Advice on a couple of problems with the Arrow

[Jack Allison]

Pinging the collective wisdom of the r.a.o folks on a couple of
maintenance issues:

1) Our engine monitor (JPI EDM-700) sometimes indicates sporadic EGT
values for #1 cylinder. It behaves like a sensor or connection issue as
the engine runs fine and the fuel burn is within expected values. #1
CHT value dances up and down fairly rapidly +/- 25 degrees or so of the
value as compared to the other cylinders. The value changes fairly
rapidly (much more so than with the other cylinders). The problem has
come and gone consistent with some sort of wiring issue. Anyone seen a
similar problem? Engine is IO-360.

2) Right brake pedal travel is noticeably more than the left. Stopping
power of both brakes is fine and the fluid level is only slightly down
from the full line. Applying the parking brake while rolling causes the
plane to slightly turn left, consistent with the left brake applying
ahead of the right. No hydraulic leaks anywhere that I can see. Could
it be air in the system that needs to be bled? I'm familiar with this
in cars and have done my share of bleeding brakes and hydraulic
clutches. The airplane domain is new though.

Thanks!

--
Jack Allison
PP-ASEL-IA Student
Arrow N2104T

"When once you have tasted flight, you will forever walk the Earth
with your eyes turned skyward, for there you have been, and there
you will always long to return"
- Leonardo Da Vinci

(Remove the obvious from address to reply via e-mail)

[Bill J]

I have an Arrow ('73) with EDM-700. For problem 1 can you interchange
two of the cylinder probes? If the symptoms appears to move, then it is
a probe or wiring problem, otherwise a real cylinder problem.

Problem 2 might be a bad "dyna-seal"

Jack Allison wrote:
> Pinging the collective wisdom of the r.a.o folks on a couple of
> maintenance issues:
>
> 1) Our engine monitor (JPI EDM-700) sometimes indicates sporadic EGT
> values for #1 cylinder. It behaves like a sensor or connection issue as
> the engine runs fine and the fuel burn is within expected values. #1
> CHT value dances up and down fairly rapidly +/- 25 degrees or so of the
> value as compared to the other cylinders. The value changes fairly
> rapidly (much more so than with the other cylinders). The problem has
> come and gone consistent with some sort of wiring issue. Anyone seen a
> similar problem? Engine is IO-360.
>
> 2) Right brake pedal travel is noticeably more than the left. Stopping
> power of both brakes is fine and the fluid level is only slightly down
> from the full line. Applying the parking brake while rolling causes the
> plane to slightly turn left, consistent with the left brake applying
> ahead of the right. No hydraulic leaks anywhere that I can see. Could
> it be air in the system that needs to be bled? I'm familiar with this
> in cars and have done my share of bleeding brakes and hydraulic
> clutches. The airplane domain is new though.
>
> Thanks!
>

[Jay Honeck]

> 1) Our engine monitor (JPI EDM-700) sometimes indicates sporadic EGT
> values for #1 cylinder. It behaves like a sensor or connection issue as
> the engine runs fine and the fuel burn is within expected values. #1 CHT
> value dances up and down fairly rapidly +/- 25 degrees or so of the value
> as compared to the other cylinders. The value changes fairly rapidly
> (much more so than with the other cylinders). The problem has come and
> gone consistent with some sort of wiring issue. Anyone seen a similar
> problem? Engine is IO-360.

Follow the wiring for the #1 cylinder from the spark plug to the firewall.
We had a similar problem with our #2 cylinder, and it turned out to be a bad
in-line connection/splice. An easy, ten second fix.

> 2) Right brake pedal travel is noticeably more than the left. Stopping
> power of both brakes is fine and the fluid level is only slightly down
> from the full line. Applying the parking brake while rolling causes the
> plane to slightly turn left, consistent with the left brake applying ahead
> of the right. No hydraulic leaks anywhere that I can see. Could it be
> air in the system that needs to be bled?

I've had the exact problem, ever since my last annual, when we replaced a
brake hose. I've had my A&P bleed that brake three times now -- each time
it gets a little better -- but it's still not quite "right." Bleeding
Cherokee brakes properly is a real bitch, involving more than just bleeding
the system down at the wheel. You have to get under the panel, stand on
your head, and bleed the system under there, too, resulting in the
inevitable brake fluid on the carpet, etc.

It's not a great system.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Newps]

Jack Allison wrote:

> Pinging the collective wisdom of the r.a.o folks on a couple of
> maintenance issues:
>
> 1) Our engine monitor (JPI EDM-700) sometimes indicates sporadic EGT
> values for #1 cylinder. It behaves like a sensor or connection issue as
> the engine runs fine and the fuel burn is within expected values. #1
> CHT value dances up and down fairly rapidly +/- 25 degrees or so of the
> value as compared to the other cylinders. The value changes fairly
> rapidly (much more so than with the other cylinders). The problem has
> come and gone consistent with some sort of wiring issue. Anyone seen a
> similar problem? Engine is IO-360.

JPI has the worlds worst way to make connections. If you are stuck with
this lemon you need to take apart the stupid nut, bolt, washer and clean
with a scotchbrite pad or sandpaper. Reinstall. This will fix it for a
while. If you want to solve the problem get an Electronics
International monitor.


>
> 2) Right brake pedal travel is noticeably more than the left. Stopping
> power of both brakes is fine and the fluid level is only slightly down
> from the full line. Applying the parking brake while rolling causes the
> plane to slightly turn left, consistent with the left brake applying
> ahead of the right. No hydraulic leaks anywhere that I can see. Could
> it be air in the system that needs to be bled? I'm familiar with this
> in cars and have done my share of bleeding brakes and hydraulic
> clutches. The airplane domain is new though.
>

Sounds like an air bubble or two in the line. Bleed from the bottom,
not like you bleed your car.

[Montblack]

("Newps" wrote)
> Sounds like an air bubble or two in the line. Bleed from the bottom,
> not like you bleed your car.


What does this mean? Bottom?


My experience with 20 year old cars is:

Pump, pump, pump. Hold. (HELPER - "Like this?")
Open (YOU, at the wheel ...which I thought was the bottom??)

Press slowly on brake pedal (HELPER listening to the radio. "Huh? What?")
Fluid squirts out (YOU - "Turn off the d*** radio.")

Close
Check and refill brake fluid reservoir (which I thought was the top??)

HELPER - "Pump again?"
YOU - "No. Not yet, I'm still filling the....You pumped didn't you?"
HELPER - "Sorry."
YOU - "Turn off that d*** radio."

Rinse and repeat :-)

How do you do it in planes?

Thanks


Montblack

[Ron Wanttaja]

On Mon, 16 May 2005 09:29:45 -0500, "Montblack"
> wrote:

>("Newps" wrote)
>> Sounds like an air bubble or two in the line. Bleed from the bottom,
>> not like you bleed your car.
>
>What does this mean? Bottom?

Go to the auto-parts store and buy a cheap pump-type oil can and a couple of
feet of clear nylon tube that fits over the spout.

Fill the can with aircraft brake fluid. Go to the airplane, and remove the cap
from the brake master cylinder. Go to the wheel and look at the brake assembly.
There should be a metal nipple with a screw in the end as a plug. The nipple is
about the same OD as the ID of the nylon tube on the end of the oil can.

Pump the oil can until the nylon tube is full of hydraulic fluid. Unscrew the
plug on the end of the nipple and slide the tube over it.

Start pumping. You're now forcing any air upwards towards the master cylinder,
filling the brake cylinder and brake line with an uninterrupted stream of fluid.

Have a friend inside the plane, watching the master cylinder to shout when the
fluid reaches the top (on my plane, I can actually sit by the wheel, reach up,
and put my finger in the open hole). When the master cylinder is full, have him
cap off the master cylinder, then pull the nylon tube off from the nipple and
re-insert the plug screw.

Ron Wanttaja

[[email protected]]

LOL! How true... :)
-Cory

Montblack > wrote:
: ("Newps" wrote)
: > Sounds like an air bubble or two in the line. Bleed from the bottom,
: > not like you bleed your car.


: What does this mean? Bottom?


: My experience with 20 year old cars is:

: Pump, pump, pump. Hold. (HELPER - "Like this?")
: Open (YOU, at the wheel ...which I thought was the bottom??)

: Press slowly on brake pedal (HELPER listening to the radio. "Huh? What?")
: Fluid squirts out (YOU - "Turn off the d*** radio.")

: Close
: Check and refill brake fluid reservoir (which I thought was the top??)

: HELPER - "Pump again?"
: YOU - "No. Not yet, I'm still filling the....You pumped didn't you?"
: HELPER - "Sorry."
: YOU - "Turn off that d*** radio."

: Rinse and repeat :-)

: How do you do it in planes?

: Thanks


: Montblack

--

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

[[email protected]]

Montblack > wrote:
: How do you do it in planes?

I believe he was talking about bottom-feeding bleeding. Rig up a pump to a
can of fluid and connect it to the bleeder fitting at the wheel. Force the fluid
backwards through the sytem (and keep the can under the cowling from overflowing).
That should help in chasing the air out.

My mechanic has done some work on a couple of them, and says that there's a
small washer/valve in the toebrakes that generally needs replacement. It does sound
like a bitch, and something I should do before we get our new carpet. Unlikely it'll
happen before then, though.

-Cory

--

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

[[email protected]]

Regarding problem #1, you do not make it clear whether the intermittent
fluctuations in EGT and CHT readings coincide. If they do,then I would
suspect the possibility of an intermittent partial clogging of the injector
due to some small bit of debris. A problem with both the EGT and CHT probes
for the same cylinder seems like a bit of a coincidence to me (but by no
means out of the question).

Regarding problem #2, sure sounds like air in the right brake. Is this
something new, or has the problem been there since you bought the plane?

--
-Elliott Drucker

[Jon Kraus]

Jack,

We had the same problems on the Mooney... For # 1... wait a minute...
Scratch the # 1 thing... We have an EI anlyzer... It works much better
then the EDM-700 (just kidding, it does work nice though)...

For problem # 2 we had a bad O-ring on the right master cylinder
allowing air to get in.. It was a 61.00 repair. 1.00 for the o-ring and
1 hour labor!!

Jon Kraus
'79 Mooney 201

Jack Allison wrote:
> Pinging the collective wisdom of the r.a.o folks on a couple of
> maintenance issues:
>
> 1) Our engine monitor (JPI EDM-700) sometimes indicates sporadic EGT
> values for #1 cylinder. It behaves like a sensor or connection issue as
> the engine runs fine and the fuel burn is within expected values. #1
> CHT value dances up and down fairly rapidly +/- 25 degrees or so of the
> value as compared to the other cylinders. The value changes fairly
> rapidly (much more so than with the other cylinders). The problem has
> come and gone consistent with some sort of wiring issue. Anyone seen a
> similar problem? Engine is IO-360.
>
> 2) Right brake pedal travel is noticeably more than the left. Stopping
> power of both brakes is fine and the fluid level is only slightly down
> from the full line. Applying the parking brake while rolling causes the
> plane to slightly turn left, consistent with the left brake applying
> ahead of the right. No hydraulic leaks anywhere that I can see. Could
> it be air in the system that needs to be bled? I'm familiar with this
> in cars and have done my share of bleeding brakes and hydraulic
> clutches. The airplane domain is new though.
>
> Thanks!
>