Leaking Oil Sump Gasket

[dacker]

I have a '49 with the O-300A. I have recently developed a bodacious oil leak which seems to be coming from the lower sump gasket. The local A&P isn't too interested in replacing the gasket. I believe he is wary of what he may get into if we start dismantling things. It appears that at the very least we would have to partially disconnect the engine mounts and lift the engine some or just pull the engine entirely. I also believe the accessory case would have to come off as well to replace that gasket when we pull the sump. It looks like the typical senario where you have 20 hours of labor for a $50.00 part. I have about 1400 hours on the engine and cylinders are mostly in the mid 70's except for two in the mid 60's. I am thinking of possibly just going for a complete rebuild and saving on some of the labor. This is long winded, but has anyone had the similar problem and how did you fix it? I don't feel too comfy with losing a quart/hour and it is hard to look good when you have oil smeared all over the airplane!

[GAHorn]

Hi, Dave!
Are you talking about the crusty old guy at Coulter? or the one over at Easterwood?
If the engine is otherwise in good shape, you'll be throwing away about 400 hours of engine time, worth about $3000-$5000 at bluebook overhaul prices (and about 4-5 years of flying if you're average.) Changing that gasket shouldn't cost more than about $500-$700 including parts, as long as you don't lose the exhaust, hoses and mounts in the process. So you might want to consider the health of those items before you make the final decision. Have you considered doing the work yourself and paying for supervision and signoff? That may be a less expensive avenue.
(Buddy McGown said he'd run into you.)

[doug8082a]

I went through this exercise about two years ago on my '52 with an O-300A. We had to pull the engine and remove the accessory case in order to remove the sump (as you had already guessed). This turned out to be a blessing in disguise. When we removed the sump we discovered quite a bit of corrosion in the bottom of the sump. This problem is described in the Cessna 170 book from the Association (sorry, I don't have it in front if me to give you the page number) and the photos in the article were almost identical to the corrosion we found.

Sooooo, Going through the effort may be worthwhile for you if you want to keep the engine. I'm glad I did it since the corrosion was bad enough that my mechanic was able to poke a hole through what little metal remained in the bottom of the sump . I was not too far from emptying 8 qts. of oil somewhere over southern New England.

My 2 cents. Good luck!

Doug
N8082A

[dacker]

Thanks for the replies George & Doug. We are on the same page about the economics, I was guessing 400 hours would be worth about $4000. I bought the airplane to keep building time while I am going through my stay-at -home dad phase, so I have been able to fly it about 20 hours a month so far (I am nowhere near getting bored with it). I believe I will probably pull the engine entirely and at least get a peak inside before I make any final decisions. The exhausts are new and hoses shouldn't be to terribly expensive. This might be my chance to start working on that A&P certificate via the University O'Hardknocks. Now if I can just get the locals to make a move.
David
9584A

[GAHorn]

Dave, Don't forget that Ron Stegemoeller down at Brenham is a good mechanic as well, and it's only a short drive if you need to check up on it.

[n3833v]

I'm not sure how accessable the leak is, but Caterpillar engines has an epoxey kit they use for oil leaks at head gaskets and gear cover flanges at block. It might help to contain the leak. Just need to prepare with cleaner and then epoxey. When overhauling, reclean surfaces.
John - n3833v

[GreggHorrell]

I would start by going around and checking the bolts....might have loosened up a little allowing the leak. This is pretty common.
Gregg

[dacker]

Thanks for all the help! Yes, I certainly checked all the bolts on the sump first, as well as to make sure the leak wasn't coming from anywhere else (I originally thought it was from those pesky pushrod tubes). Also I just never have trusted or had much luck in using a sealer to stop a leak. I talked the A&P into supervising me, so I am going to just pull the whole darn thing off the airplane. Ordered all the books I could find on the O-300A and am going to get after it next week. In a couple of weeks I will be an expert on O-300 sumps and accessory cases or at least the leaks they can cause. I will post an update after my adventure.
Keeping a good Karma!
David
9584A

[dacker]

Just to update on the leaking sump. George, I got fed up with trying to repair my airplane at Coulter so I took your advice and called Ron at Brenham. This turned out to be a blessing in itself - not only did he take the job but I found a hangar there. Great little airport! The FBO is opening a small cafe and things seem to be run pretty professionally there. Ron runs a busy shop, but it is clean and professional looking. He was able to replace the gasket without damaging the accessory case gasket. The charges were even less than I expected (how often does that happen?). Anyhow 9584A is in the air again and not spreading oil all over the Brazos Valley. On a side note I looked a litle closer at my logs, I only have about 500 hours on the engine not 1400 like the tach says . I hope to see a lot of the other TIC170Aers at Reklaw later this month.
Thanks
David Acker
9584A

[N1478D]

David, I'll be camped behind the white with green trim A model. Looking forward to meeting you at Reklaw, what color scheme does yours have? We are planning on flying to a Tractor Pull this Saturday, landing at Temple, if you are interested

[GAHorn]

Just to update on the leaking sump. George, I got fed up with trying to repair my airplane at Coulter so I took your advice and called Ron at Brenham. This turned out to be a blessing in itself - not only did he take the job but I found a hangar there. Great little airport! The FBO is opening a small cafe and things seem to be run pretty professionally there. Ron runs a busy shop, but it is clean and professional looking. He was able to replace the gasket without damaging the accessory case gasket. The charges were even less than I expected (how often does that happen?). Anyhow 9584A is in the air again and not spreading oil all over the Brazos Valley. On a side note I looked a litle closer at my logs, I only have about 500 hours on the engine not 1400 like the tach says . I hope to see a lot of the other TIC170Aers at Reklaw later this month.
Thanks
David Acker
9584A

Glad that Ron could help you. I'm afraid I'll probably not make Reklaw this year due to my work schedule. (Damn!) But hopefully we'll get together again soon. (Don't park too close to N1478D. That "slow" virus probably doesn't infect too many A-models but it may be contagious.)

[dacker]

Joe, funny you should ask about the color. When I brought my wife to do the "spouse pre-buy" she took one look and said " It's nice but it looks like a pumpkin!" . To answer your question it is beige with brown and orange stripes. You will find me camped out with my smart and pretty little eight year old who never stops talking. I am looking forward to seeing a gaggle of 170s. I am looking for a few ideas.
David
9584A