Barry.h Posted December 6, 2021 Report Share Posted December 6, 2021 I went for a fly last weekend for some local soaring in pretty average conditions so I kept the engine idling (and used it a few times) on a 2.1 hr flight. When I landed and parked I noticed a puddle under the engine and realised I had oil all under the fuselage. The engine still burped (gurgled) when i turned the prop but there was no oil visible on the dip stick. This was only my 4th day flying since the annual inspection and oil change. Some investigation found a small triangular hole on the underside of the oil filter. Some further investigation concluded it was caused by the nut on the hose clamp on the radiator. With the cowls off the radiator hangs down but I assume when all mounted the radiator is raised up and puts the hose clamp within striking distance of the oil filter. Some rough, one-hand video here: https://photos.app.goo.gl/1qEBsKLyQCorRkih8 I have not put it all back together yet - so I don't know how close it is in normal position, but we will obviously be moving the hose clamp screw! I think I was very lucky ... it must have failed just as I was taxing back, (After a very smooth landing I might add - first real X-wind for me!) based on the size of the puddle both where I parked and where I had to wait a few minutes to get back to my hangar. I didn't lose oil pressure so I assume no further harm done. Has this been seen before? Certainly worth checking! Barry Quote Link to comment Share on other sites More sharing options...
Jim Lee Posted December 6, 2021 Report Share Posted December 6, 2021 When you have lost oil from the engine don't burp it because you can introduce air into the system and damage the engine. When air is introduced into the system, you must purge the air from the system or the engine can be damaged. You can (and should) burp the engine prior to doing the oil change to put oil into the canister before draining it. You can remove an oil filter and drain oil from the oil canister at that time, but do not burp the engine after you have drained the oil or air can be introduced. Quote Link to comment Share on other sites More sharing options...
Registered Eric Greenwell Posted December 6, 2021 Registered Report Share Posted December 6, 2021 I had the same thing happen to me after a "rubber change", where I noticed drips on the hangar floor after about 10 hours from the rubber change, drips which got worse with more flight time. Eventually, I found the leak in the filter. With the cowling off, the radiator hangs down, giving the appearance of plenty clearance for the hose clamp in the "up" position. The proper location is 180 degrees from your position. The amount of clearance varies from plane to plane, so some with the hose clamp "up" don't touch the filter, and all is well. Some/lots of oil got into the oil radiator fins. I tried to clean it out with solvent and some air pressure, but it still took many hours of engine time before the drips on the floor ended. Quote Link to comment Share on other sites More sharing options...
Doug Levy Posted December 7, 2021 Report Share Posted December 7, 2021 What kind of oil filter is that? Not that has anything to do with the puncture. I've been getting some small paint roller trays to put under the filter to catch the oil drops from the filter during oil changes. Do you fill the oil to the top of lines on the dip stick? I've been told not to fill it that far to reduce the amount of oil film that is produced from blow-by then down the tube at the top of the oil tank and then out on to the fuselage. Glad you caught the problem before any harm. Quote Link to comment Share on other sites More sharing options...
Barry.h Posted December 7, 2021 Author Report Share Posted December 7, 2021 As far as I know it is the standard Rotax filter. I get my aircraft maintained by a local Aircraft Engineer/Mechanic who I have a lot of confidence in. He is also my Gliding Federation Level 3 instructor so he flies my plane a bit too - adding to the confidence levels. So I leave all the detailed maintenance stuff to him. But I can note ... after the last oil change it was filled a bit more than before, perhaps 3/4 way up the flat. Quote Link to comment Share on other sites More sharing options...
Registered Eric Greenwell Posted December 7, 2021 Registered Report Share Posted December 7, 2021 10 hours ago, Doug Levy said: Do you fill the oil to the top of lines on the dip stick? I've been told not to fill it that far to reduce the amount of oil film that is produced from blow-by then down the tube at the top of the oil tank and then out on to the fuselage. For flying when I intend to return home, I fill it to the bottom of the flat (that's without burping), which I think is what Jim recommended; burping it after doing that puts the oil about half-way up the flat. If I'm leaving on a trip, I'll fill to the half-flat (without burping), so I don't have to add as much oil during the trip. Quote Link to comment Share on other sites More sharing options...
Doug Levy Posted December 8, 2021 Report Share Posted December 8, 2021 I've been getting Rotax oil filters from California Power Systems / Aircraft Spruce. Quote Link to comment Share on other sites More sharing options...
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