Brake failure at end of taxiing !

Abstract:    Last flight of a Young Eagles day, taxiing to fuel pump and brakes (spoiler lever went all the way to the stop) Brake fluid
noticeable on left main.

Subject: Brake failure at end of taxiing !
From: "cloudsipper" amelendy@yahoo.com
Date: 9/27/08 1:26 PM
To: Taifun17E@yahoogroups.com

Last flight of a Young Eagles day, taxiing to fuel pump and brakes (spoiler lever went all the way to the stop) Brake fluid
noticeable on left main. On a scale of 1 to 10 where 10 means get a ($$ A&P mechanic to fix it) how difficult is this going to be to repair? Is the brake system from Cleveland? any part numbers? I'm thinking an O-ring failure, but I guess it could be more serious... HELP !!

Fortunately it was the last flight of the day and the failure wasn't on the runway at high speed..

Subject: RE: [Taifun17E] Brake failure at end of taxiing !
From: "Fred Bonar" fbonar@yahoo.com
Date: 9/27/08 1:39 PM
To: Taifun17E@yahoogroups.com

# is on the brake cliper, should be Cleveland and parts available from Aircraft spruce, don’t know about cost but mine are due...

Subject: Re: Brake failure at end of taxiing !
From: "cloudsipper" amelendy@yahoo.com
Date: 9/27/08 3:30 PM
To: Taifun17E@yahoogroups.com

Yup.. looks like "30-9" a standard Cleveland assy. I'm leaning toward just ordering an O-ring.. any thoughts? The whole assy is ~$380 so it's not catastrophic.

I guess the tricky part is bleeding the assy after the fix .. everyone says to pump fluid up from the bleeder valve and watch for overflow at the master reservoir.. I think I can do that.. will try a turkey baster and some tubing. wish me luck.
Al

Subject: Re: [Taifun17E] Re: Brake failure at end of taxiing !
From: Bob Gurr gurrini@yahoo.com
Date: 9/28/08 11:15 AM
To: Taifun17E@yahoogroups.com

Use a small hand squeeze pump oil can with a small tip that you can inset securely into a piece of tubing since you will need to generate a bit of pressure against the bleed screw as you open it carefully and close off at the end of each squeeze. Be sure to add something to stop the open master cylinder from letting fluid squirt up into the cockpit.

Bob N11VR

Subject: Brake dis-assembly & pad replacement
From:"cloudsipper" <amelendy@Iyahoo.com>
Date: 9/29/08 9:49 AM
To: Taifun17E@yahoogroups.com

Caliper assy removal was pretty easy, the o-ring shows some wear/roughness maybe even some deterioration (heat?), the
cross-section is almost square! Some corrosion outboard of the o-ring, cleaned up OK with scotchbrite. O-rings are $0.39 at Aircraft Spruce, but most FBO's seem to carry a few. The oil pump dispenser seems like the common way to push fluid up into the reservoir. The reservoir is under a removable panel under the baggage section upholstery. So far, so good.. I went ahead and replaced brake pads since I had the unit apart (besides, the pads were oil soaked). The only uncertainty now is the "burning -in" of the new pads. (I guess if the pads don't glaze up well, I'll be doing circles on run-up.) I believe all of this can be done by an owner, even if the ship is
certified. Correct me if I'm wrong.

Subject: Re: [Taifun17E] Brake dis-assembly & pad replacement
From: Bob Gurr gurrini@yahoo.com
Date: 9/29/08 10:56 AM
To: Taifun17E@yahoogroups.com

Glazing? Just use maximum braking on landings so you generate some real heat.

N11VR

Subject: RE: [Taifun17E] Re: Brake failure at end of taxiing !
From: "Fred Bonar" fbonar@yahoo.com
Date: 9/29/08 7:48 AM
To: Taifun17E@yahoogroups.com

Al

Mine are coming up, pads are 80% but since its only been flown 15 hours in 9 years, all seals are suspect, the 105 to 110 heat didn’t help either. Already replaced the compass and fuel seals and rings.

Bob had some great tips on bleeding….

Fred

Subject: AW: [Taifun17E] Brake dis-assembly & pad replacement
From: "KORFF LUFTFAHRT DB" cornelia.korff@yahoo.com
Date: 9/30/08 1:02 AM
To: Taifun17E@yahoogroups.com

Dear Fred,

Please be informed that the gaskets/o-rings in the master brake cylinder MAGURA are not for use with Fluid 41 (former Fluid 4)! It needs DOT 3 or 4. With Fluid 41 it will be damaged!

The o-rings you can buy from Spruce for the calliper are normally for the use with Fluid 41 and will not be stable with DOT 3 or 4 and will dissolve after a short time.

You need o-rings for DOT 3 or 4 maybe from TOST.

www.tost.de

Part-No.: 075835 O-ring for 30-9, for brake fluid DOT 4

Best Regards,

Cornelia Korff

(Technischer Leiter)

KORFF LUFTFAHRT

RAINER KORFF

Flugplatz Mainbullau 7

63897 Miltenberg

Werftbetrieb Flugplatz Mainbullau:

Tel. : +49 9371 99145

Fax: +49 9371 95 94 06

Hotline: +49 172 92 13 279

+49 172 38 79 530

Büro / Office Dietzenbach:

Tel.: +49 6074 4006 33

Fax: +49 6074 4006 46

Subject: Re: [Taifun17E] Brake dis-assembly & pad replacement
From:Thomas Driscoll tomsinegypt@yahoo.com
Date: 9/30/08 1:31 AM
To: Taifun17E@yahoogroups.com

Greetings Cloudsipper,

I'm not here to correct you but guide you to the language that may answer your question. Whether you are authorized or not to perform work on a certificated aircraft falls under FAR 43.3 (g) and (h). Pilots are allowed to do preventive maintenance on their own aircraft. The question does arise as to what exactly defines "preventive maintenance." As an example, I worked on a Cessna 182 where the pilot replaced the Plexiglas windshield. The pilot felt that this fell under the preventive maintenance rule, however, he was unable to satisfactorily answer the question "where and who trained you to do this replacement?" If you can't answer that, then possibly its not preventive maintenance.

Tom Driscoll

Subject: Re: [Taifun17E] Brake dis-assembly & pad replacement
From: Allan Melendy amelendy@yahoo.com
Date: 9/30/08 6:50 AM
To: Taifun17E@yahoogroups.com

Excellent point, Tom, and no offense taken. I reviewed part 43, and I believe that for certified aircraft, the repair I effected is probably *not* authorized.
The good news:
My type 2 Taifun, is not certified in this country, the aircraft was issued an Experimental airworthiness and Part 43 does not apply.

The bad news:
My type 2 is also not "owner-built" so the annual "condition inspection" must be done by a licensed A&P..etc. (emphasis mine)

The EAA has done a lot of work to support experimental builders and in one instance addresses who can perform a Condition Inspection by explaining that the inspection can be performed by any licensed A&P mechanic, an FAA Approved Repair Station, or by the builder of the airplane provided the builder obtains a “Repairmanʼs Certificate” from the FAA. They note, however, that unlike an annual for a type certificated aircraft, the A&P mechanic does NOT have to have his/her “Inspection Authorization.”.
The reason I expounded is that many of the Taifuns have experimental airworthiness certificates, and their owners would find themselves in the same situation. There are some issues about avionics, specifically transponders, that make exceptions to these rules.
In the end, each person has to decide how best to handle his/her maintenance. Even for owners of certified airplanes, however there may be cost savings.. (after all why pay an A&P to remove cowlings, or change oil?).
Bests,
Al Melendy aka Cloudsipper