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My "fix" for dragging brakes

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pitts_pilot(at)bellsouth.
Guest

Posted: Tue Jul 19, 2011 12:26 pm Post subject: My "fix" for dragging brakes

Your spring idea is good.  However placing a compression spring over the 

cylinder shaft would be lighter and maybe more effective solution.

Linn



On 7/19/2011 3:53 PM, billz wrote:

 	  Quote: 	
		   



 I've been reading about the various dragging brake issues on the forum, talked with several folks and experienced the problem with a friend's RV-10.



 1. I found out, from the folks at Matco, that it is critical for the master cylinder to fully extend when pressure is removed from the brake pedals.  The last 1/16th in. of piston extension is needed for fluid to bypass internally allowing the brake pads to retract.  It doesn't take much to keep pressure on the brake pads.  My friend fixed his with a spring arrangement on the pedals.



 2. I also learned that minimizing friction in the brake pedals is important.  They should move freely with no binding.  All bolt holes should be properly drilled to assure free movement.  The bolts should not be overly tightened, to minimize drag.



 3. The Van's design uses two short AN3 bolts on each side of the bottom of the pedals.  This can result in some minor twisting that can add resistance to the pedal movement.  Matco suggested replacing these with one long bolt.  (I purchased AN3-60 bolts, $10 each)  I also used some aluminum tubing over the bolt to provide a spacer inside the pedal flanges.  I found springs at McMaster (part # 9271K542 and 9271K542, 270 deg, left and right hand).  These were put over the through bolt and aluminum tube.  The springs I settled on (to get enough return force) were larger inside diameter than the aluminum tube so I found some old garden hose to put over the tubing as a spacer.



 As you can see from the pictures, the springs provide return force and work nicely to provide positive pressure on the pedal and master cylinders.  So far, it seems like a "no drag" configuration.  Since I'm not flying, a final report will have to wait for the future.  Does all this make sense from what others have learned from experience??





 Read this topic online here:



 http://forums.matronics.com/viewtopic.php?p=347079#347079





 Attachments:



 http://forums.matronics.com//files/img_1388_336.jpg

 http://forums.matronics.com//files/img_1387_104.jpg

 http://forums.matronics.com//files/img_1386_109.jpg

msausen

Joined: 25 Oct 2007
Posts: 559
Location: Appleton, WI USA

Posted: Tue Jul 19, 2011 1:08 pm Post subject: My "fix" for dragging brakes

I forgot who did that but I've seen it before and it is what I plan to do.



Michael



--

billz

Joined: 08 Jul 2009
Posts: 26
Location: Clinton, New York

Posted: Tue Jul 19, 2011 1:22 pm Post subject: Re: My

I tried a variety of compression springs with collars, as previously shown on the forum.  I kept having problems with the spring only having a limited range of compression which limited the travel of the piston.  I could only get about 1 in compression before the spring was fully compressed.  Matco says all you need is 3/4 in travel, but I wanted to keep the option for greater travel, if needed.



Maybe someone else will have better luck with that approach than I did.



Good Luck!

pitts_pilot(at)bellsouth.
Guest

Posted: Tue Jul 19, 2011 2:11 pm Post subject: My "fix" for dragging brakes

I replied to Ralph off-line, but just a reminder ......



Slight brake dragging is a natural function of disc brakes.  The area

just outside the O-ring collects dirt which doesn't allow the puck to

retract more, and that O-ring gets stiff with time/heat.

The spring remedy only allows the cylinder shaft to extend fully

allowing the fluid pressure to relax.  Nothing is available to 'suck'

the brake puck back.

Linn

On 7/19/2011 5:22 PM, billz wrote:

 	  Quote: 	
		   



 I tried a variety of compression springs with collars, as previously shown on the forum.  I kept having problems with the spring only having a limited range of compression which limited the travel of the piston.  I could only get about 1 in compression before the spring was fully compressed.  Matco says all you need is 3/4 in travel, but I wanted to keep the option for greater travel, if needed.



 Maybe someone else will have better luck with that approach than I did.



 Good Luck!





 Read this topic online here:



 http://forums.matronics.com/viewtopic.php?p=347095#347095

philperry9(at)gmail.com
Guest

Posted: Tue Jul 19, 2011 3:26 pm Post subject: My "fix" for dragging brakes

It was me.  I'll see if I can find some old write ups and photos of the mod.  It was easy, cheap, and effective.  If I were building another one, I'd do the same thing again.



Phil



On Jul 19, 2011, at 4:05 PM, "RV Builder (Michael Sausen)" <rvbuilder(at)sausen.net> wrote:



[quote] 

 

 I forgot who did that but I've seen it before and it is what I plan to do.

 

 Michael

 

 --

Tim Olson

Joined: 25 Jan 2007
Posts: 2872

Posted: Tue Jul 19, 2011 7:38 pm Post subject: My "fix" for dragging brakes

While I'm not going to say you shouldn't improve it if

you want to, I will make a couple of comments:



1) We need to make sure that builders understand NOT

to torque the bolts too tight that the pedals hinge on.

If you don't torque them too tight, you're unlikely

to have an issue with them even with the standard bolts.

Improving them isn't going to hurt, but I would say

that it isn't necessary for most people...maybe those

with some parts or things that aren't in normal

tolerances.



2) Regarding the springs, that's the same deal. I don't

think most people will need anything like that.  Sure,

it may not hurt, but if you're going to do it, just do

it in a way that doesn't have any other possible failure

mode that could jam the brakes.  As long as you

do that, modify them if you think you need to. I just

don't think most people will need to.



3) As was already noted, disc brakes just work with a

bit of drag on them because there is no "retract"

spring for the pistons.  You push the brakes, they

go out and touch the discs, and when you release

the brakes they still just barely touch the discs.

Even a standard design for the pedals should not

cause any additional drag, as long as your pedals

retract and you keep your heels on the floor and

don't ride the brakes.  So again, while improving

them to your satisfaction isn't a bad thing, It's really

not a necessary thing. You're never going to eliminate

the inherent disc brake drag.



With 750+ hours on mine, and using the standard

setup, I've never seen any reason to have anything

more.  The one-piece bolt isn't a bad idea at all,

and if they included it all in the kit, I'd be

happy with it. But don't make all the other builders

think there is some problem with the design, because

those pedals will work just fine per-plans, provided

you don't overtorque or have some other misalignment

that causes the pedals to not move freely. All

builders should make sure that THIS isn't a problem

as they build...then they'll end up with a fine

working system.



Tim Olson - RV-10 N104CD



On 7/19/2011 2:53 PM, billz wrote:

 	  Quote: 	
		   



 I've been reading about the various dragging brake issues on the

 forum, talked with several folks and experienced the problem with a

 friend's RV-10.



 1. I found out, from the folks at Matco, that it is critical for the

 master cylinder to fully extend when pressure is removed from the

 brake pedals.  The last 1/16th in. of piston extension is needed for

 fluid to bypass internally allowing the brake pads to retract.  It

 doesn't take much to keep pressure on the brake pads.  My friend

 fixed his with a spring arrangement on the pedals.



 2. I also learned that minimizing friction in the brake pedals is

 important.  They should move freely with no binding.  All bolt holes

 should be properly drilled to assure free movement.  The bolts should

 not be overly tightened, to minimize drag.



 3. The Van's design uses two short AN3 bolts on each side of the

 bottom of the pedals.  This can result in some minor twisting that

 can add resistance to the pedal movement.  Matco suggested replacing

 these with one long bolt.  (I purchased AN3-60 bolts, $10 each)  I

 also used some aluminum tubing over the bolt to provide a spacer

 inside the pedal flanges.  I found springs at McMaster (part #

 9271K542 and 9271K542, 270 deg, left and right hand).  These were put

 over the through bolt and aluminum tube.  The springs I settled on

 (to get enough return force) were larger inside diameter than the

 aluminum tube so I found some old garden hose to put over the tubing

 as a spacer.



 As you can see from the pictures, the springs provide return force

 and work nicely to provide positive pressure on the pedal and master

 cylinders.  So far, it seems like a "no drag" configuration.  Since

 I'm not flying, a final report will have to wait for the future.

 Does all this make sense from what others have learned from

 experience??





 Read this topic online here:



 http://forums.matronics.com/viewtopic.php?p=347079#347079





 Attachments:



 http://forums.matronics.com//files/img_1388_336.jpg

 http://forums.matronics.com//files/img_1387_104.jpg

 http://forums.matronics.com//files/img_1386_109.jpg

ricksked(at)cox.net
Guest

Posted: Tue Jul 19, 2011 8:04 pm Post subject: My "fix" for dragging brakes

I didn't know there was a problem. But I only had 120 hours on mine before it went to it's new owner. I think I'll keep the original on the next one as well. IMHO it's feet that are dragging or riding on the pedals, not the system or design. But I don't piss in buckets either.



Rick Sked

Fuselage number 2 kit 1154 

Do not archive



Sent from my iPhone



On Jul 19, 2011, at 8:33 PM, Tim Olson <Tim(at)myrv10.com> wrote:



 	  Quote: 	
		   

 

 While I'm not going to say you shouldn't improve it if

 you want to, I will make a couple of comments:

 

 1) We need to make sure that builders understand NOT

 to torque the bolts too tight that the pedals hinge on.

 If you don't torque them too tight, you're unlikely

 to have an issue with them even with the standard bolts.

 Improving them isn't going to hurt, but I would say

 that it isn't necessary for most people...maybe those

 with some parts or things that aren't in normal

 tolerances.

 

 2) Regarding the springs, that's the same deal. I don't

 think most people will need anything like that.  Sure,

 it may not hurt, but if you're going to do it, just do

 it in a way that doesn't have any other possible failure

 mode that could jam the brakes.  As long as you

 do that, modify them if you think you need to. I just

 don't think most people will need to.

 

 3) As was already noted, disc brakes just work with a

 bit of drag on them because there is no "retract"

 spring for the pistons.  You push the brakes, they

 go out and touch the discs, and when you release

 the brakes they still just barely touch the discs.

 Even a standard design for the pedals should not

 cause any additional drag, as long as your pedals

 retract and you keep your heels on the floor and

 don't ride the brakes.  So again, while improving

 them to your satisfaction isn't a bad thing, It's really

 not a necessary thing. You're never going to eliminate

 the inherent disc brake drag.

 

 With 750+ hours on mine, and using the standard

 setup, I've never seen any reason to have anything

 more.  The one-piece bolt isn't a bad idea at all,

 and if they included it all in the kit, I'd be

 happy with it. But don't make all the other builders

 think there is some problem with the design, because

 those pedals will work just fine per-plans, provided

 you don't overtorque or have some other misalignment

 that causes the pedals to not move freely. All

 builders should make sure that THIS isn't a problem

 as they build...then they'll end up with a fine

 working system.

 

 Tim Olson - RV-10 N104CD

 

 

 

 On 7/19/2011 2:53 PM, billz wrote:

> 

> 

> I've been reading about the various dragging brake issues on the

> forum, talked with several folks and experienced the problem with a

> friend's RV-10.

> 

> 1. I found out, from the folks at Matco, that it is critical for the

> master cylinder to fully extend when pressure is removed from the

> brake pedals.  The last 1/16th in. of piston extension is needed for

> fluid to bypass internally allowing the brake pads to retract.  It

> doesn't take much to keep pressure on the brake pads.  My friend

> fixed his with a spring arrangement on the pedals.

> 

> 2. I also learned that minimizing friction in the brake pedals is

> important.  They should move freely with no binding.  All bolt holes

> should be properly drilled to assure free movement.  The bolts should

> not be overly tightened, to minimize drag.

> 

> 3. The Van's design uses two short AN3 bolts on each side of the

> bottom of the pedals.  This can result in some minor twisting that

> can add resistance to the pedal movement.  Matco suggested replacing

> these with one long bolt.  (I purchased AN3-60 bolts, $10 each)  I

> also used some aluminum tubing over the bolt to provide a spacer

> inside the pedal flanges.  I found springs at McMaster (part #

> 9271K542 and 9271K542, 270 deg, left and right hand).  These were put

> over the through bolt and aluminum tube.  The springs I settled on

> (to get enough return force) were larger inside diameter than the

> aluminum tube so I found some old garden hose to put over the tubing

> as a spacer.

> 

> As you can see from the pictures, the springs provide return force

> and work nicely to provide positive pressure on the pedal and master

> cylinders.  So far, it seems like a "no drag" configuration.  Since

> I'm not flying, a final report will have to wait for the future.

> Does all this make sense from what others have learned from

> experience??

> 

> 

> 

> 

> Read this topic online here:

> 

> http://forums.matronics.com/viewtopic.php?p=347079#347079

> 

> 

> 

> 

> Attachments:

> 

> http://forums.matronics.com//files/img_1388_336.jpg

> http://forums.matronics.com//files/img_1387_104.jpg

> http://forums.matronics.com//files/img_1386_109.jpg

> 

> 

> 

> 

> 

> 

>

dave.saylor.aircrafters(a
Guest

Posted: Tue Jul 19, 2011 8:09 pm Post subject: My "fix" for dragging brakes

What Tim said.



Plus, keep in mind that the master cylinders have internal springs

that push the piston back out.  If they aren't sufficient there could

be another problem.  The clothes pin springs and long bolts are a nice

touch but I see a couple of wear points that might need to eventually

be addressed.  Fewer parts are usually better!



Make sure the assembly is free, even a little sloppy, and it should work fine.



Dave Saylor  895 hours

AirCrafters

140 Aviation Way

Watsonville, CA 95076

831-722-9141 Shop

831-750-0284 Cell



On Tue, Jul 19, 2011 at 8:33 PM, Tim Olson <Tim(at)myrv10.com> wrote:

 	  Quote: 	
		   



 While I'm not going to say you shouldn't improve it if

 you want to, I will make a couple of comments:



 1) We need to make sure that builders understand NOT

 to torque the bolts too tight that the pedals hinge on.

 If you don't torque them too tight, you're unlikely

 to have an issue with them even with the standard bolts.

 Improving them isn't going to hurt, but I would say

 that it isn't necessary for most people...maybe those

 with some parts or things that aren't in normal

 tolerances.



 2) Regarding the springs, that's the same deal. I don't

 think most people will need anything like that. Â Sure,

 it may not hurt, but if you're going to do it, just do

 it in a way that doesn't have any other possible failure

 mode that could jam the brakes. Â As long as you

 do that, modify them if you think you need to. I just

 don't think most people will need to.



 3) As was already noted, disc brakes just work with a

 bit of drag on them because there is no "retract"

 spring for the pistons. Â You push the brakes, they

 go out and touch the discs, and when you release

 the brakes they still just barely touch the discs.

 Even a standard design for the pedals should not

 cause any additional drag, as long as your pedals

 retract and you keep your heels on the floor and

 don't ride the brakes. Â So again, while improving

 them to your satisfaction isn't a bad thing, It's really

 not a necessary thing. You're never going to eliminate

 the inherent disc brake drag.



 With 750+ hours on mine, and using the standard

 setup, I've never seen any reason to have anything

 more. Â The one-piece bolt isn't a bad idea at all,

 and if they included it all in the kit, I'd be

 happy with it. But don't make all the other builders

 think there is some problem with the design, because

 those pedals will work just fine per-plans, provided

 you don't overtorque or have some other misalignment

 that causes the pedals to not move freely. All

 builders should make sure that THIS isn't a problem

 as they build...then they'll end up with a fine

 working system.



 Tim Olson - RV-10 N104CD



 On 7/19/2011 2:53 PM, billz wrote:

>

> 

>

> I've been reading about the various dragging brake issues on the

> forum, talked with several folks and experienced the problem with a

> friend's RV-10.

>

> 1. I found out, from the folks at Matco, that it is critical for the

> master cylinder to fully extend when pressure is removed from the

> brake pedals. Â The last 1/16th in. of piston extension is needed for

> fluid to bypass internally allowing the brake pads to retract. Â It

> doesn't take much to keep pressure on the brake pads. Â My friend

> fixed his with a spring arrangement on the pedals.

>

> 2. I also learned that minimizing friction in the brake pedals is

> important. Â They should move freely with no binding. Â All bolt holes

> should be properly drilled to assure free movement. Â The bolts should

> not be overly tightened, to minimize drag.

>

> 3. The Van's design uses two short AN3 bolts on each side of the

> bottom of the pedals. Â This can result in some minor twisting that

> can add resistance to the pedal movement. Â Matco suggested replacing

> these with one long bolt. Â (I purchased AN3-60 bolts, $10 each) Â I

> also used some aluminum tubing over the bolt to provide a spacer

> inside the pedal flanges. Â I found springs at McMaster (part #

> 9271K542 and 9271K542, 270 deg, left and right hand). Â These were put

> over the through bolt and aluminum tube. Â The springs I settled on

> (to get enough return force) were larger inside diameter than the

> aluminum tube so I found some old garden hose to put over the tubing

> as a spacer.

>

> As you can see from the pictures, the springs provide return force

> and work nicely to provide positive pressure on the pedal and master

> cylinders. Â So far, it seems like a "no drag" configuration. Â Since

> I'm not flying, a final report will have to wait for the future.

> Does all this make sense from what others have learned from

> experience??

>

>

> Read this topic online here:

>

> http://forums.matronics.com/viewtopic.php?p=347079#347079

>

>

> Attachments:

>

> http://forums.matronics.com//files/img_1388_336.jpg

> http://forums.matronics.com//files/img_1387_104.jpg

> http://forums.matronics.com//files/img_1386_109.jpg

>

Dick Sipp

Joined: 11 Jan 2006
Posts: 215
Location: Hope, MI

Posted: Tue Jul 19, 2011 8:43 pm Post subject: My "fix" for dragging brakes

We'll have to "ditto" Tim's comments on this issue.  We got almost 300 hours 

on the first set of pads with a standard per the plans brake installation.



The earlier RV's all had similar issues.  In my opinion most of these are 

related to the somewhat severe angle that the pedals meet your feet, i.e. it 

is very easy to apply brake pressure when you would think you are not. 

 The -10, IMHO, is the least problematic in this regard so far.  (The RV-12 

kit includes plastic blocks installed on the bottom of the pedals to reduce 

this angle not unlike what others have done as a mod on the 10)



I believe a little practice in the technique of keeping heels on the floor 

at all times unless brake application is desired will go a long way to 

getting good brake pad life and minimal heating.



Tailwinds,



Dick Sipp

RV-4, RV-10, B-25D

all castering nose wheels and sensitive brakes

Dick Sipp

Joined: 11 Jan 2006
Posts: 215
Location: Hope, MI

Posted: Tue Jul 19, 2011 8:46 pm Post subject: My "fix" for dragging brakes

CORRECTION:



My bad, of course the RV-4 does not have a castering nose wheel.



Dick



--

philperry9(at)gmail.com
Guest

Posted: Thu Jul 21, 2011 8:24 am Post subject: My "fix" for dragging brakes

A day or two late, but here are some details on the mod.  I shot a video on my brake lines and someone noticed the return springs.  At the bottom of this thread is a narrative description.

http://www.vansairforce.com/community/showthread.php?t=63149

The single best thing one could do is bend the flanges of the pedals inward so the bolt holes are perfectly aligned.  This eliminates all binding caused by misaligned boles on both sides of the pedal.  Once they're aligned there is absolutely no binding and the pedal is free to do anything it wants.  I don't think I even need the return springs now, but since they are there and I already spent the money on them - I left them.

Phil

On Tue, Jul 19, 2011 at 6:22 PM, Phil Perry <philperry9(at)gmail.com (philperry9(at)gmail.com)> wrote:

[quote] It was me.  I'll see if I can find some old write ups and photos of the mod.  It was easy, cheap, and effective.  If I were building another one, I'd do the same thing again.

 Phil

 On Jul 19, 2011, at 4:05 PM, "RV Builder (Michael Sausen)" <rvbuilder(at)sausen.net (rvbuilder(at)sausen.net)> wrote:

 > --> RV10-List message posted by: "RV Builder (Michael Sausen)" <rvbuilder(at)sausen.net (rvbuilder(at)sausen.net)>

 >

 > I forgot who did that but I've seen it before and it is what I plan to do.

 >

 > Michael

 >

 > --

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