brake bleeding

[pintlar]

Marchetti SA1
yr unknown.
Can anyone tell me if one has to vacumn at the wheel cylinders and apply
fluid at the brake pedal cylinder?
Or is it best (easier) to vacumn at the brake pedal and insert fluid at the
wheel?
This is for a friend and he has no books for his plane.
Also, what should the cylinder head pressure be on a 4 cylinder Lyc 150 or
160 hp?
.. . in advance . . .thanks.

[cavelamb[_2_]]

kimda makes ya wonder, doesn't it...

[Ron Wanttaja[_2_]]

Pintlar wrote:
> Marchetti SA1
> yr unknown.
> Can anyone tell me if one has to vacumn at the wheel cylinders and apply
> fluid at the brake pedal cylinder?
> Or is it best (easier) to vacumn at the brake pedal and insert fluid at the
> wheel?
> This is for a friend and he has no books for his plane.
> Also, what should the cylinder head pressure be on a 4 cylinder Lyc 150 or
> 160 hp?
> . . in advance . . .thanks.

Standard practice is to open the cap at the master cylinder, and pump
brake fluid in from the wheel cylinder. Most wheel cylinders include a
small valve/nipple that will accept a small nylon tube. For pumping the
brake fluid, I use an inexpensive hand pump that's usually used for oil.

Aircraft engines aren't normally testing for cylinder head pressure the
same way car engines are. They are tested for leakage using an air
compressor and a specialized differential pressure gauge. See:

http://www.littleflyers.com/engcomp.htm

Ron Wanttaja

[pintlar]

Many many thanks again, Stealth Pilot.
.. . . I don't even feel I need the Cessna manual as your description was so
clear and concise. I feel we'll get it done now on the first pass (4th). I
soldered up a vacumn bottle to hold the fill fluid, and a recovery bottle to
use at the (refrig) vacumn pump to recover the fluid.
.. . . Now the biggest problem I see is the terribly small awkward space
under the dash. And the fact that we have to do it a minimum of four times
to be sure to purge all the air from all 4 master cylinders.
Again, thanks. . . . . charlie

[Stealth Pilot[_2_]]

On Thu, 1 Apr 2010 05:02:07 -0600, "Pintlar" >
wrote:

>Many many thanks again, Stealth Pilot.
>. . . I don't even feel I need the Cessna manual as your description was so
>clear and concise. I feel we'll get it done now on the first pass (4th). I
>soldered up a vacumn bottle to hold the fill fluid, and a recovery bottle to
>use at the (refrig) vacumn pump to recover the fluid.
>. . . Now the biggest problem I see is the terribly small awkward space
>under the dash. And the fact that we have to do it a minimum of four times
>to be sure to purge all the air from all 4 master cylinders.
> Again, thanks. . . . . charlie
>

hang on a second charlie that doesnt quite make sense.

4????? master cylinders.

if you have braking from both sides of the aircraft, pilot and
passenger/co-pilot, there usually arent 4 master cylinders.

what you should find is that one side will have the reservoirs and the
other side will have a thinner pair of master cylinders. these thinner
ones are the same cylinders but without the reservoirs.

the way it should be connected is that the master cylinder with the
reservoir will be piped with flexible hydraulic hose to the top of the
cylinder without the reservoir. this cylinder then connects to the
slave unit in the wheel. you should be able to confirm this quickly by
looking at the hydraulic line down to the leg. there should only be
one each side.

this is how it works. remember the loose piston I described before.
that is the secret.
in the cylinder without the reservoir when the pilot pushes the toe
brake the rod seals the top of the loose piston and pushes it down
activating the brakes.
if the pilot with the reservoirs also pushes on the brakes his rod
also moves down and seals his loose piston and puts pressure into the
line to the other brakes. if his braking pressure is higher than the
pressure in the non reservoir side his pressure will actually unseat
the other loose piston and push more hydraulic fluid past the unseated
piston and activate the brakes with more force.

when the pilot without the reservoirs takes his feet off the brakes
the piston unseats and the pressure becomes that in the upstream line.
(this means that the pilot can press the brakes and the brakes work)

when the pilot with the reservoirs also takes his feet off the brakes
the entire system depressurises to local atmospheric.

so... with both brakes off you should be able to ignore the presence
of the non reservoir cylinders and just bleed and fill the system as
though there was only the reservoir master cylinders.

this brake arrangement is unique to aviation. I think it is a damn
cunning design!

Stealth Pilot (who illegally fixed his brakes 6 years ago and has 19
years before they need to be done again)

[Peter Dohm]

"Pintlar" > wrote in message
...
> Many many thanks again, Stealth Pilot.
> . . . I don't even feel I need the Cessna manual as your description was
> so clear and concise. I feel we'll get it done now on the first pass
> (4th). I soldered up a vacumn bottle to hold the fill fluid, and a
> recovery bottle to use at the (refrig) vacumn pump to recover the fluid.
> . . . Now the biggest problem I see is the terribly small awkward space
> under the dash. And the fact that we have to do it a minimum of four
> times to be sure to purge all the air from all 4 master cylinders.
> Again, thanks. . . . . charlie
>
Presuming that you are working on a type certified aircraft, which includes
a 100 series Cessna, and that the aircraft is registered in the United
States; there are a couple of important rules that still apply--even when
you are performing those maintenance tasks that are permissible for the
owner to perform...

I don't recall the specific language, but I do recall that you are required
to possess the appropriate documentation (manual) and to have reviewed it as
needed and that you are also required to use any tools and equipment that a
certificated mechanic would be required to use.

I'm really not trying to be a prig, but there were quite a series of
discussions between a couple of FAA safety inspectors and some of the owners
at one of the local airports near where I live--and about a hundred dollars
worth of "special" tools and a couple of manuals would have saved everyone
involved a lot of unproductive time and effort.

Peter

[Brian Whatcott]

Peter Dohm wrote:
> "Pintlar" > wrote in message
> ...
>> Many many thanks again, Stealth Pilot.
>> . . . I don't even feel I need the Cessna manual as your description was
>> so clear and concise. I feel we'll get it done now on the first pass
>> (4th). I soldered up a vacumn bottle to hold the fill fluid, and a
>> recovery bottle to use at the (refrig) vacumn pump to recover the fluid./snip/

> I'm really not trying to be a prig, but there were quite a series of
> discussions between a couple of FAA safety inspectors and some of the owners
> at one of the local airports near where I live--and about a hundred dollars
> worth of "special" tools and a couple of manuals would have saved everyone
> involved a lot of unproductive time and effort.
>
> Peter
>
>
>
....not to mention the vacuum pump, the bottle, this and that, which I
suspect is quite unnecessary....

Brian W

[Capt. Geoffrey Thorpe]

"Pintlar" > wrote in message
...
> Now I'm looking for the Cessna 100 parts manual.
> Again I thank you. charlie


http://www.micro-tools.net/pdf/Cessna/index.html

--
Geoff
The Sea Hawk at Wow Way d0t Com
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate.

[pintlar]

"Stealth Pilot" > wrote in message >
> hang on a second charlie that doesnt quite make sense.
>
> 4????? master cylinders.
>
> if you have braking from both sides of the aircraft, pilot and
> passenger/co-pilot, there usually arent 4 master cylinders.
******************
On this craft there are 4 identical cylinders, one behind each of the
pedals. The two left foot cylinder lines go to a 'T' connection and the
same for the right pedal cylinders to another 'T'. Each 'T' output line
then respectively goes to one brake disc piston.
.. . .Again thank you for all the insight. I guess my friend will have to
find a manual for his craft somewhere.
******************
> what you should find is that one side will have the reservoirs and the
> other side will have a thinner pair of master cylinders. (SAME SIZE HERE)
> these thinner
> ones are the same cylinders but without the reservoirs.
>
> the way it should be connected is that the master cylinder with the
> reservoir will be piped with flexible hydraulic hose to the top of the
> cylinder without the reservoir. this cylinder then connects to the
> slave unit in the wheel. you should be able to confirm this quickly by
> looking at the hydraulic line down to the leg. there should only be
> one each side.
>
> this is how it works. remember the loose piston I described before.
> that is the secret.
> in the cylinder without the reservoir when the pilot pushes the toe
> brake the rod seals the top of the loose piston and pushes it down
> activating the brakes.
> if the pilot with the reservoirs also pushes on the brakes his rod
> also moves down and seals his loose piston and puts pressure into the
> line to the other brakes. if his braking pressure is higher than the
> pressure in the non reservoir side his pressure will actually unseat
> the other loose piston and push more hydraulic fluid past the unseated
> piston and activate the brakes with more force.
>
> when the pilot without the reservoirs takes his feet off the brakes
> the piston unseats and the pressure becomes that in the upstream line.
> (this means that the pilot can press the brakes and the brakes work)
>
> when the pilot with the reservoirs also takes his feet off the brakes
> the entire system depressurises to local atmospheric.
>
> so... with both brakes off you should be able to ignore the presence
> of the non reservoir cylinders and just bleed and fill the system as
> though there was only the reservoir master cylinders.
>
> this brake arrangement is unique to aviation. I think it is a damn
> cunning design!
>
> Stealth Pilot (who illegally fixed his brakes 6 years ago and has 19
> years before they need to be done again)
>

[Stealth Pilot[_2_]]

On Fri, 2 Apr 2010 15:49:25 -0600, "Pintlar" >
wrote:

>
>"Stealth Pilot" > wrote in message >
>> hang on a second charlie that doesnt quite make sense.
>>
>> 4????? master cylinders.
>>
>> if you have braking from both sides of the aircraft, pilot and
>> passenger/co-pilot, there usually arent 4 master cylinders.
>******************
>On this craft there are 4 identical cylinders, one behind each of the
>pedals. The two left foot cylinder lines go to a 'T' connection and the
>same for the right pedal cylinders to another 'T'. Each 'T' output line
>then respectively goes to one brake disc piston.
>. . .Again thank you for all the insight. I guess my friend will have to
>find a manual for his craft somewhere.
>******************

I would encourage him to locate the manual !

as described, if it is using the common gerdes or cleveland 10-35
(they are the same, gerdes is older) that brake setup shouldnt work.

so either the designer has done something different in the brake setup
which your friend will need to understand or someone has made a
modification that is wrong. in either case your friend would benefit
by having the applicable information.

btw what type of aircraft is it?

Stealth Pilot

[Ed]

On Sun, 04 Apr 2010 09:04:08 GMT, Stealth Pilot
> wrote:


>as described, if it is using the common gerdes or cleveland 10-35
>(they are the same, gerdes is older) that brake setup shouldnt work.
>
>so either the designer has done something different in the brake setup
>which your friend will need to understand or someone has made a
>modification that is wrong. in either case your friend would benefit
>by having the applicable information.
>
>btw what type of aircraft is it?
>
>Stealth Pilot

is it possible he has a separate resevoir on the firewall?

[Brian Whatcott]

Orval Fairbairn wrote:
> In article >,
> brian whatcott > wrote:
>
>> Siai Marchetti: This is a fast good looking light aircraft. I was
>> surprised to find there are plans available out there (If I remember
>> right...)
>>
>
> The plans are for the Falco, a wooden design, smaller and similar in
> looks to the SF-260.
>

Ah yes. I heard of take off accidents to one of each of these types
- an attempt to take off over wet grass in each case...

Brian W

[jerry wass]

brian whatcott wrote:
> Orval Fairbairn wrote:
>> In article >,
>> brian whatcott > wrote:
>>
>>> Siai Marchetti: This is a fast good looking light aircraft. I was
>>> surprised to find there are plans available out there (If I remember
>>> right...)
>>>
>>
>> The plans are for the Falco, a wooden design, smaller and similar in
>> looks to the SF-260.
>>
>
> Ah yes. I heard of take off accidents to one of each of these types
> - an attempt to take off over wet grass in each case...
>
> Brian W

Did the wet grass contribute to the accident ?? Jerry W

[Orval Fairbairn[_2_]]

In article >,
brian whatcott > wrote:

> Orval Fairbairn wrote:
> > In article >,
> > brian whatcott > wrote:
> >
> >> Siai Marchetti: This is a fast good looking light aircraft. I was
> >> surprised to find there are plans available out there (If I remember
> >> right...)
> >>
> >
> > The plans are for the Falco, a wooden design, smaller and similar in
> > looks to the SF-260.
> >
>
> Ah yes. I heard of take off accidents to one of each of these types
> - an attempt to take off over wet grass in each case...
>
> Brian W

Sounds like poor pilot technique.

--
Remove _'s from email address to talk to me.

[Brian Whatcott]

Jerry Wass wrote:
> brian whatcott wrote:
>> Orval Fairbairn wrote:
>>> In article >,
>>> brian whatcott > wrote:
>>>
>>>> Siai Marchetti: This is a fast good looking light aircraft. I was
>>>> surprised to find there are plans available out there (If I remember
>>>> right...)
>>>>
>>>
>>> The plans are for the Falco, a wooden design, smaller and similar in
>>> looks to the SF-260.
>>>
>>
>> Ah yes. I heard of take off accidents to one of each of these types
>> - an attempt to take off over wet grass in each case...
>>
>> Brian W
>
> Did the wet grass contribute to the accident ?? Jerry W

Apparently, the wet grass provided a surprisingly draggy surface, so
that a hedge appeared before daylight....

Brian W

[jerry wass]

brian whatcott wrote:
> Jerry Wass wrote:
>> brian whatcott wrote:
>>> Orval Fairbairn wrote:
>>>> In article >,
>>>> brian whatcott > wrote:
>>>>
>>>>> Siai Marchetti: This is a fast good looking light aircraft. I was
>>>>> surprised to find there are plans available out there (If I
>>>>> remember right...)
>>>>>
>>>>
>>>> The plans are for the Falco, a wooden design, smaller and similar in
>>>> looks to the SF-260.
>>>>
>>>
>>> Ah yes. I heard of take off accidents to one of each of these types
>>> - an attempt to take off over wet grass in each case...
>>>
>>> Brian W
>>
>> Did the wet grass contribute to the accident ?? Jerry W
>
> Apparently, the wet grass provided a surprisingly draggy surface, so
> that a hedge appeared before daylight....
>
> Brian W
Thanks, Jerry