X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Fri, 11 Jan 2013 19:03:16 -0500 Message-ID: X-Original-Return-Path: Received: from nm7.access.bullet.mail.mud.yahoo.com ([66.94.237.208] verified) by logan.com (CommuniGate Pro SMTP 6.0.1) with ESMTPS id 6007342 for lml@lancaironline.net; Fri, 11 Jan 2013 17:55:16 -0500 Received-SPF: neutral receiver=logan.com; client-ip=66.94.237.208; envelope-from=ralphlove@stanfordalumni.org Received: from [66.94.237.192] by nm7.access.bullet.mail.mud.yahoo.com with NNFMP; 11 Jan 2013 22:54:41 -0000 Received: from [68.142.198.107] by tm3.access.bullet.mail.mud.yahoo.com with NNFMP; 11 Jan 2013 22:54:41 -0000 Received: from [127.0.0.1] by smtp112.sbc.mail.mud.yahoo.com with NNFMP; 11 Jan 2013 22:54:41 -0000 X-Yahoo-Newman-Id: 825858.34188.bm@smtp112.sbc.mail.mud.yahoo.com X-Yahoo-Newman-Property: ymail-3 X-YMail-OSG: xKuG9TQVM1ltP.7tdgpDwXjN3NC.ehOD58KSHyZmvaR58aw drWkFetw9OaNeJSC2VidUqOX.bNCIJjGMVQhi5yrmSg4QkBuaYnKBplkBpxL Cu_C9dJeWEaZXRx71gWhIsKNk98v_3AUJSlHNY.n1teDqWSr.OKXP1zkqwwE b8_Augl_kz8fsqTt.itB9Jx0FOOBATE59FI1JUmTkUZqlC.mx16JUF35BRNv UsUGoaJBfG7_4XR__4Vi.K9BNshburUG.h9xMC1zWU.q_QLi_vBVupYmQjNr 2kSsLnhRy3x_rypAPVLEKvlLQJPZ7.arByonzWVHTFrQ9R0WVsXdAZXuJsp5 b1r1i6kVRVwEfvK.5pZZV1_wxxCR7rdtx9hjc1etQgpwd9IUeEfZkQ5n2p4A erPzr4gdvW3ATDHoGDqSbFMGXjsCb8659O9aZfRzSxjLpUqfqRd.VUyId8rd FB4zqKFj6TIB1vFlfc188SC90e3Am3ECZ4Usn1rf9H_xmu2tAsQhQVwNFS8I GrusM3GoKPm_ij3YYrcj8yzP1UJC9Vvg1h_pBth8Q0gLdD9E6Va7ibjx8_zQ q X-Yahoo-SMTP: O0s9NnaswBCimploNHufwcJQi58B5NjMy.C2WAjfZjgmjJOd Received: from [10.0.1.5] (ralphlove@67.188.62.229 with plain) by smtp112.sbc.mail.mud.yahoo.com with SMTP; 11 Jan 2013 14:54:41 -0800 PST Subject: Fwd: [LML] Re: bleeding brakes References: From: Ralph Love Content-Type: multipart/alternative; boundary=Apple-Mail-BC7F76BD-5DD6-43D7-90EE-82677D7ED584 X-Mailer: iPad Mail (10A523) X-Original-Message-Id: <99258641-2D1B-4C42-8753-340D19EC8426@stanfordalumni.org> X-Original-Date: Fri, 11 Jan 2013 14:54:41 -0800 X-Original-To: Lancair Mailing List Content-Transfer-Encoding: 7bit Mime-Version: 1.0 (1.0) --Apple-Mail-BC7F76BD-5DD6-43D7-90EE-82677D7ED584 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Begin forwarded message: > From: "Robert Engholm" > Date: January 11, 2013, 1:12:40 PM PST > To: "Ralph Love" > Subject: Re: [LML] Re: bleeding brakes >=20 > I have never heard of pulling a pure vacuum on the master cylinder and rel= easing fluid that will fill all wheel cylinders > properly. See all the methods listed on wikipedia. > =20 > http://en.wikipedia.org/wiki/Brake_bleeding > =20 > Robert > =20 > ----- Original Message ----- > From: Ralph Love > To: Robert Engholm > Sent: Friday, January 11, 2013 12:12 PM > Subject: Fwd: [LML] Re: bleeding brakes >=20 > Comments from LML >=20 >=20 > Begin forwarded message: >=20 >> From: Gary Casey >> Date: January 10, 2013, 9:01:23 AM PST >> To: lml@lancaironline.net >> Subject: [LML] Re: bleeding brakes >> Reply-To: "Lancair Mailing List" >> Regarding the bleeding of brakes, the standard method of filling brake sy= stems at automotive factories is to leave all connections tight and pull a v= acuum at the reservoir. Then a measured quantity is added to the reservoir,= the vacuum released and that's it. One problem with our systems is that th= e hoses and lines are larger than they need to be, allowing air bubbles to s= tay in place and not be "dragged along" with the fluid. I think the best ap= proach is to pull a vacuum at the reservoir. It won't "pull debris" from th= e wheel cylinder, as the fluid there stays put. The bubble enlarges and tha= t gives it the impetus to rise to the reservoir. Or, as Robert says, a pres= sure bleed can push the fluid fast enough to drag the air with it. Except I= would probably pressurize the wheel cylinder to at least push the air uphil= l. Either way works, though. >> Gary Casey >> =20 >>=20 >> =20 >>> Reverse bleeding pushes all the debris from the wheel cylinder up into t= he master cylinder. This will be trouble in the future.. >>> The two person method works well but you must not wait long between the p= umping action at the master cylinder as any bubble >>> in a hose will travel beyond the prior pumping action rendering the blee= d useless. >>> The best is the pressure bleed. A small pot is filled with brake fluid a= nd pressurized to 20 psi. The pot is connected to the >>> master cylinder reservoir. When the bleeder valve is opened at the wheel= cylinder, the fluid is pushed out at a fast rate allowing >>> all debris and air to escape. This is the de-facto standard in the auto i= ndustry and commercial aircraft. >>> Robert --Apple-Mail-BC7F76BD-5DD6-43D7-90EE-82677D7ED584 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: 7bit



Begin forwarded message:

From: "Robert Engholm" <REngholm@interphasic.com>
Date: January 11, 2013, 1:12:40 PM PST
To: "Ralph Love" <ralphlove@stanfordalumni.org>
Subject: Re: [LML] Re: bleeding brakes

I have never heard of pulling a pure vacuum on the master cylinder and releasing fluid that will fill all wheel cylinders
properly. See all the methods listed on wikipedia.
 
 
Robert
 
----- Original Message -----
From: Ralph Love
Sent: Friday, January 11, 2013 12:12 PM
Subject: Fwd: [LML] Re: bleeding brakes

Comments from LML


Begin forwarded message:

From: Gary Casey <casey.gary@yahoo.com>
Date: January 10, 2013, 9:01:23 AM PST
To: lml@lancaironline.net
Subject: [LML] Re: bleeding brakes
Reply-To: "Lancair Mailing List" <lml@lancaironline.net>

Regarding the bleeding of brakes, the standard method of filling brake systems at automotive factories is to leave all connections tight and pull a vacuum at the reservoir.  Then a measured quantity is added to the reservoir, the vacuum released and that's it.  One problem with our systems is that the hoses and lines are larger than they need to be, allowing air bubbles to stay in place and not be "dragged along" with the fluid.  I think the best approach is to pull a vacuum at the reservoir.  It won't "pull debris" from the wheel cylinder, as the fluid there stays put.  The bubble enlarges and that gives it the impetus to rise to the reservoir.  Or, as Robert says, a pressure bleed can push the fluid fast enough to drag the air with it.  Except I would probably pressurize the wheel cylinder to at least push the air uphill.  Either way works, though.
Gary Casey
 

 
Reverse bleeding pushes all the debris from the wheel cylinder up into the master cylinder. This will be trouble in the future..
The two person method works well but you must not wait long between the pumping action at the master cylinder as any bubble
in a hose will travel beyond the prior pumping action rendering the bleed useless.
The best is the pressure bleed. A small pot is filled with brake fluid and pressurized to 20 psi. The pot is connected to the
master cylinder reservoir. When the bleeder valve is opened at the wheel cylinder, the fluid is pushed out at a fast rate allowing
all debris and air to escape. This is the de-facto standard in the auto industry and commercial aircraft.
Robert
--Apple-Mail-BC7F76BD-5DD6-43D7-90EE-82677D7ED584--