surface. Just my experience from working on military and civilian airplanes
moper
Well-Known Member
Some thoughts:
As a rule I always use the same brand for all the fittings and hose material.
QC on the cheaper stuff is not as high.
The cut has to be clean where the hose is cut and the fitting installed to make sure it seats fully.
I always use oil and as was said - it takes very little torque to seal when the sealing surfaces are so comparatively large.
You really should have a bracket to support the regulator and the hose. Over time vibration and gravity may crack the fitting.
As a rule I always use the same brand for all the fittings and hose material.
QC on the cheaper stuff is not as high.
The cut has to be clean where the hose is cut and the fitting installed to make sure it seats fully.
I always use oil and as was said - it takes very little torque to seal when the sealing surfaces are so comparatively large.
You really should have a bracket to support the regulator and the hose. Over time vibration and gravity may crack the fitting.
69clone
Well-Known Member
I took the advice to lube the fittings and that seemed to work. Took a couple tries and I showered all the connections in lube to try and remove anything trapped between the threads. They are no longer leaking from the AN connections but the npt ends that go into the regulator they are leaking. from my understanding I could put a sealant rated for fuel on them? The NPT ends spun on with ease Til about half way then I wrenched them a few more turns.
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