The International Cessna^® 170 Association

Hello Again,

Since I am now in the "looking for a sump business", I have been reading the Continental Engine Overhaul Manual (available online at the TCM website). I also searched our forum for sump repairs. BTW - I have counted holes and appear to have the 5 hole sump.

1. Sump material - all the posts I have seen seem to indicate the sump is magnesium. However, the TCM Manual describes it as an aluminum casting. Does anyone know what it is? I suppose it does not really matter. If I repair my existing sump any shop that I use will know. I just thought I would ask.

2. I searched the forum for sump repair. I came up an old post that indicated dissatisfaction with a shop named Drake repair and another shop that escapes me just now. What is the current consensus as to the best place to get one of these repaired?

Regards,
Pete P.

Pete, I read the same thing you're read from the manual!
I'd be curious to know the specific magnesium alloys used, guess we would have to ask Continental for that info. I always thought both components were made out of the same material or at least they appeared to me to be the same when I took my 0-300B apart. My sump had the same issue that I believe you have. I believe I've posted this before but again, when first looking at the inside of my sump it appeared to be in good condition. But as I cleaned away the oil goop inside lower surface with a cotton cloth, the sump internal surface material simply turned into the consistency of sand. I literally with no effort, wiped away the inside surface material around the drain plug and the built up area of the carb stud attachment bosses.
So sorry I'm not really helping you here with your question because it's just speculation on my part as to what the material is.
I'd just like to comment that it would also be speculative to suggest you sump would have a catastrophic failure. I would think your oil leak would just increase in its rate as the sealant repair lost its grip. But having said that as the failure mode going forward is somewhat unknown, I would trend towards the conservative approach in this instance and repair asap.

Arash, whilst I was poking away at my IPad, you made a new post . I recently had some 3D Boroscope training at work and I think with our 4mm or 6 mm scopes it would be difficult to get in there, that being the area ahead of the carb. That area is affected ( my belief) because of the slope of the sump would allow water to accumulate at the low point between the forward plug's aft side and the forward base of the carb attach boss. Even if you were to do some disassembly to gain access, I'm suggesting a visual may not be sufficient to assess whether there's an issue.

There is a firm located in Kelowna, BC , which we visited at the 2006 C170 convention, that has a process for repairing our sumps. They line the entire sump with a material that prevents future corrosion. I don't remember the details, but it seems they won't preform the process if the sump has had prior attempts at repair (inside) and I am not sure if they do so if the sump is already leaking. Some of our members will probably recall more details and have the name of the firm available.

Hello everyone,

I asked an old IA in my neighborhood whether he had a useable sump and as to repair options. He didn't have a sump. He thought he had one but apparently sold it earlier - said he is either getting old-timers disease or has too much stuff around the hanger. Here is what he told me regarding repair options. BTW - this guy is an old-timer (approx 70 yr-old) in our neighborhood. For last couple decades has been doing field overhauls of engines. Has an excellent reputation in our airpark, FA40. Doesn't do annuals anymore and is semi-retired. I have always respected that he knows GA aircraft engines. So here is what he told me after he researched the matter:

1. Remove sump and send it to some place in Utah that was recommended to him. He has not used the Utah shop before but his network of repair contacts says that they are reputable. Cost about $500 - IF the sump can be repaired.

2. Remove sump and send to Divco for repair. (Note - in earlier post I said a forum search listed dissatisfaction with Divco repair. I was incorrect and edited that post. Shop's name was Drake). The IA uses Divco and says they are reputable. I asked him whether they offer a warranty on their repair; he didn't know but will ask. Cost about $500 - $800.

3. Try to find a serviceable old sump. However, from what I am reading about these old sumps I would be suspicious of re-using one without hot de-greasing and some sort of NDE test for porosity. As is apparent, these are 50+ yr-old parts. Since my sump is still on the plane, I don't know if mine is even repairable. One of our members has kindly offered to sell me a spare he has. I will take him up on that. Hopefully, with two candidates, one will be repairable.

The IA also recommends if we remove sump (which he does recommend), we should get a new gasket and take accessory case off instead of fussing about and trying to re-use the old gasket. I agree with him on this. I don't want to fix one leak and cause another - but more $$$.

Looks as though this is going to be an expensive repair. Which is why the past field overhauler cut corners and tried the epoxy patch that didn't hold up. But at this point I want it done right. Just one of those aspects of owning a vintage airplane I suppose. Sigh...

Regards,
Pete

The other option, the repair shop in Kelowna, BC has epoxy repaired many sumps with success and is an approved process. When I talked to them in 2006, they told me some they had repaired had gone thru a couple of TBOs and were still servicable without further repair.

They WILL NOT touch a sump that has had any type of weld repair due to potentail cracking although I would think your bootleg epoxy repair would not be included in that policy. You would have to check on that. You would also have to check on if they will repair a sump with an actual hole as opposed to porosity. But those things could be handled with one phone call.

One thing about their epoxy repair is that it covers the entire sump and eliminates any further corrosion problems due to trapped water or other contaminates because the repair completely coats the interior of the sump.

Mine is going on 8 years since repair and there is no evidence of failure although to be fair, chunks of epoxy would have to be falling out for me to be able to detect it. There are no chunks so far.

There are many of these sumps out there but no more are being made so repairing the ones we have left makes a lot of sense to me as opposed to junking and replacing with servicable parts.

The aero engine facility in Kelowna is:

Okanagan Aero Engines, LTD.
5550 Aerospace Dr, Kelowna, BC V1V 1S1, Canada
+1 250-765-9718

Hello everyone,

The saga continues... My sump is at DIVCO for repair but it is so badly cracked that they rejected it. So I am back to looking for an alternative.


So, what does anyone know about this shop in B.C. or about this repair process? Is it a valid repair? Can you legally use it on a US certificated aircraft? Is there any track record with this repair.

Okanagan Aero Engines, LTD.
5550 Aerospace Dr, Kelowna, BC V1V 1S1, Canada
+1 250-765-9718

The reason I suggested you contact them is so you can satisfy yourself of their process.
Yes, it's a good repair , in my opinion. (Did you notice that Richard's sump was repaired by them and he endorsed their repair? and that his engine is flying on his U.S. registered 170?)
But....if your sump is c r a c k e d ...I doubt they can help you except to sell you a serviceable sump, perhaps.

Those look to be mold lines not repairs.

Aryana wrote:Got it. This could be a good candidate part for ptporebski to get up and running relatively cheap.

I'm thinking if I was he, I wouldn't blink. I'm only hoping mine is at least in this shape.

I'd also send it to Okanagan for their treatment before it corrodes all the way through.

Glad to hear you found the leak. I'm still wondering why the the leaking fluid was blue/green.

I do my annual in Dec as winter weather can limit flying. At that time I change my oil and clean the screen regardless of the hours. Often I change my oil mid summer due time on it which means at annual the oil often only has 10-20 hours on it. The color of the oil around that time, I'll describe as being Aqua marine green (secret speed, oil).
So it all makes sense to me

c170b53 wrote:I...The color of the oil around that time, I'll describe as being Aqua marine green (secret speed, oil).
So it all makes sense to me

That explains why it's SLOW to indicate pressure on the gauge!

Hello Everyone,

It's been awhile since this post started. Here is the end of the story. So, I took Aryana's and others advice and purchased a used 5 hole sump after Divco said they could not repair mine. But I did have them return my original leaking sump.

As I related at the beginning of this thread I am a mechanical engineer and work for a large power utility that runs a fleet (130+) of power plants including several nukes. We have a NDE group that has some sophisticated tools and people with the certifications to know how to use them. We also have welding engineering and procedures for most any type of situation. Finally, we have top notch certified welders capable of any repair. My plan was to have them analyze the metal, find the recommended weld procedure, and pay one of the guys to do a repair on the side. I figured for relatively little I would have a spare 5 hole sump that I knew was properly repaired.

I took the old sump to the NDE boys and asked for an alloy analysis. Much to my (and their) surprise the primary constituent in the sump repeatedly came back as Zinc. Something like 79 - 82% zinc with other traces of Ti, Mn, etc...

We are going to do some more exotic tests as the guys have spare time. They used a field analysis gun after cleaning and etching a small section of the sump. But that tool is routinely used around the plant and we have always found it's results accurate.

I am posting this because I had confusion over whether these sumps are Al or Mg. The tribal knowledge says Mg but the old Continental documentation says Al. I certainly wasn't expecting it to be Zn. To make the story more mysterious there appears to be an old weld repair to the sump as the technician pointed out two weld beads plainly visible on the side. I will post a couple of photos of that tonite. But I thought the group might find this interesting.