engine trouble

On Sun, 06 Feb 2005 02:01:14 GMT, "Mike Rapoport"
wrote:

You might check into a "wicking sealant". I know permatex makes one, but I
don't know the part number. Do it at night since it is not aircraft stuff.
It has worked for me on a variety of leaks on transmissions and transaxles.
Of course you need to remove the RTV and clean the area with brake cleaner
first.

There is a letter circulating around from TCM concerning case seam
leaks.

The gist of the process is remove any leaking case bolts in the area,
clean thoroughly with MEK (brake cleaner would work), and apply
cyanoacrylate adhesive.

That's right, super glue. You hook a shop vac up to the breather, turn
it on, clean things up and let dry thoroughly. Turn the vac back on,
apply the glue to the seam and on the inside of the bolt holes.

Let it dry, put it all back together, torque the bolts and fly the
crap out of it.

Had really good luck using the extremely thin hobby stuff, then
painting the thicker stuff down the seam (sparingly) after the thin
stuff is dry.

Is an "approved" repair for TCM products, and I have used it with good
results.

You hit the nail on the head, it is a "wicking" leak in most cases,
and a wicking sealant will stop it...

Regards;

TC

wrote in message
...
On Sun, 06 Feb 2005 02:01:14 GMT, "Mike Rapoport"
wrote:

You might check into a "wicking sealant". I know permatex makes one, but
I
don't know the part number. Do it at night since it is not aircraft
stuff.
It has worked for me on a variety of leaks on transmissions and
transaxles.
Of course you need to remove the RTV and clean the area with brake
cleaner
first.

There is a letter circulating around from TCM concerning case seam
leaks.

The gist of the process is remove any leaking case bolts in the area,
clean thoroughly with MEK (brake cleaner would work), and apply
cyanoacrylate adhesive.

That's right, super glue. You hook a shop vac up to the breather, turn
it on, clean things up and let dry thoroughly. Turn the vac back on,
apply the glue to the seam and on the inside of the bolt holes.

Let it dry, put it all back together, torque the bolts and fly the
crap out of it.

Had really good luck using the extremely thin hobby stuff, then
painting the thicker stuff down the seam (sparingly) after the thin
stuff is dry.

Is an "approved" repair for TCM products, and I have used it with good
results.

You hit the nail on the head, it is a "wicking" leak in most cases,
and a wicking sealant will stop it...

Regards;

TC

TC,

If you could forward me a copy of that letter I would appreciate it. Nobody
here has heard of it.

Thanks,

Allen

On Tue, 08 Feb 2005 22:24:37 GMT, "Allen"
wrote:

snip

TC,

If you could forward me a copy of that letter I would appreciate it. Nobody
here has heard of it.

Thanks,

Allen

The last copy I obtained is somewhere at my previous employer's shop.
I got it by calling TCM tech support and asking them for it
specifically.

It is an old advisory letter addressing crankcase backbone leaks, does
not have a SB # or anything like that.

TC

wrote:
: The gist of the process is remove any leaking case bolts in the area,
: clean thoroughly with MEK (brake cleaner would work), and apply
: cyanoacrylate adhesive.

: That's right, super glue. You hook a shop vac up to the breather, turn
: it on, clean things up and let dry thoroughly. Turn the vac back on,
: apply the glue to the seam and on the inside of the bolt holes.

: Let it dry, put it all back together, torque the bolts and fly the
: crap out of it.

: Had really good luck using the extremely thin hobby stuff, then
: painting the thicker stuff down the seam (sparingly) after the thin
: stuff is dry.

: Is an "approved" repair for TCM products, and I have used it with good
: results.

: You hit the nail on the head, it is a "wicking" leak in most cases,
: and a wicking sealant will stop it...

Holy crap... Superglue on an airplane? I was concerned that the minor seam
leak on my Lycoming O-360 was indicative of case fretting. Now I see that it's a
common problem and nothing to worry about. I guess I'll doublecheck the torque specs
on the case bolts and then get some RTV. It's only enough to cause a sheen on the
case after a long flight, so it's not enough to measure. Only disturbing thing is
what little gets blown on the side of the case goes through the jugs and seems to hit
the exact same spot on the muffler. There's a bit of a "burn oil" stain on it.

Still... I consider *any* oil on a hot muffler unacceptable, even if it's
1/100 of a drop per second.

Overhaul on an oil leak? Sh*t... nobody'd be flying if these drippy, scummy,
blowby-ed, lead-fouled creatures if needed an overhaul whenever they made a mess...

-Cory

************************************************** ***********************
* Cory Papenfuss *
* Electrical Engineering candidate Ph.D. graduate student *
* Virginia Polytechnic Institute and State University *
************************************************** ***********************

On Wed, 9 Feb 2005 18:15:45 +0000 (UTC),
wrote:

snip

Holy crap... Superglue on an airplane? I was concerned that the minor seam
leak on my Lycoming O-360 was indicative of case fretting. Now I see that it's a
common problem and nothing to worry about. I guess I'll doublecheck the torque specs
on the case bolts and then get some RTV. It's only enough to cause a sheen on the
case after a long flight, so it's not enough to measure. Only disturbing thing is
what little gets blown on the side of the case goes through the jugs and seems to hit
the exact same spot on the muffler. There's a bit of a "burn oil" stain on it.

I'm not an engine overhauler, but have worked on quite a few. As you
might have figured out, on a Lycoming there is no gasket between the
case halves, just some permatex and a piece of silk thread (at least
that's what it useta be). My understanding is the silk thread is there
to help stop weeping oil leaks between the cases.

The cases that I have seen that have had fretting issues, the fretting
has been "inside" the engine at the bearing supports. I am by no means
saying that they cannot fret at the top seam, just that I am
unfamiliar with same.

I got the infamous TCM super-glue letter when I had a nearly new
TSIO-360 on a Turbo Arrow start weeping along the top seam. Was enuff
to make a big mess. About crapped myself when I read the letter, but
followed the directions and it worked like a charm. The part I liked
(aside from it stopping the leak) was that it was almost invisible.

The super-glue job lasted for about 4 1/2 years (through normal TBO).

regards;

TC