X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [24.25.9.102] (HELO ms-smtp-03-eri0.southeast.rr.com) by logan.com (CommuniGate Pro SMTP 4.3.5) with ESMTP id 1020601 for flyrotary@lancaironline.net; Fri, 24 Jun 2005 15:22:13 -0400 Received-SPF: pass receiver=logan.com; client-ip=24.25.9.102; envelope-from=eanderson@carolina.rr.com Received: from edward2 (cpe-065-188-083-049.carolina.res.rr.com [65.188.83.49]) by ms-smtp-03-eri0.southeast.rr.com (8.12.10/8.12.7) with SMTP id j5OJLPY5019899 for ; Fri, 24 Jun 2005 15:21:26 -0400 (EDT) Message-ID: <004801c578f1$eb3f8ff0$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Engine Rebuild - Coolant Leak Cause Date: Fri, 24 Jun 2005 15:21:26 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0045_01C578D0.63A14050" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2180 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_0045_01C578D0.63A14050 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Thanks, Lynn for the brake tips. =20 I'll make it a point to change the "O" ring when I change the brake = pads. Yes, I have noticed the difference in pad wear, but could never = figure out why. =20 Ed The single piston slider type calipers rely to some extent on rotor = runout to help knock back the pads, once pressure has been released.=20 In aircraft applications this does not work worth a damn because the = wheels are so light and are turned over so little. Also the slider = mechanism has so much friction that the non piston pad almost always = wears faster than the piston end pad. A plane used often has little = difference in pad wear. Also when applying pressure the "O" ring seal = will deform slightly as it is pushed along with the moving piston. When pressure is released, the deformed "O" ring returns to normal and = retracts the piston. This may not move the slider end of the caliper at all. If there is = some runout in the rotor, the rotor will knock back the slider end pad = slightly. Even side loading the wheel will deform the assembly enough to = knock the pads back.=20 If there is no flex line to connect the caliper to the fixed brake = line, then the aluminum brake line must flex with each brake = application. Aluminum has a very short fatigue life. The tighter the = bend radius, the lower the pressure rating, and the shorter the fatigue = life. A racing tip. Fresh "O" rings keep the brake drag down.=20 Lynn E. Hanover ------=_NextPart_000_0045_01C578D0.63A14050 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
 
 Thanks, Lynn for the brake tips. =20
 
I'll make it a point to change the "O" ring when I change the = brake=20 pads.  Yes, I have noticed the difference in pad wear, but could = never=20 figure out why. 
 
Ed
 
 
The single piston slider type calipers rely to some extent on = rotor=20 runout to help knock back the pads, once pressure has been=20 released. 
 
In aircraft applications this does not work worth a damn because = the=20 wheels are so light and are turned over so little. Also the slider = mechanism=20 has so much friction that the non piston pad almost always wears = faster=20 than the piston end pad. A plane used often has little difference in = pad wear.=20 Also when applying pressure the "O" ring seal will deform slightly as = it is=20 pushed along with the moving piston.
When pressure is released, the deformed "O" ring returns to = normal and=20 retracts the piston.
 
This may not move the slider end of the caliper at all. If there = is some=20 runout in the rotor, the rotor will knock back the slider end pad = slightly.=20 Even side loading the wheel will deform the assembly enough to knock = the pads=20 back.
 
If there is no flex line to connect the caliper to the fixed = brake line,=20 then the aluminum brake line must flex with each brake application. = Aluminum=20 has a very short fatigue life. The tighter the bend radius, the lower = the=20 pressure rating, and the shorter the fatigue life.
A racing tip. Fresh "O" rings keep the brake drag down.
 
 
Lynn E. Hanover 
------=_NextPart_000_0045_01C578D0.63A14050--