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Brake Pedal sticking issues

A

avi8tor50

Well Known Member
Started my rudder/brake peddle assembly. Have read about the locked brake issues and the proposed solutions. Was wondering just how frequent this problem occurs, how many builders are actually installing the springs on the Matco cylinders, and how many are using the AN3-60 bolt at the bottom of the brake peddles instead of the two separate bolts. Has Van ever commented on this problem? Seems like a service bulletin of some sort might be in order.
 
I went with the long bolts

I wasn't real happy with the way the pedals felt when operated. Then after reading the earlier post that suggested the long bolts I tried that.
What a world of difference that made!
Those two short bolts let everything wobble around too much to for me. And if you try and take the wobble out they will make the brake pedal stick.

While I had it apart I spent some extra time and filed down the side of the brake pedals to allow a thin washer to fit between the brake pedal and rudder pedal on each side. With a little "extra' room to spare. Now with the long bolt and the brake pedals able to float sideways just a touch they are really smooth. They pop right back when you let go of them. I don't have any fluid in them yet, but I think I'll be fine without the extra springs that were also mentioned.

Mark
 
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Ditto here

Dave Parson went this way on his -7A and I just assembled my rudder/brakes within the last week. From what I remember, I think I used a -54 bolt. The action on the pedals is really nice with good spring-back. This is another area where Van's ought to make a change.

P9300152.JPG
 
springs

I went the spring route and it worked out great. Hadn't seen the long bolt solution until after I had installed the springs. May try that some day, but since the springs work well for me, I'll just leave them alone for awhile. jack
 
Jim P said:
Dave Parson went this way on his -7A and I just assembled my rudder/brakes within the last week. From what I remember, I think I used a -54 bolt.
Click to expand...
Can anyone confirm Jim's guess of a size -54 bolt? I bet they're pretty expensive, so I'd prefer not to guess myself before I order from Spruce!
 
The 60's are a bit long but work good

The 60's are a bit too long. But I couldn't find the correct size easily.
I made a spacer (about 1/4" long) out of some of the 5/16" tubing stock.
It worked good, and you can't see it from the front anyway.

Mark

brakepedals1sfi4.jpg
 
Yep, they're expensive

I checked my on-line Aircraft Spruce account and they were -56 bolts at about $9.20 each. Ouch! On the other hand, it's cheap for ensuring the brakes are working nice and smooth.

Jim
 
I used -60 bolts.. a little long, but a few washers make it work. They were $5 each at Wicks.
 
Might want to look at flanged-sleeve Oilite bushings from McMaster-Carr, or similar. Have a bearing surface at these pivot points.
 
Surely there must be a less expensive bolt that can be used! I realize that safety is always primary, HOWEVER, do we really need to spend $30-$40 for four bolts??? (I have passenger brake pedals as well so I need 4). Has anyone found something less expensive?
 
If you use really long bolts don't you end up with the threaded area being in one of the pivot/bearing areas? I would think that a long clevis pin, either purchased, or made out of drill rod and cottered at each end, together with the previously mentioned flanged Oilite bushings would do nicely here.
 
Threaded area "ok"

Ron,
No, you don't end up with threads in the pivot area. The long bolts have the same length of threads as the short bolts. I didn't measure this, just going from memory.

I too thought about the drill rod and cotter pinning each end. The Oilite bushings are certainly a good idea also. The bushings would make it last a very long time for sure. After thinking about about it for too long I just bit the bullet and ordered the $$ long bolts.

I plan to put a drop of oil on the pivot points once a year, and I think they will last a very long time.

Mark
 
Longer bolts not necessarily the solution

OK... I just spent $18.00 to buy two AN-56 bolts to go through the pilot side rudder pedals hoping that would reduce the friction in the pedal. I have no doubt that the long bolts are probably better than 2 separate bolts, but in and of themselves are not really a solution to the main problem in my case.

Obviously, in order for the pedals to move easily there must be little or no friction when they rotate relative to the weldment. Either the pedal needs to rotate around the bolt freely or the bolts need to rotate inside the weldments freely. In my case, the main problem is that I reamed all the holes for 3/16 so it is a snug fit. Good practice in normal cases. However, since something needs to rotate around the bolt, either the pedal holes or the weldment holes need to be slightly larger than 3/16, say a #10 or #11. Logical?


Thanks.

Edit: After checking last night, I think one of the other problems that may be causing some people to have sticking brake pedals is tightening the castle nuts too tight. In this case, it seems like the castle nuts should be tightened just enough to hold everything together, but definitely not torqued to 25#. This should allow the pedal to rotate more freely and the cotter pin will do its job by holding the nut on. Does this seem right?

I did run a different (larger) 3/16 reamer through the brake pedals and that seemed to help with the hole friction that I mentioned above.
 
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This is what the long bolt buys you. With the two small bolts you have to tighten them quite a bit, otherwise they change angle and the pedal moves around at the pivot point. With the longer bolt, the angle stays the since it goes through both sides. Thus, you can make it looser and the pedal doesn't move around as much. Hard to explain, but it does help a bit.

You're right, though. It's not a complete solution. I'm still seeing one of my pedals not snap back sometimes. I bought some springs from McMaster that I'm going to try as well.
 
Thanks Dave. Your explanation makes sense, and I'm still planning to use the long bolts for those reasons. I'll be interested to hear how those springs work and would definitely be interested in knowing which ones you are using.

For those who are contemplating long bolts, I might recommend just going to Wicks and buying the AN3-60 bolts. Although they are longer than necessary, they are only $5 instead of $9 each for AN3-56 at Spruce. You can then just use extra washers or a spacer. I'll be doing this on my passenger side.
 
Sticking brake pedals

Here is one solution for sticking brake pedals. The bushings are flanged oilite, the rod is 3/16 drill rod and there is actually a very thin-walled aluminum tube over the drill rod between the bushings. The angle that's opposite the cylinder mount side is made from .125 for added bearing support. I will probably just use push-nuts to secure the rods in place. These pedals are smooth!

 
Sticking Brakes

My right brake was sticking and the fix was a return spring on the brake cylinder piston. It takes were little movement on the pistion to cause the brakes to stick. I disconnected different bolts trying to find something binding and every thing worked as the plans. I put the springs on and no brake problems since. My right brake pad wore out in 50 hours!

If you find the brakes sticking, pull back on the top of the brake pedal and see what happens, you will be supprised to see how little it takes to fix the problem!
 
What size spring, source

Just assembled my brakes for what I thought was the final time :eek: . Can anyone tell me the size and source for the return spring being discussed?
 
Brake Springs

The spring is a Hillman #181 (3 1/16" x 9/16" x .054) but others will work I'd imagine. I have the old brkes and they came with springs. I just added a 3/8 set screw collar to give it more tension.

My right side brakes don't have springs and I will be adding them soon.
 
Try your local ACE hardware

..that's where we got em when coming up with the fix for ours. They had the shaft collars and bushings too.
 
Alternative to long bolts

Instead of buying long bolts, I got a piece of 3/8" aluminum rod (tubing would be better but the aviation aisle at the hardware store didn't have any).
I cut the rod to just fit inside the rudder pedal with 1 AN washer on each side, then drilled and tapped for the pivot bolts. The long rod acts as the nuts, as well as keeping the bolts aligned. I also drilled holes for the cotter pins (an alternative would be to use bolts with drilled heads and safety wire them to the rudder flange they go through).
It's a bit more work than long bolts, but a lot cheaper.
 
Brake pedal still sticking after long (56) bolts

When I was assembling the toe brakes during the building process, I used the long bolts as suggested here. However, after I started flying, I found that my left brake was still dragging. :( The right brake was OK. I first tried some lubrication to see if that would correct the problem. No joy! So today, I added a compression springs on top of the master cylinder. This seems to have fixed the problem but I still have not flown since the installation.:)
 
The full effect.

I have been reading about this for a while.

We stock and sell the AN3-56 bolts.

They are due in late April, we had to order a manufacturer run after the last promo.

Using these the rudder pedals are not likely to stick at the pivot point.

The master cylinders may still have an issue and need springs.

When it comes to my brakes I will be doing both.

This is not an area to compromise.:rolleyes:

see

http://www.vansairforce.com/community/showthread.php?t=11598

http://www.vansairforce.com/community/showthread.php?t=24049

http://www.vansairforce.com/community/showthread.php?t=15246

If you need some we have them. We have sold over 150 of these in the last 6 months.

http://www.gen-aircraft-hardware.com/store.asp?alternate=AN3-56
 
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GAHco said:
Using these the rudder pedals are not likely to stick at the pivot point.
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This is true ONLY if you drilled the holes on both ears of the rudder pedals at the same time with a long drill bit. If you did not, it is highly unlikely that holes on each side perfectly align with each other. In this case, especially since some of those holes are drilled through 1/8" stock, using a single long bolt will actually create more binding in the system than would using two individual smaller bolts. As best I can tell, the springs are the only solution for these cases where the holes on each side of the pedal were not drilled entirely inline.
 
Thanks for the tip!

alpinelakespilot2000 said:
This is true ONLY if you drilled the holes on both ears of the rudder pedals at the same time with a long drill bit. If you did not, it is highly unlikely that holes on each side perfectly align with each other. In this case, especially since some of those holes are drilled through 1/8" stock, using a single long bolt will actually create more binding in the system than would using two individual smaller bolts. As best I can tell, the springs are the only solution for these cases where the holes on each side of the pedal were not drilled entirely inline.
Click to expand...

Thanks for the tip, excellent suggestion!

I have a 12 inch #10 bit that should easily handle the job when I get to that task.

(I am just starting on the Fuselage next)
 
I installed the -60 bolts (with extra washers) quite a while ago. The brakes sometimes still didn't spring all the way back--maybe 1/4" short. It was only a problem when I went to push the plane uphill back into the hangar until my first flight in the cold. Something about the cold air made it much worse and was affecting taxiing.

My solution: I removed the long bolts, drilled the holes out to #10 (I probably used #12 originally) and didn't tighten down the castle nuts at all. I spun them on just until they touched.

Problem solved. Brakes no longer drag at all.
 
AN3-56 Bolts

I just returned from Sacramento Sky Ranch, and got 5 AN3-56 bolts for $3.20 each. Mind you these were not the shiny gold colored bolts, but had more of a military surplus look, kind of a dull grey look, but were obviously unused. Coupling these with oil light hat bushings from McMaster Carr P/N 6338K311 $0.59 each, should make my brakes work smoothly for years to come (especially, since it’s still a few years to first flight) I’ll look into springs if there’s any hint of binding or not fully returning.

Something else to consider is the fact that opposite sides of the brake peddles are not parallel, as they taper towards the top, when I drill for the hat bushings I’ll spot face the angle / lever to make them run true.

FYI- when I bought my bolts from Sky Ranch only had 10 left.
 
springs for sticking brakes

I am resurrecting this thread as I am having sticking brake issues and would appreciate some help from those who may have been down this road already. I have read through this thread and most everyone has posted about the long bolts. Some have posted about adding springs to their brake pedals and that this has fixed their sticking brake problem.

I have been flying for a little over a year now with my 9A. I have recently noticed my brakes are sticking when I attempt to pull it into the hangar with my tow bar. Just this past weekend I was really struggling to tug it into the hangar. I climbed into the cockpit, reached down to the pedals and pulled the tops back toward the seat. The plane rolled effortlessly after that.

From this experience it looks like I need to do something to remedy my sticking brakes. I have not read in this thread about information on where anyone is getting the springs needed or how they are mounted. I would like to install the springs to see if that will fix my sticking brakes. What springs are people using? How are they mounted? If anyone has pictures of their spring installation I would appreciate seeing them.

Thanks
 
If you really want to go first class, get the Grove cylinders. They have springs built in, and most importantly, the shaft length is adjustable, which makes it a piece of cake to get just the right angle on the brake pedals.

http://groveaircraft.com/mastercylinders.html

IMHO worth the upgrade. Just call Grove and tell them which aircraft you have.

Not affiliated, just a happy customer.
 
I agree that a lot of the brake problems you hear about are people torquing down the nuts to 25+ inch/pounds. Remember that this is a rule of thumb, not gospel. I've seen a lot of in-process RVs with brakes tightened down like that. Use your head -- how do you think it's possibly supposed to spin when tightened down to 25 lbs and there's no bearing in there?
 
PCHunt said:
If you really want to go first class, get the Grove cylinders. They have springs built in, and most importantly, the shaft length is adjustable, which makes it a piece of cake to get just the right angle on the brake pedals.

http://groveaircraft.com/mastercylinders.html

IMHO worth the upgrade. Just call Grove and tell them which aircraft you have.

Not affiliated, just a happy customer.
Click to expand...
Thanks for the information on the Grove master cylinders. Definitely seem to be a good setup. However, since I already have the standard cylinders from Van's I think getting a spring to return the brake pedal back after releasing them upon application would be a whole lot easier on my wallet.

I am still looking for any pictures and/or information on installing such a spring on my existing setup.
 
Here is a picture of mine under construction.
1096404045_mC2ob-M.jpg

I found all of the necessary components at the local industrial hardware supplier (Marshall's Hardware in San Diego). Your local ACE or True Value store would probably have all of this stuff. You need compression springs, sliding collar with set screw and nylon washers on the bottom of the springs.
 
bruceh said:
. . .I found all of the necessary components at the local industrial hardware supplier (Marshall's Hardware in San Diego). Your local ACE or True Value store would probably have all of this stuff. You need compression springs, sliding collar with set screw and nylon washers on the bottom of the springs.
Click to expand...
Super thanks Bruce. Exactly what I needed to know.
 
bruceh said:
Here is a picture of mine under construction.
1096404045_mC2ob-M.jpg

I found all of the necessary components at the local industrial hardware supplier (Marshall's Hardware in San Diego). Your local ACE or True Value store would probably have all of this stuff. You need compression springs, sliding collar with set screw and nylon washers on the bottom of the springs.
Click to expand...

Keep in mind when you go to rebuild a master cyl, that you remove the bur that the set screw caused on the shaft or you will destroy the new seal.
 
I would suggest using something to prevent the spring from rubbing/chafing the piston shaft. That could cause a leak when applying the brakes.

Most Ace hardware stores carry something close to these nylon flanged bushings. The ones I got work well, they center the spring, and protect the piston shaft.

The image below is from Mc Master Carr, but anything close should do fine.

flangedsleevecollage.gif
 
ACE Hardware

Well guys, I just returned from ACE Hardware. Here is what I ended up purchasing:
2 3" long 1/2" dia. compression springs - $1.89/ea
4 plastic bushings/washers - $.43/ea
Total price plus tax - $5.53

Getting information from VansAirForce guys like all of you - PRICELESS!! :D
 
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