# Fuel Tank Oops Fittings **URL:** \ **Category:** Everything Else\ **Created:** [March 28, 2026, 8:08pm UTC](https://sonexpilots.org/t/fuel-tank-oops-fittings/5531 "2026-03-28T20:08:16Z")\ **Posts on this page:** 15\ **Page:** 2
**Author:** ![13brv3](https://sonexpilots.org/user_avatar/sonexpilots.org/13brv3/32/695_2.png) [@13brv3](https://sonexpilots.org/u/13brv3)\ **Post date:** [March 31, 2026, 4:25pm UTC](https://sonexpilots.org/t/fuel-tank-oops-fittings/5531/21 "2026-03-31T16:25:15Z")
If someone with better CAD skills than I have could draw these up, I wonder what it would cost to get a batch made by one of those online machine shops? Does anyone know if they were making these in-house or using an outside supplier? ---
**Author:** ![13brv3](https://sonexpilots.org/user_avatar/sonexpilots.org/13brv3/32/695_2.png) [@13brv3](https://sonexpilots.org/u/13brv3)\ **Post date:** [March 31, 2026, 5:19pm UTC](https://sonexpilots.org/t/fuel-tank-oops-fittings/5531/22 "2026-03-31T17:19:24Z")
I’ve found a few bulkhead connectors that would work, and some have already been mentioned, but all the fittings I found start at 3/8" NPT for the internal threads. That’s probably bigger than we’d like for some connections, but possibly useable. They’re also typically expensive in the $80-90 range. The best thing I can find that would be fairly easy to modify would be the straight through bulkhead connections like these: > **[AN832 Union Flared Tube Bulkhead And Universal | Aircraft Spruce ®](https://www.aircraftspruce.com/catalog/hapages/an832.php)** > > AN832 Union Flared Tube Bulkhead And Universal AN832 UNION, FLARED TUBE, BULKHEAD AND UNIVERSAL > **[AN837 Elbow Flared Tube Bulkhead And Universal 450 | Aircraft Spruce ®](https://www.aircraftspruce.com/catalog/hapages/an837.php)** > > AN837 Elbow Flared Tube Bulkhead And Universal 450 AN837 ELBOW FLARED TUBE, BULKHEAD AND UNIVERSAL 45° > **[AN833 Elbow Flared Tube Bulkhead And Universal 90: | Aircraft Spruce ®](https://www.aircraftspruce.com/catalog/hapages/an833.php)** > > AN833 Elbow Flared Tube Bulkhead And Universal 90: AN833 ELBOW, FLARED TUBE BULKHEAD AND UNIVERSAL, 90º Those come in smaller sizes, but might be a bit long on the outside. Spare nuts could be cut with o-ring grooves fairly easily on a lathe. Flats could be milled on part of the bulkhead thread. I will miss those oops fitting if they don’t become available. I actually tried to get Top Rudder to use those for their tanks on the Ruckus. Rusty ---
**Author:** ![Karmarepair](https://sonexpilots.org/letter_avatar_proxy/v4/letter/k/2acd7d/32.png) [@Karmarepair](https://sonexpilots.org/u/Karmarepair)\ **Post date:** [April 2, 2026, 2:32am UTC](https://sonexpilots.org/t/fuel-tank-oops-fittings/5531/23 "2026-04-02T02:32:40Z")
US Plastics, Nylon, with Viton or Buna-N gaskets = good. Polypropylene, EPDM gaskets = BAD. ---
**Author:** ![WesRagle](https://sonexpilots.org/user_avatar/sonexpilots.org/wesragle/32/1450_2.png) [@WesRagle](https://sonexpilots.org/u/WesRagle)\ **Post date:** [April 3, 2026, 12:34am UTC](https://sonexpilots.org/t/fuel-tank-oops-fittings/5531/24 "2026-04-03T00:34:17Z")
This is, I think, the most suitable substitute for the “SNX-G01-30, 3/8 NPT Oops Fitting Qty. 1 Install in 1" Diameter Hole” fitting I have found. The price will water your eyes, but fit and function look right. [Banjo 3/8 in. 316 SS Bulkhead EPDM Fitting - John M. Ellsworth Company](https://www.jmesales.com/3-8-banjo-316-ss-bulkhead-fitting-3-8-1/?msclkid=c1f77f73d03317da45b216be2a54f13e&utm_source=bing&utm_medium=cpc&utm_campaign=Shopping%20-%20Banjo%20-%20All%20Products&utm_term=4580359297628289&utm_content=All%20Products). According to Karmarepair, the washer is wrong. > [@Karmarepair](#): > > US Plastics, Nylon, with Viton or Buna-N gaskets = good. Polypropylene, EPDM gaskets = BAD. There are any number of substitute washers available from McMasters. Wes ---
**Author:** ![WesRagle](https://sonexpilots.org/user_avatar/sonexpilots.org/wesragle/32/1450_2.png) [@WesRagle](https://sonexpilots.org/u/WesRagle)\ **Post date:** [April 3, 2026, 10:20pm UTC](https://sonexpilots.org/t/fuel-tank-oops-fittings/5531/25 "2026-04-03T22:20:50Z")
Perhaps another, less pricy, option for NPT 3/8 fitting. It **would** require different washers. ![image](https://sonexpilots.org/uploads/default/original/2X/0/0ac6ca31bd209cae2ca9a37acceb790cebcf23e8.jpeg) [Bulkhead Fitting Tank Adapter 3/8" Female 1/2" Male Brass Water Tank Connector](https://www.walmart.com/ip/Raindrops-2pcs-Bulkhead-Fitting-Tank-Adapter-3-8-Female-1-2-Male-Brass-Water-Tank-Connector/15417255292?wmlspartner=imp_4905090&clickid=x8V14O2-MxyZTNVRyk33BTxhUku1BwQYQQcq0k0&irgwc=1&afsrc=1&sourceid=imp_x8V14O2-MxyZTNVRyk33BTxhUku1BwQYQQcq0k0&veh=aff&affiliates_ad_id=565706&campaign_id=9383&sharedid=01KBZ4ZFVXE89VT1BN2ZDD0WWN). Wes ---
**Author:** ![Kevin\_Conklin](https://sonexpilots.org/user_avatar/sonexpilots.org/kevin_conklin/32/1720_2.png) [@Kevin\_Conklin](https://sonexpilots.org/u/Kevin_Conklin)\ **Post date:** [April 5, 2026, 2:26pm UTC](https://sonexpilots.org/t/fuel-tank-oops-fittings/5531/26 "2026-04-05T14:26:14Z")
For those who are not part of the Sonex Builders/Pilots Facebook group, A long time supplier of machined parts to Sonex has stated that although they are not the current supplier of the oops fittings, he can ramp up easily if necessary. ---
**Author:** ![Kevin\_Conklin](https://sonexpilots.org/user_avatar/sonexpilots.org/kevin_conklin/32/1720_2.png) [@Kevin\_Conklin](https://sonexpilots.org/u/Kevin_Conklin)\ **Post date:** [May 6, 2026, 5:37pm UTC](https://sonexpilots.org/t/fuel-tank-oops-fittings/5531/27 "2026-05-06T17:37:05Z")
Can someone verify the quantity and size of each oops fitting needed? ---
**Author:** ![ampzapper](https://sonexpilots.org/user_avatar/sonexpilots.org/ampzapper/32/3313_2.png) [@ampzapper](https://sonexpilots.org/u/ampzapper)\ **Post date:** [May 6, 2026, 6:05pm UTC](https://sonexpilots.org/t/fuel-tank-oops-fittings/5531/28 "2026-05-06T18:05:03Z")
If your tank has the molded in inserts it’s qty 1 of 3/8" and qty 4 of 1/8" used as follows: Qty 1: 3/8" main tank outlet Qty 1: 1/8" for fuel level sensor Qty 1: 1/8" for fuel vent Qty 2: 1/8" for tube based fuel level (one at bottom and one at top) I know some people don’t replace all the 1/8" ones and some do. Also if you don’t have the molded inserts in the tank you wouldn’t need all of them. And if you need a fuel return for your system a 1/4" may be required. ---
**Author:** ![Bryan\_Cotton](https://sonexpilots.org/user_avatar/sonexpilots.org/bryan_cotton/32/760_2.png) [@Bryan\_Cotton](https://sonexpilots.org/u/Bryan_Cotton)\ **Post date:** [May 6, 2026, 6:52pm UTC](https://sonexpilots.org/t/fuel-tank-oops-fittings/5531/29 "2026-05-06T18:52:01Z")
I put oops fittings in the sump and just plugged the top fitting, figuring it would not have much fuel pressure if any. ---
**Author:** ![RonJ](https://sonexpilots.org/user_avatar/sonexpilots.org/ronj/32/3689_2.png) [@RonJ](https://sonexpilots.org/u/RonJ)\ **Post date:** [October 18, 2026, 12:47am UTC](https://sonexpilots.org/t/fuel-tank-oops-fittings/5531/30 "2026-10-18T00:47:27Z")
Hello, I am new to this website and not exactly sure how to respond. I am presently flying a sonic‘s tail number in 2067 whiskey. I am an A&P mechanic, and have a situation with my fuel tank leak at the shut off point and could use one of the fittings? I just wondered if you had any left for sale? Thank you for your time. Ron J ---
**Author:** ![Bryan\_Cotton](https://sonexpilots.org/user_avatar/sonexpilots.org/bryan_cotton/32/760_2.png) [@Bryan\_Cotton](https://sonexpilots.org/u/Bryan_Cotton)\ **Post date:** [October 18, 2026, 1:33am UTC](https://sonexpilots.org/t/fuel-tank-oops-fittings/5531/31 "2026-10-18T01:33:50Z")
Ron, You can buy them from Sonex again. > **[Sonex Web Store - Oops Fitting: 3/8 NPT ...](https://www.sonexaircraft.com/eshop/cart.php?target=product&product_id=20284&substring=Oops)** > > \Oops Fitting: 3/8 NPT for Sonex Fuel Tank\ \Did you over-tighten the molded-in NPT fittings in your Sonex Fuel Tank, or neglect to clean the threads before installing your fittings? Instead of replacing your entire fuel tank, you may... Note they have 3 different sizes, I just linked the big one. ---
**Author:** ![Kevin\_Conklin](https://sonexpilots.org/user_avatar/sonexpilots.org/kevin_conklin/32/1720_2.png) [@Kevin\_Conklin](https://sonexpilots.org/u/Kevin_Conklin)\ **Post date:** [October 18, 2026, 1:36am UTC](https://sonexpilots.org/t/fuel-tank-oops-fittings/5531/32 "2026-10-18T01:36:37Z")
Confirmed. After Sonex restarted, I ordered the fittings from the web store and received them - no problems. ---
**Author:** ![RonJ](https://sonexpilots.org/user_avatar/sonexpilots.org/ronj/32/3689_2.png) [@RonJ](https://sonexpilots.org/u/RonJ)\ **Post date:** [October 18, 2026, 3:15am UTC](https://sonexpilots.org/t/fuel-tank-oops-fittings/5531/33 "2026-10-18T03:15:38Z")
Hello Brian, thank you for your help with that issue. I will check with Sonex for those parts, thanks again Ron J ---
**Author:** ![Bryan\_Cotton](https://sonexpilots.org/user_avatar/sonexpilots.org/bryan_cotton/32/760_2.png) [@Bryan\_Cotton](https://sonexpilots.org/u/Bryan_Cotton)\ **Post date:** [October 18, 2026, 5:11pm UTC](https://sonexpilots.org/t/fuel-tank-oops-fittings/5531/34 "2026-10-18T17:11:06Z")
I don’t know if @David-A 's tool for the oops fittings is still around, but it helps a lot. ---
**Author:** ![David-A](https://sonexpilots.org/letter_avatar_proxy/v4/letter/d/3ab097/32.png) [@David-A](https://sonexpilots.org/u/David-A)\ **Post date:** [October 18, 2026, 11:45pm UTC](https://sonexpilots.org/t/fuel-tank-oops-fittings/5531/35 "2026-10-18T23:45:53Z")
Yes, I and the Oops fitting tools are still around. Plane and spare engine are long but the tools remain. Send me a message with the address you need them sent to - in the US - and i will send them out via priority mail, just reimburse me for the shipping when you return them. David A. [Previous page](https://sonexpilots.org/t/fuel-tank-oops-fittings/5531.md?page=1)