Constant speed prop oil leak

I was pre-flighting my plane today until I saw this long red strip
running down the entire length of my prop with a small puddle at the
bottom!!! I hadn't seen it before. It was the first time flying in
three weeks. I was at the plane last week, and didn't see anything,
but the again, I wasn't looking for anything either.......

Needless to say.. no mechanics aaround, I didn't fly it. I cleaned
off the area & prop with gas, and then started it up to see what may
happen. Sure enough, it sprayed a small amount of red hydraulic oil
on the prop and on the top cowl.


Any ideas how serious this is? Am I looking at a complete prop
overhaul? Could it be as simple as a seal that the A &P can replace?
Something in between ???

Thanks in advance !


Don Paquette
PP-ASEL
N9723X

"DP" wrote in message
...
[...] Sure enough, it sprayed a small amount of red hydraulic oil
on the prop and on the top cowl.

Odd. I would've assumed a 210 would have a similar prop governor design to
other piston singles, using engine oil to control the prop.

Granted, I'm not familiar with the 210 systems. But are you sure that the
hydraulic fluid is coming from the prop governor? Alternatively, are you
sure it's hydraulic fluid? Or can you (or anyone else) confirm that the 210
prop governing system uses hydraulic fluid rather than engine oil?

Pete

"Peter Duniho" wrote in message
...
"DP" wrote in message
...
[...] Sure enough, it sprayed a small amount of red hydraulic oil
on the prop and on the top cowl.

Odd. I would've assumed a 210 would have a similar prop governor design
to
other piston singles, using engine oil to control the prop.

They do. The guts of the prop use a red colored oil so you know when they
start to leak. All constant speed props do this.

No, not all.

Newps wrote:

"Peter Duniho" wrote in message
...

"DP" wrote in message
. ..

[...] Sure enough, it sprayed a small amount of red hydraulic oil
on the prop and on the top cowl.

Odd. I would've assumed a 210 would have a similar prop governor design

to

other piston singles, using engine oil to control the prop.


They do. The guts of the prop use a red colored oil so you know when they
start to leak. All constant speed props do this.

"Newps" wrote:


"Peter Duniho" wrote in message
...
"DP" wrote in message
...
[...] Sure enough, it sprayed a small amount of red hydraulic oil
on the prop and on the top cowl.

Odd. I would've assumed a 210 would have a similar prop governor
design
to
other piston singles, using engine oil to control the prop.

They do. The guts of the prop use a red colored oil so you know when
they start to leak. All constant speed props do this.

I checked into this awhile back and learned the same thing. The McCauley
props didn't have it originally, but there's now a mandatory service
bulletin to fill the hub with the red oil/grease. This provides an
indicator of leaks, but also causes the prop to need service more often. I
was told the grease would stay in place for about 5 years, and then the
prop would need to be overhauled, or resealed again.

Mike

There was an AD several dozen years ago that affected [almost] all McCauley
props. The idea was to fill the hub with red hydraulic fluid so that any leaks
would be immediately apparent to the most casual observer.

Yours is leaking. Seal? Probably. Simple? Nothing on a CS prop is simple.
And, according to part 43, an A&P can't get into the guts of a CS prop by
specific reference.

Sending it to a prop shop is going to be painful, but probably not as painful as
you might expect. Crating and shipping is the royal pain in the ass, and if you
don't mind a crosscountry in the ground vehicle to the prop shop, you are not
looking at a tremendous amount of $$$.

On the other hand, they have to pull it apart anyway, so why not just do the
overhaul for the price of a couple of hours of labor and some dollar parts?

Just my 8% of two bits...

Jim



-
-Any ideas how serious this is? Am I looking at a complete prop
-overhaul? Could it be as simple as a seal that the A &P can replace?
-Something in between ???


Jim Weir (A&P/IA, CFI, & other good alphabet soup)
VP Eng RST Pres. Cyberchapter EAA Tech. Counselor
http://www.rst-engr.com

On Sun, 18 Apr 2004 17:26:58 -0600, "Newps"
wrote:


"Peter Duniho" wrote in message
...
"DP" wrote in message
...
[...] Sure enough, it sprayed a small amount of red hydraulic oil
on the prop and on the top cowl.

Odd. I would've assumed a 210 would have a similar prop governor design
to
other piston singles, using engine oil to control the prop.

They do. The guts of the prop use a red colored oil so you know when they
start to leak. All constant speed props do this.


AFAIK, all the McCauley's (oil-filled hubs) use the red oil.
Hartzell's have a "dry" hub, and throw grease. A compact hub Hartzell
throwing engine oil (not red) is rare, but it can happen.

Don't know if anybody else mentioned it, but if you see red oil, you
really oughta get it looked at ASAP.

TC

In article ,
Jim Weir wrote:
There was an AD several dozen years ago that affected [almost] all McCauley
props. The idea was to fill the hub with red hydraulic fluid so that any leaks
would be immediately apparent to the most casual observer.

How long does such a prop last if it starts leaking in flight? I've
seen people put up with grease-spitting props for a long time. Even fly
it to the overhaul location. Doesn't seem like you can do that with
oil.

--
Ben Jackson

http://www.ben.com/

On Sun, 18 Apr 2004 18:17:24 -0700, Jim Weir wrote:

snipped for length, not for content.

On the other hand, they have to pull it apart anyway, so why not just do the
overhaul for the price of a couple of hours of labor and some dollar parts?

Was lucky to have a prop shop next door for a few years, will only add
a few thoughts.

On the older McCauley's, at overhaul, the blades have to be unscrewed
from the ferrules (sp?) and inspected. The longer it has been since
this has been done, the more difficult it is, and the more likely you
are to find problems. The newer McCauley hub designs are stone-simple
and relatively easy to o-haul. The only real down side would be blade
rework/inspection (material removed working toward min specs). I would
agree that on a McCauley in most cases overhaul would be the way to
go.

If you've got a common compact hub Hartzell (not applicable in this
particular case), "overhaul" means they have to roll the blade shanks
near the butt and then polish to remove the roll "marks". There is
also a min. diameter for the blade shanks. As above, there are also
requirements for blade rework (accompanied by another set of min
specs). For 91 operators, I've always recommended a 5 year (max)
tear-down, hub corrosion inspection, and re-seal.

FWIW, there were always a lot fewer scrapped parts coming out of the
McCauley end of the shop than the Hartzell end. Corrosion from
infrequent inspection/improper lubrication being the primary issue.

Never saw a corrosion problem inside the Hartzell props on "working"
airplanes (greased every 100 hrs/2-3 months, o-hauled every 3-4
years). Always thought that a grease job every 100 hrs/6 months
(regardless of hours in the air) would be a good idea for relatively
in-frequent flyers.

TC

snip

On Mon, 19 Apr 2004 01:11:32 GMT, Mike Adams
wrote:

"Newps" wrote:


"Peter Duniho" wrote in message
...
"DP" wrote in message
...
[...] Sure enough, it sprayed a small amount of red hydraulic oil
on the prop and on the top cowl.

Odd. I would've assumed a 210 would have a similar prop governor
design
to
other piston singles, using engine oil to control the prop.

They do. The guts of the prop use a red colored oil so you know when
they start to leak. All constant speed props do this.

I checked into this awhile back and learned the same thing. The McCauley
props didn't have it originally, but there's now a mandatory service
bulletin to fill the hub with the red oil/grease. This provides an
indicator of leaks, but also causes the prop to need service more often. I
was told the grease would stay in place for about 5 years, and then the
prop would need to be overhauled, or resealed again.



Well, this is starting to make sense then.....it's been 10 years since
the last prop overhaul......


Mike

Don Paquette
PP-ASEL
N9723X