Cessna 210 fuel drip

[John Clonts]

We have a 78 Centurion which has developed a fuel "drip" underneath,
from some kind of drain tube protruding from under the fuselage on the
left side, about 12-18" behind the nose wheel opening. I am trying to
figure out what this line is coming from or is for. It is not the
fuel strainer discharge tube, nor is it the sump "quick drain".
Looking at a parts manual for the aircraft, it seems that it may be
some kind of vent or drain line coming from the fuel selector valve?
The drip is about 1 drip per minute, which keeps a wet spot about 5"
in diameter on the hangar floor.

I have discussed it with our mechanic, but only by phone since he is
60nm away, and so far he can't remember what it might be but "we would
just have to look at it".

Is anyone here familiar enough with this installation to shed some
light on it for me? Is this coming from the fuel selector? If so,
does the drip indicate the the selector needs to be serviced or
rebuilt?

Thanks!
John Clonts
Temple, Texas
N7NZ

[John[_9_]]

On Mar 10, 2:53*pm, John Clonts > wrote:
> We have a 78 Centurion which has developed a fuel "drip" underneath,
> from some kind of drain tube protruding from under the fuselage on the
> left side, about 12-18" behind the nose wheel opening. *I am trying to
> figure out what this line is coming from or is for. *It is not the
> fuel strainer discharge tube, nor is it the sump "quick drain".
> Looking at a parts manual for the aircraft, it seems that it may be
> some kind of vent or drain line coming from the fuel selector valve?
> The drip is about 1 drip per minute, which keeps a wet spot about 5"
> in diameter on the hangar floor.
>
> I have discussed it with our mechanic, but only by phone since he is
> 60nm away, and so far he can't remember what it might be but "we would
> just have to look at it".
>
> Is anyone here familiar enough with this installation to shed some
> light on it for me? *Is this coming from the fuel selector? *If so,
> does the drip indicate the the selector needs to be serviced or
> rebuilt?
>
> Thanks!
> John Clonts
> Temple, Texas
> N7NZ

In all likelihood that is the drain mast for the electric fuel pump.
If it is leaking that means the pump seals have failed and it is
possible that fuel will wash the lubricant for the pump bearings.
Looks like a new pump for you.

John Dupre'

[[email protected]]

On Mar 11, 9:58 am, John > wrote:
> On Mar 10, 2:53 pm, John Clonts > wrote:
>
>
>
> > We have a 78 Centurion which has developed a fuel "drip" underneath,
> > from some kind of drain tube protruding from under the fuselage on the
> > left side, about 12-18" behind the nose wheel opening. I am trying to
> > figure out what this line is coming from or is for. It is not the
> > fuel strainer discharge tube, nor is it the sump "quick drain".
> > Looking at a parts manual for the aircraft, it seems that it may be
> > some kind of vent or drain line coming from the fuel selector valve?
> > The drip is about 1 drip per minute, which keeps a wet spot about 5"
> > in diameter on the hangar floor.
>
> > I have discussed it with our mechanic, but only by phone since he is
> > 60nm away, and so far he can't remember what it might be but "we would
> > just have to look at it".
>
> > Is anyone here familiar enough with this installation to shed some
> > light on it for me? Is this coming from the fuel selector? If so,
> > does the drip indicate the the selector needs to be serviced or
> > rebuilt?
>
> > Thanks!
> > John Clonts
> > Temple, Texas
> > N7NZ
>
> In all likelihood that is the drain mast for the electric fuel pump.
> If it is leaking that means the pump seals have failed and it is
> possible that fuel will wash the lubricant for the pump bearings.
> Looks like a new pump for you.
>
> John Dupre'

Some Cessnas had an intake manifold drain to remove surplus fuel
if the engine became flooded from overpriming.

If this 210 is carbureted, the carb float valve is leaking. If
it's injected, the leak is from something else, not the manifold.

Dan

[John[_9_]]

On Mar 12, 10:33*pm, wrote:
> On Mar 11, 9:58 am, John > wrote:
>
>
>
>
>
> > On Mar 10, 2:53 pm, John Clonts > wrote:
>
> > > We have a 78 Centurion which has developed a fuel "drip" underneath,
> > > from some kind of drain tube protruding from under the fuselage on the
> > > left side, about 12-18" behind the nose wheel opening. *I am trying to
> > > figure out what this line is coming from or is for. *It is not the
> > > fuel strainer discharge tube, nor is it the sump "quick drain".
> > > Looking at a parts manual for the aircraft, it seems that it may be
> > > some kind of vent or drain line coming from the fuel selector valve?
> > > The drip is about 1 drip per minute, which keeps a wet spot about 5"
> > > in diameter on the hangar floor.
>
> > > I have discussed it with our mechanic, but only by phone since he is
> > > 60nm away, and so far he can't remember what it might be but "we would
> > > just have to look at it".
>
> > > Is anyone here familiar enough with this installation to shed some
> > > light on it for me? *Is this coming from the fuel selector? *If so,
> > > does the drip indicate the the selector needs to be serviced or
> > > rebuilt?
>
> > > Thanks!
> > > John Clonts
> > > Temple, Texas
> > > N7NZ
>
> > In all likelihood that is the drain mast for the electric fuel pump.
> > If it is leaking that means the pump seals have failed and it is
> > possible that fuel will wash the lubricant for the pump bearings.
> > Looks like a new pump for you.
>
> > John Dupre'
>
> * * *Some Cessnas had an intake manifold drain to remove surplus fuel
> if the engine became flooded from overpriming.
>
> * * *If this 210 is carbureted, the carb float valve is leaking. If
> it's injected, the leak is from something else, not the manifold.
>
> * * * Dan- Hide quoted text -
>
> - Show quoted text -


The key is that the leaking line is 12 to 18 inches behind the nose
wheel well on the left side. That is where the electic fuel boost
pump is located.

John Dupre'

[John Clonts]

On Mar 14, 6:47*am, John > wrote:
> On Mar 12, 10:33*pm, wrote:
>
>
>
>
>
> > On Mar 11, 9:58 am, John > wrote:
>
> > > On Mar 10, 2:53 pm, John Clonts > wrote:
>
> > > > We have a 78 Centurion which has developed a fuel "drip" underneath,
> > > > from some kind of drain tube protruding from under the fuselage on the
> > > > left side, about 12-18" behind the nose wheel opening. *I am trying to
> > > > figure out what this line is coming from or is for. *It is not the
> > > > fuel strainer discharge tube, nor is it the sump "quick drain".
> > > > Looking at a parts manual for the aircraft, it seems that it may be
> > > > some kind of vent or drain line coming from the fuel selector valve?
> > > > The drip is about 1 drip per minute, which keeps a wet spot about 5"
> > > > in diameter on the hangar floor.
>
> > > > I have discussed it with our mechanic, but only by phone since he is
> > > > 60nm away, and so far he can't remember what it might be but "we would
> > > > just have to look at it".
>
> > > > Is anyone here familiar enough with this installation to shed some
> > > > light on it for me? *Is this coming from the fuel selector? *If so,
> > > > does the drip indicate the the selector needs to be serviced or
> > > > rebuilt?
>
> > > > Thanks!
> > > > John Clonts
> > > > Temple, Texas
> > > > N7NZ
>
> > > In all likelihood that is the drain mast for the electric fuel pump.
> > > If it is leaking that means the pump seals have failed and it is
> > > possible that fuel will wash the lubricant for the pump bearings.
> > > Looks like a new pump for you.
>
> > > John Dupre'
>
> > * * *Some Cessnas had an intake manifold drain to remove surplus fuel
> > if the engine became flooded from overpriming.
>
> > * * *If this 210 is carbureted, the carb float valve is leaking. If
> > it's injected, the leak is from something else, not the manifold.
>
> > * * * Dan- Hide quoted text -
>
> > - Show quoted text -
>
> The key is that the leaking line is 12 to 18 inches behind the nose
> wheel well on the left side. *That is where the electic fuel boost
> pump is located.
>
> John Dupre'- Hide quoted text -
>

Yes, I think you are right. This gibes with what I see now in the
parts and service manuals. My mechanic tells me that it may simply be
due to lack of use, over the 4 months that it has sat while our engine
was being rebuilt. Last time I checked it it was dripping slower than
it had been before...

Thanks!
John