Steve Schroeder Posted January 9, 2014 Report Share Posted January 9, 2014 I have been experiencing a few drops of coolant leaking after cool down on recent flights. I removed the cowling and noticed it was coming from under the number one cylinder. There was a few drops on the radiator hose so I tightened the worm hoes clamps on the radiator hose but I think I also saw a little coolant around the bottom coolant elbow where the tube meets the flange on the number one cylinder. I was wondering if coolant elbow leaks are common and if there is an easy fix. It looks like the elbow and flange would have to be removed from the engine so you could reseal the elbow into the flange....It looks like the elbow screws into the flange. Any comments, Thanks Steve. Link to comment Share on other sites More sharing options...
Anticept Posted January 9, 2014 Report Share Posted January 9, 2014 I had one too. We just took it out and put a little loctite on it. I think we put blue on it. Link to comment Share on other sites More sharing options...
FastEddieB Posted January 9, 2014 Report Share Posted January 9, 2014 I had that issue: The Rotax mechanic said to use a lot of caution and some heat in loosening the joint. He said it was very easy to strip out the threads on the elbow. I think this was the stuff he used: Link to comment Share on other sites More sharing options...
Jacques Posted January 9, 2014 Report Share Posted January 9, 2014 good info here go to Rotax-owner for full video Link to comment Share on other sites More sharing options...
mocfly Posted January 9, 2014 Report Share Posted January 9, 2014 Was watching a guy across from my hangar fool around with his Rotax 912ULS on a kite. He was having coolant leaks (21 hours on engine). He says in cold weather the heating and cooling cause the fittings to expand and contract more and coolant gets out. The fix he says is to tighten the fittings a little when you see a leak. With the hose on or off? Link to comment Share on other sites More sharing options...
Roger Lee Posted January 9, 2014 Report Share Posted January 9, 2014 The 90 degree elbows can ooze coolant. The top leak is more common. The proper Loctite is either 243 median blue or 648 green sleeve retainer. I prefer 648 and have never had a re-leak. The factory uses the blue and others that I have seen use blue may have another leak down the road. Before you remove the fitting take a magic marker and mark the elbow and fitting position so you get it lined back up where you want it. After you drain a little coolant and remove the hose on the fitting you must use heat to loosen it I use a little butane torch. Easier to just put the base in a vise because it does get hot because it may take a lot of heat. Clean the threads with lacquer thinner and apply the Loctite to both set of threads. Wipe off any excess after you screw it in and allow this to cure over night before putting any coolant back in. Piece of cake! Link to comment Share on other sites More sharing options...
Jim Posted January 9, 2014 Report Share Posted January 9, 2014 I think this is the first winter I've not had some minor coolant leak while the aircraft sits in the hanger. I've never had to do much more than tighten up fittings. Link to comment Share on other sites More sharing options...
Steve Schroeder Posted January 9, 2014 Author Report Share Posted January 9, 2014 Thanks to all for your responses...I really appreciate it. I have a couple of questions. Is there a drain on the coolant system I should use before I crack the bottom elbow fitting or should I just remove the fitting and stick a bucket under it. Also when I refill with coolant is there anything special I need to do to get the air out of the system or do I just fill it like usual through the top cap? Link to comment Share on other sites More sharing options...
Flying Bozo Posted January 9, 2014 Report Share Posted January 9, 2014 Steve, you can go to your friendly ACE hardware and get a length (about 3 feet) of small vinyl tubing. Put it in the spider and and push it down one of the legs of the spider and you can siphon off enough to get the coolant level below the fitting you are going to replace. I have done this twice now and it is easy. Then just replace the coolant that you siphoned off. Larry Link to comment Share on other sites More sharing options...
Tom Baker Posted January 9, 2014 Report Share Posted January 9, 2014 Thanks to all for your responses...I really appreciate it. I have a couple of questions. Is there a drain on the coolant system I should use before I crack the bottom elbow fitting or should I just remove the fitting and stick a bucket under it. Also when I refill with coolant is there anything special I need to do to get the air out of the system or do I just fill it like usual through the top cap? I don't know about the Piper Sport, but there is a screw on the bottom of the water pump that can be removed to drain the coolant. On the CT this screw is hard to get to, so we just pull the hose off the bottom of the radiator. If you are going to add new coolant when you are done make sure it is the same as what is already in the engine, otherwise drain all and install new. If you have Evans and are switching I would flush as well. Link to comment Share on other sites More sharing options...
Roger Lee Posted January 10, 2014 Report Share Posted January 10, 2014 I usually just pull the bottom hose off the radiator off and let it drain into a clean tub to be re-used. The I remove the offending elbow hose, remove the flange with the elbow. Put the flange in a vise, heat the flange with a small propane torch until the elbow screws out with EASE. Brush both sets of threads with a soft wire brush. Clean then with lacquer thinner and apply the Loctite 648 on both sets of threads. Screw the elbow back in place to where my alignment mark is and let it sit overnight. If I'm flushing all coolant to replace it I leave the hose off the bottom radiator and blow hard down through the fill tank on top 4-5 timers real hard. Then I sit down before I pass out. You can use a air hose and cover the tank with a rag to prevent air escape and use the hose to blow out all the coolant. This method of blowing down through the tank removes almost all coolant except for 2-3 ounces from the entire system. the bigger wind bag you are the easier it is to blow all the coolant out. Link to comment Share on other sites More sharing options...
Tom Baker Posted January 10, 2014 Report Share Posted January 10, 2014 The OP is working on a Piper Sport, so what works for the CT might not be best for him. Link to comment Share on other sites More sharing options...
Roger Lee Posted January 10, 2014 Report Share Posted January 10, 2014 I've done some Pipers. It should work. Link to comment Share on other sites More sharing options...
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