Guitarmaster Posted March 18, 2014 Report Posted March 18, 2014 Hey guys... Pulled the plane out yesterday, tried to sump the left tank and close to nothing came out. The valve opens, I can feel it, but very little comes out. Clearly there is an obstruction in the small holes in the sump. Worked fine the day before. Any ideas on how to clear it? Thanks! Sent from my iPad using Tapatalk Quote
carusoam Posted March 18, 2014 Report Posted March 18, 2014 A wrench? Realistically, the dangers of fuel fire is too high to attempt this based on internet support. But two things come to mind... 1 ) Are you seeing black specks when trying to take a sample? Typical of rust... 2 ) Are you below freezing lately? Typical of water intrusion... Best regards, -a- Quote
Guitarmaster Posted March 18, 2014 Author Report Posted March 18, 2014 Black specs.. No. Below freezing... Yes. Well below, preceded by a couple of warm days. Water (ice) was my thought as well. It is above freezing this week so I will see on Thursday. Thanks for the response! Sent from my iPad using Tapatalk Quote
Marauder Posted March 18, 2014 Report Posted March 18, 2014 Hey guys... Pulled the plane out yesterday, tried to sump the left tank and close to nothing came out. The valve opens, I can feel it, but very little comes out. Clearly there is an obstruction in the small holes in the sump. Worked fine the day before. Any ideas on how to clear it? Thanks! Sent from my iPad using Tapatalk  Oh boy! This sounds familiar and since I am only a handful of serial numbers from your plane, I might have an answer -- and hopefully I'm wrong! Have your tanks been resealed?  On the 1975 model I own, the sealant they used was not very good. In order to protect it, they put a more fuel resistant coating on top of the tank sealant. When I was going through the pre-buy back in 1991, I found a bunch of "worms" in the tank and had difficulty draining the sumps. The "worms" were the top coating peeling off and floating around in the tank. Since the sump is a low spot in the tank, many of the worms settled there, plugging up the sumps. 1 Quote
Guitarmaster Posted March 18, 2014 Author Report Posted March 18, 2014 Great Sent from my iPad using Tapatalk Quote
Marauder Posted March 18, 2014 Report Posted March 18, 2014 Great Sent from my iPad using Tapatalk Sorry... Like I said, hope I'm wrong. If you have this problem, look in the tank. The worms are red. BTW -- still want the schematics? Sent using Tapatalk Quote
N201MKTurbo Posted March 18, 2014 Report Posted March 18, 2014 Just fly that tank till it is almost dry and leave some room in the other tank. Put a 5 gallon bucket under the drain and remove the drain. Have another bucket ready in case the first one gets too full. When the first bucket is about 1/2 full switch buckets and pour the gas into the other tank. A big metal funnel (oil drum funnel) is handy for this and a helper is good too. The act of draining the fuel will most likely clear the obstruction. If not shine a flashlight into the hole and see what is blocking it and remove it with some needle nose pliers. Â Consider having a fire extinguisher handy. The only thing dangerous about this is if a fire starts there is no good way to stop the fuel flow, so start with an almost empty tank. Quote
Hank Posted March 19, 2014 Report Posted March 19, 2014 Be careful with that! Fueling should be grounded to prevent static buildup and discharge, i.e., sparks . . . . . Quote
Guitarmaster Posted March 19, 2014 Author Report Posted March 19, 2014 Thanks everyone! I am reasonably sure it is water that has settled around the sump and froze. We had some cold days, followed by 45+ followed by 9 degrees. Is this winter EVER going to end? Every time I have sumped the fuel In the warm weather I get some measure of water. It is too coincidental that this problem showed up as the temp took a drastic drop overnight. I am flying a trip for work right now, so I will find out Thursday if frozen water is the problem. Turbo... Thanks for your input! If the warm weather does not solve the problem, I will go this route. Hank... Yes, I will be extremely cautious. Marauder... Yes, I would love the schematics! I still have to find the problem. I shouldn't have to pull the gear warning horn breaker to fly at night. I know the problem is the nav light dimming relay, I just need to find it. Thank you! I looked in the tanks pretty close on the pre-buy and saw nothing floating in the fuel. This was the main thing I was looking for when I was looking at RVs as well. Also, I didn't find anything about top coating the sealant in the tanks in the the logbooks. I have to assume it has not been done. The airplane has less than 1700 hours on it. Take care! Sent from my iPad using Tapatalk Quote
Marauder Posted March 19, 2014 Report Posted March 19, 2014 Marauder... Yes, I would love the schematics! I still have to find the problem. I shouldn't have to pull the gear warning horn breaker to fly at night. :)I know the problem is the nav light dimming relay, I just need to find it. Thank you!I looked in the tanks pretty close on the pre-buy and saw nothing floating in the fuel. This was the main thing I was looking for when I was looking at RVs as well. Also, I didn't find anything about top coating the sealant in the tanks in the the logbooks. I have to assume it has not been done.The airplane has less than 1700 hours on it.Take care! Sent from my iPad using Tapatalk I will get the schematics over to you tonight. My tanks were original in 1991. I was told that the sealant was factory installed when they began seeing issues after moving the fleet to 100LL. Not sure if this is true, but I clearly had two coatings in my tanks and no log book entry. If you have original tanks, check into replacing the O rings on the caps. They can let a fair amount of water in. Quote
Piloto Posted March 19, 2014 Report Posted March 19, 2014 Be careful with slow fuel drains. You could have susbstantial amount of water in the tank even thought you did not see it on your drain cup. It caused me engine stoppage on take off.  When there is too much debris or sealant at the very bottom of the tank it will plug the drain valve mounting  nut plate drain holes. This will cause that instead of draing fuel from the valve bottom holes it will drain from the top of the valve stem. This will cause the valve not to drain the water below the stem top but the fuel above it. The top of the stem is above the tank fuel pick up screen so it will submerged in water. When this happens you will see a substantial amount of water when the valve is removed.  I found that the best soulution to avoid the problem in the future is to just replace the valve with F-391-72 (same used on Monroy tanks). Instead like the old one the -72 has the drain holes above the thread. This expose the drain holes directly into the tank instead of the holes in the bottom that are subject to be clogged by the mounting nutplate.  You will not see engine stoppage during taxing but when the plane accelerate were the water gets shifted toward the back where the fuel pick up is located.  If you suspect the above just untight the valve to drain thru the threads until clear fuel is visible.  José Quote
Guitarmaster Posted March 19, 2014 Author Report Posted March 19, 2014 Marauder.. I will definitely keep a lookout for the worms. Thanks in advance for the schematics! Jose... Thanks so much for your input! I never thought about simply loosening the sump to draw past the threads. Side note... I love these message boards and the people on them. It started for me with performance tuning my diesel truck and now with my "new" airplane. I thank each and every one of you for taking the time to share your experiences and knowledge! Matt Sent from my iPad using Tapatalk Quote
Mooneymite Posted March 19, 2014 Report Posted March 19, 2014 I've never had worms in my fuel bladders. (Sorry. I just can't resist restarting old arguments.) :-) 2 Quote
Marauder Posted March 19, 2014 Report Posted March 19, 2014 I've never had worms in my fuel bladders. (Sorry. I just can't resist restarting old arguments.) :-) Me either -- since I changed over to bladders! Sent using Tapatalk 1 Quote
jetdriven Posted March 19, 2014 Report Posted March 19, 2014 It's funny. I've had zero problems with my fuel tanks as well, except they only hold 54.7 gallons. 1 Quote
BigTex Posted March 19, 2014 Report Posted March 19, 2014 Same here... but that's a conversation for another thread! Quote
Guitarmaster Posted March 21, 2014 Author Report Posted March 21, 2014 I just thought I would let you guys know, the problem was a small amount of water that had frozen around the holes in the sump. Â Problem solved with just a little warmer weather. Â [big sigh of relief!] Â It was a surprisingly small amount of water. Â Well, live and learn. Â That was a new one on me. Â Now on to bleeding the brakes, troubleshooting the PC system and a visit to the radio shop to get the HSI working properly. Â Cheers! 2 Quote
Mooneymite Posted March 21, 2014 Report Posted March 21, 2014 I love stories with happy endings! Â Â 1 Quote
BigTex Posted March 21, 2014 Report Posted March 21, 2014 I love stories with happy endings! +1 on happy endings! Quote
carusoam Posted March 21, 2014 Report Posted March 21, 2014 Step 2: The caps will often have water sitting on them when stored outside. If they never have water on them, it's worth looking for why... Then look for rust... Possible solutions... Needs adjustment or new o rings (there are two per cap) Needs new SS fill ring (sheet metal that the cap locks in). originals rust through. SS is the way to go. 65C experience, -a- Quote
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