Fairchild Club Forum

'Is it worth the effort to try to fill the Hayes brake expander tubes with fluid, thereby expelling all the air in them, before installing the tubes?

I'm getting ready to get my PT-26s brakes back on and noted the stem for the tubes is not near the top where air would tend to accumulate.

Also - I just reviewed the past couple years messages on the Hayes brakes and the landing gear struts and have concluded that using DOT 5 in the brake system and 5606 in the landing gear struts is a good way to go. Also using something like TiteSeal, especially on the copper gaskets on the banjo fittings, will reduce the likelihood of brake fluid leaks. Do these ideas sound reasonable?

Is there something else I should know about before wading into this?

Charles'

'very good summary!

go!



)

Airy



F-AZCI SN#998 UC-61K ..still for sale...



To: fairchildclub@yahoogroups.com
From: ccm2@sbcglobal.net
Date: Tue, 6 Oct 2009 21:33:01 +0000
Subject: [fairchildclub] bleeding expander tubes





Is it worth the effort to try to fill the Hayes brake expander tubes with fluid, thereby expelling all the air in them, before installing the tubes?

I'm getting ready to get my PT-26s brakes back on and noted the stem for the tubes is not near the top where air would tend to accumulate.

Also - I just reviewed the past couple years messages on the Hayes brakes and the landing gear struts and have concluded that using DOT 5 in the brake system and 5606 in the landing gear struts is a good way to go. Also using something like TiteSeal, especially on the copper gaskets on the banjo fittings, will reduce the likelihood of brake fluid leaks. Do these ideas sound reasonable?

Is there something else I should know about before wading into this?

Charles









_________________________________________________________________
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[Non-text portions of this message have been removed]'

'Try pumping fluid through the expander tube up to the reservoir with the wheel on the axle.  Usually it makes brake bleeding easier.  Looks like you have the brakes and struts covered.
 Mike


"He's crazy Lou, he builds toy airplanes".
- Capt. Frank Towns
Flight of the Phoenix




________________________________
From: ccmueller001
To: fairchildclub@yahoogroups.com
Sent: Tuesday, October 6, 2009 5:33:01 PM
Subject: [fairchildclub] bleeding expander tubes

 
Is it worth the effort to try to fill the Hayes brake expander tubes with fluid, thereby expelling all the air in them, before installing the tubes?

I'm getting ready to get my PT-26s brakes back on and noted the stem for the tubes is not near the top where air would tend to accumulate.

Also - I just reviewed the past couple years messages on the Hayes brakes and the landing gear struts and have concluded that using DOT 5 in the brake system and 5606 in the landing gear struts is a good way to go. Also using something like TiteSeal, especially on the copper gaskets on the banjo fittings, will reduce the likelihood of brake fluid leaks. Do these ideas sound reasonable?

Is there something else I should know about before wading into this?

Charles




[Non-text portions of this message have been removed]'

'Charles,



Interesting you bring up this discussion. I just completed rebuilding my
master cylinders and flushing my brake system with denatured alcohol. I
used DOT 5 Fluid and filled the system from the bottom up. As you say there
is no real good way to bleed the expander tubes that I have found. I have
found that after I fly and use the brakes for a couple of time, I find a
little air in the system near the wheels. I drain the fluid to remove the
air bubbles. I replenish the fluid in the reservoir. I fly it and do this
a couple of time until I no longer find any air in the system. I am
guessing that some of the air in the expander tube works its way out into
the brake line near the wheel and is removed by draining some fluid. I have
had no leak problem with the DOT 5 fluid.



I am still very new to the expander brakes and certainly don't feel I am
much of a source for information. My brakes are now working pretty well. I
still have to pump them a bit. I am thinking my brake blocks may be worn
some so the expander tubes are having trouble pushing them out against the
drum.



I would be interested in hearing from some owners with these expander tube
brakes. Is it normal to have to pump the brakes? With new blocks do the
brakes work without having to pump them? In my case it seems like the
amount of fluid moved by the master cylinders is not enough to expand the
tubes to push out the blocks hard enough against the drums without pumping
them a few times. Is this normal? With all the air removed from the system
can one expect them to work with out pumping?



Thanks for anyone's comments.



Charles, I am also using 5606 in the main and tail wheel shocks.



Jack



Jack Threadgill

1602 Brook Hollow Dr

Bryan, TX 77802

979-779-7155

threadgl@suddenlink.net

-----Original Message-----
From: fairchildclub@yahoogroups.com [mailto:fairchildclub@yahoogroups.com]
On Behalf Of ccmueller001
Sent: Tuesday, October 06, 2009 3:33 PM
To: fairchildclub@yahoogroups.com
Subject: [fairchildclub] bleeding expander tubes





Is it worth the effort to try to fill the Hayes brake expander tubes with
fluid, thereby expelling all the air in them, before installing the tubes?

I'm getting ready to get my PT-26s brakes back on and noted the stem for the
tubes is not near the top where air would tend to accumulate.

Also - I just reviewed the past couple years messages on the Hayes brakes
and the landing gear struts and have concluded that using DOT 5 in the brake
system and 5606 in the landing gear struts is a good way to go. Also using
something like TiteSeal, especially on the copper gaskets on the banjo
fittings, will reduce the likelihood of brake fluid leaks. Do these ideas
sound reasonable?

Is there something else I should know about before wading into this?

Charles





[Non-text portions of this message have been removed]'

'Charles,
For the what it's worth Dept.
I finished off my Hayes brake rebuild with DOT 3. It's an original glycol based brake fluid. DOT 3 and DOT 4 are the same thing. DOT 5 is silicon based. DOT 3 has all the inherit problems that everybody is aware of and should be flushed every couple of years which nobody does, including myself. Anyway, if you ever see that the color has changed from the original golden color to brown, it's time for a change. It's carrying moisture which invites corrosion. Silicon fluids are great for race cars and does have its place in the world because of its very high tolerance to boiling, but it does tend to aerate. So it's used in a closed systems. Regular brake systems are vented. I just think this tendency to aerate while it performs its work plus, the ascending and descending we all do could be troublesome. Vintage car owners who have used silicon fluids have reported a soft or spongy pedal as they drove over higher terrains. I'm a member of this group, take it for what it's worth. It was mentioned earlier someone filled their system from the bottom up, and that's a good way to go. A simple plastic disposable syringe available at Dairy supply stores works just fine. I've found the Hayes brakes very adequate for the airplane, but they must not drag at any time or they heat up and lock up. An interesting note , to this day no U.S.A manufacture of new vehicles uses silicon brake fluid. This is just a different point of view concerning brake fluids, many Fairchild owners swear by silicon.. Good luck!
Tom
Hanford,Ca.'