Matco brakes

[tinturtle]

On my Kitfox 3 I have eight inch rims with Matco brakes. Even though I have bled them a number of times the right brake has not the power of the left one. Is there a way to adjust the pads? I sure this is simple to some but I am baffled.

[KFfan]

Based on automotive experience with disc brakes, there is no adjustment. The system is quite simple. If bleeding is not the resolution, I would look at fluid flow. Are the seals in the cylinder good? Is the brake line rubber or metal? If rubber, has it ever been kinked? The rubber lines can fail internally. Do the components at the wheel move freely?

[Micro Mong Bldr]

Contamination on the right side brake pads? Are both disks equally smooth surface finish?

[tinturtle]

Thanks for the suggestions. After the holiday weekend I will try Matco directly. Meanwhile, I will jack that wheel to see if there is any slipping or dragging. The plane had been on floats for years. When I got it I reinstalled the landing gear/brakes. I flushed it all using the 5606 aircraft brake oil and installed all new lines. There appears to be no leaks but rechecking cannot hurt. Thanks again. Also I plan to adjust the length of the master cylinder rod on the pedal.

[cgruby]

Welcome to the club. I have a type III with absolutely lackluster brakes. Here are some of the things I've done. I changed the brake pedal geometry, installed new wheel cylinders, bled gallons of fluid through both sides. It is impossible to lock a wheel and pivot the airplane around on one wheel. The pedals are definitely not firm.

I've written to MATCO and was referred to their web site where they have a wealth of information there. It's just a matter of diving in and going through the hassle again.

One of the most significant pieces of information they offered, was that you must have a pressure of 450psi at the wheel cylinders to achieve maximum breaking. Interesting enough, any more than that can actually reduce brake effectiveness due to deformation of the wheel cylinders. I have a pressure gage ordered and will start on it once again once it's received.

Spend a little time poking around in their web site and you'll find a wealth of information there.

Happy Hunting,

[tinturtle]

I got the whole right wheel assembly apart today. I have to say the plane had been on floats since '93 and the wheel/strut assemblies had been stored in a warehouse. I had put fresh oil through them before attaching but never disassembled the brake units. I found some gunk in and around them. it looks like oil that had been on them for years and mixed the dust dropping on them from years of storage. I want to spray the pad surfaces with brake cleaning fluid. Is that acceptable?

[tinturtle]

I found trouble shooting tips on Matco's site. I used their suggestion to sand the pad surfaces with 220 grit. I used a rifle bore brass brush to clean the insides of the tubes that allow the pads to move freely and polished the outside of same. Upon re-assembly I found no additional braking power. Maybe just the fact that I have 22" dia tundra tires gives the plane too big of a lever for these brakes designed so long ago. I'm going with the Fred Flintstone method of dragging my feet!

[Av8r3400]

I could never get my Matco brakes to work acceptably either.

When I converted to Grove gear, I used their double puck calipers on "normal" 6" wheels (with 22" Desser tires) with no change to the peddles or Matco masters. These brakes are now strong enough to hold the plane at a full power run-up, or even nose it over if I wanted.

I believe that the internal caliper design is just a poor performing setup.

[tinturtle]

Thanks for that last reply. You are not the first to tell me the Matco brakes are inadequate. Doug

[RobS]

Av8r3400 - what Grove brakes (model#) did you use? Were they a straight replacement for the Matcos, or did you have to make other changes to your setup?

[HighWing]

I could never get my Matco brakes to work acceptably either.

These brakes are now strong enough to hold the plane at a full power run-up, or even nose it over if I wanted.


In the old days - Sorry - the inability to nose over was considered a virtue. That being said, I have had Matco original kit supplied brakes on both my Model IVs. I was able to initiate a nose over on the first one, but caught it in time, and have had no issues with the new ones braking wise, except for having to replace the original 1992 pads - they crumbled and fell out. There are literally tons of guys out there still running their original Matco's but we each have our priorities for sure.

[tinturtle]

Because I could not get braking to my satisfaction I just got my taildragger endorsement in a Citabria Super Decathlon. With that plane you Can do the run ups properly and spin the plane 180 on one wheel. After seeing what very good brakes can do it makes me fearful with brakes on the Kitfox that takes a thirty foot circle to the left to 180 turn and virtually impossible to turn 180 to right. I hate to spend the money but the Grove system of two pucks sounds like the right ticket.

[DesertFox4]

I had Matco's on my model 4 tri-gear when it was first flown. Even after burning the rotors and pads in properly the Matco's were marginal at best.

I replaced them soon after with Cleveland brakes and wheels and the difference was incredible. I can do full throttle run ups with the 100 hp Rotax and I can lock up the main gear anytime with too much pressure on the pedals on blacktop runways. Makes for very short landings if needed.:eek:
They would certainly put a taildragger on it's back quickly if too enthusiastic on the brakes. The Grove wheels and brakes are as good as the Cleveland or better in stopping power.

I kept the Matco cylinders as they seem very effective if hooked to good calipers and pads.

[Av8r3400]

Av8r3400 - what Grove brakes (model#) did you use? Were they a straight replacement for the Matcos, or did you have to make other changes to your setup?

The Grove calipers were not replacements for the Matcos. I replaced the entire bungee gear system with Grove aluminum spring gear and their own brakes, wheels, axles and mounts.

I already had the parts off a parts plane, so I am not sure exactly what the part numbers are, but I believe this is the ones. Link (http://www.groveaircraft.com/61-1.html)

[RobS]

Thanks Larry!

[cgruby]

You know I've posted here several times pleading for answers to lackluster MATCO brakes on my Type III. Not having a lot of KitFox experience, I didn't know what to expect in regard to their brakes. I was lead to believe, I was the only one who had a problem, but now I see from these replies, the problem is systemic. It looks like everybody has the same opinion of MATCO brakes ............ sick!

I know what good brakes are and how to handle a tail-dragger without nosing it over, but I don't know how to function with brakes that "almost" work. A lot of people will tell you they never use brakes, well I'm here to tell you, that I do, and consider them mandatory or you're just a passenger during final roll-out. I'd sure like to hear from some of you who have a MATCO system with solid brakes.

Sorry for hi-jacking the thread.

I haven't given up yet, but I'm close.

Cheers,

[Av8r_Sed]

I've got the original Matco's with MC-1 cylinders (pilot side brakes only). They work fine with my 21" Nancos. I have almost nosed over twice now, but I think I've learned. I've done nothing special except for drilling the disks with lightening holes.

[HighWing]

I already posted my experience with the Matcos, but Paul's response reminded me of a couple of things. I replaced the original linings on both of the brake sets on the two Model IVs. The first one, I did drill the rotors for weight reduction, but on the second I reduced the rotor dimensions to only the portion that was actually in contact with the pads - also for weight reduction. The second time, I replaced the pads with Cleveland linings - Part # 66-106 (Aircraft Spruce) A caution, the rivets sold for the installation are too short by about a sixteenth inch or so.

[cgruby]

I've got the original Matco's with MC-1 cylinders (pilot side brakes only). They work fine with my 21" Nancos. I have almost nosed over twice now, but I think I've learned. I've done nothing special except for drilling the disks with lightening holes.

Thanks for the vote of confidence. My problem is still one of not getting all the air out when bleeding, because I still don't have a firm pedal. When (and if) I ever get that solved, maybe the brakes will be adequate.

Thanks again,

[cgruby]

I already posted my experience with the Matcos, but Paul's response reminded me of a couple of things. I replaced the original linings on both of the brake sets on the two Model IVs. The first one, I did drill the rotors for weight reduction, but on the second I reduced the rotor dimensions to only the portion that was actually in contact with the pads - also for weight reduction. The second time, I replaced the pads with Cleveland linings - Part # 66-106 (Aircraft Spruce) A caution, the rivets sold for the installation are too short by about a sixteenth inch or so.

Same response as before ...........

I'll keep working on the bleeding problem.
Thanks for the help,

[WWhunter]

I had a similar problem on my RANS with the MATCO brakes. It took a lot of bleeding to get the air out. I ended up using an oil squit can filled with brake fliud. I put a bunch of rags around the master cylinder resevoir to catch the overflow, when I was bleeding them. I attached a small, snug fitting tube from the squirt can nozzle to the bleed screw on the wheel cylinder and kept pumping in fluid until there was no longer any air visibly coming out of the master cylinder. I actually had to do it a couple of times, with testing the pedal hardness, before I finally attained proper working brakes. I have now moved up to 29" AkbushWheel Airstreaks on the plane and the single pucks are not suffiecient. I am going to have to move up to dual calipers or double puck brakes. :(

[tinturtle]

Am I asking too much to be able to step on one brake, spin around 90 degrees and not have that wheel move at all? Maybe I am asking too much. I see all the comments about nosing over. I'd love to have that concern

[tinturtle]

Anyway, I love being able to converse with guys having to deal with similar problems. I had to put the Kitfox in the barn. I fly to Alaska tomorrow to run an old power scow buying salmon in Bristol Bay. I have to work these next two months so I can afford this little 80HP mistress. No internet on the boat. Just dreamin' about flying!Thanks for listening.

[PapuaPilot]

Reading about some that have Matco brakes that work fine and some that don't I think it would be good to ask if those who are having problems have done a proper break in procedure on the brake pads? Does Matco have a break in procedure for new pads? If you don't do a proper break in you can end up with glazed pads that are virtually ineffective. Just wondering. ;)

[DesertFox4]

Phil, I broke mine in according to Matco's directions. Didn't glaze the pads or rotors. Still somewhat lackluster stopping power. No soft pedals or trapped air in the stainless lines. Go figure.

[Dusty]

Has anyone experimented with different pad materials?
Would softer pads give better braking?
I would sacrifice pad life for a little bit better brakes,still running original 1991 pads!
My matco's are ok for a 2 stroke kf3 but would struggle with a4stroke

[cgruby]

Today I measured the hydraulic pressure down at the wheel cylinders. With max effort I can get 400 to 500 lbs. I had a long conversation with the MATCO service tech and he says that the pressure is just what I should have, but says that it's unusual for a KitFox to have that much pressure. It has to do with the geometry of the brake pedal and the brake master cylinder.

What we decided was to install a second wheel cylinder. I had already purchased new ones, so I'll just add my olds back on. They are sending me a new brake mounting plate to incorporate the two cylinders.

I guess the next thing you'll hear from me is how I managed to stand this thing on it's nose.

It should be interesting to see how this plays out.

Cheers,

[cap01]

thanks for the updates . would be helpful when you get this two cylinder setup completed to have some pictures . I'm sure there a lots of followers of this.
good luck .

[cgruby]

thanks for the updates . would be helpful when you get this two cylinder setup completed to have some pictures . I'm sure there a lots of followers of this.
good luck .

Will do. On MATCO's web site they have a drawing of this configuration. I'm sure anxious get it installed and try it out.

[cgruby]

Well, I promised to post an update when I got the dual wheel cylinders installed, so here it is, such as it is .............I contracted some sort of respiratory infection which prevented me from making better progress.

The cylinders were installed onto the backing plates. Centering them on the axels was made more difficult in that the hole was much larger hole than required. It's a pretty snug fit, but I managed to get it installed using only 3 bolts as opposed to 4. According to MATCO, three is sufficient.

Some of my brake disc hold down screw receptacles were stripped and were repaired using Heli-Coils. Once the wheel is on, It's virtually impossible to inspect the operation for freedom of movement, so it was bleeding time and take it out and try it.

Bleeding went relatively smooth, except for spilling fluid all over the place. It's important to fabricate some fittings so the bleeding apparatus can be coupled up to avoid a lot of spillage, thus contaminating the pads.

The next step was to take it out and taxi test it. Initially, I could not tell any difference in the braking authority at all. After a few runs up and down the runway, conditioning the brake pads, I actually was able to lock up one wheel and pivot on that wheel, but not without a lot of effort. I never was able to lock up the right side. I'd say I might have improved the overall capability about 25%.

The plan now is to bring the airplane back home where I can go over the whole operation carefully to make sure something isn't binding somewhere. I want to also measure the pressure again to make sure I have 450psi at the wheels.

I had expected a dramatic change, and to say I'm a little frustrated is putting it mildly, but I think I'm making a little progress nevertheless.

[Dusty]

Is that the recommended way to plumb your brakes?
getting the air out must have been a nightmare!
Did you de'mount your calipers or bottom bleed then reverse flow to get the last bit of air out?
I am very interested to see how this works out as is something I have
considered

[HighWing]

Is that the recommended way to plumb your brakes?
getting the air out must have been a nightmare!
Did you de'mount your calipers or bottom bleed then reverse flow to get the last bit of air out?

I would suggest using a "T"and then run separate lines to the uppermost fitting on the calipers. Then bleeding from the bottom fitting one at a time should enable all the air to be removed from the lines.

[cgruby]

Is that the recommended way to plumb your brakes?
getting the air out must have been a nightmare!
Did you de'mount your calipers or bottom bleed then reverse flow to get the last bit of air out?
I am very interested to see how this works out as is something I have
considered

The brakes are plumbed as per MATCO, in series. I probably would have paralleled them myself. Bleeding with a pressure pot seems to work very well as you can move a lot of fluid in a short time, hopefully causing migration of most of the air.

[cgruby]

I would suggest using a "T"and then run separate lines to the uppermost fitting on the calipers. Then bleeding from the bottom fitting one at a time should enable all the air to be removed from the lines.

If MATCO had not specifically stated they were to be in series, I would have done as you said.

[HighWing]

Ok, if the recommended routing is series. I would then select the lowest point in the system as the inlet for the bleed line, then route the brake lines from the top of that caliper to the bottom of the second caliper. The line to the master cylinder would then run from the top of the second caliper. Unless you are running gph volumes of fluid through the system, I can't imagine getting all the air out with the bleed insert at the top. Or maybe I am misreading the picture. When bleeding my system, even a small visible bubble of air in one of the Nylaflow lines will result in a spongy feeling. And yes, I have no problem locking a brake and pivoting a 360 on that wheel - either side. A thought, if this has been a constant problm, could it be a mis-adjustment of the tailwheel that it won't unlock and freely pivot.

[cgruby]

Thanks Lowell, it's gratifying to know at least some KF's can lock a wheel up and pivot on that wheel.

When I bleed I use a pressure pot and force fluid up to a catch jar connected to the reservoir fill port. It seems to work very well. The pedals seem to be very firm.

I went over the installation yesterday with a fine tooth comb. The questionable items I find are:

1. Only about one half of the brake linings are in contact with the disc.
2. The calipers seem to deflect or deform under pressure.
3. The optimum brake pedal to master cylinder lever ratio is 2.5 to 1. My brake pedal is 2.5 inches long whereas the master cylinder lever is 1.875 inches making for a ratio of 1.3 to 1. I'll plan to shorten the master cyl lever to 1".

I guess the next step is to devise an anchor which can be thrown out when one sees a need to stop.

[cgruby]

Well gents, I'm here to tell you that the brake issue, or the lack of has finally come to a successful conclusion. I can actually stop and pivot on one wheel.

The approach was to install two MATCO brake wheel cylinders for each wheel. Care must be taken that the brake mechanism does not come in contact with the back plate mounting bolts. Metal will have to be removed from the back plate to make this happen.

Secondly, I measured 450psi at the left wheel and 375 at the right. I could lock the left but not the right. I decided to put in new master cylinders, which are the type that uses an external reservoir. Additionally I added a dual parking brake valve.

Today's test was great I can run her up to max throttle with no creep, stop on a dime and give you a nickel change. She pivots well and the brakes are nice and smooth with no over-sensitiveness.

I plan to now go out and enjoy my airplane.

Cheers,

[WWhunter]

It looks like you are using one of the real old style calipers and the newer style in your dual setup. I am glad it is working out for you since this is exactly what I was going to attempt. The newer MATCO single calipers work fine up to the 26" AkBushWheel Airstreak tires but when I installed the 29" Bushwheels my braking mirrors what you were experiencing.

Since the plane originally had those old style (silver-gray) round type, I was going to sell them and buy another set of the new style. Now that I read that you are getting great braking with one of each I will keep them and just get another backing plate! AWESOME!! You just saved me many hundred dollars. :)

[JorgeEC-YUQ]

Hi everyone,

Thanks for the pics ChuckG, I also decided to install the double puck from Matco on my 8" douglas wheels.

Indeed I found this thread so helpful I wanted to share some more pictures and the problems I found while installing it so it helps anyone who decides to go this way... specially for the non mechanical oriented people like me!

I had troubles to perfectly center the supporting pad with the axle so I made a cylinder to place it in to the right position. I would strongly recommend to make something like that so is not moving while drilling.

The mounting pad will only accept one position so the gear legs doesn't obstruct the brake pads. Make sure you drill it in the right position (yeap ... I miss that the first time, that is you can see some extra holes:mad: ).

I removed some material from the gear leg mounting pad and I was able to drill the 3 bolts it in such a way it wouldn't interfere with the movement of the brake pads.

My problem was other: even by getting the thing as centered as I could, the inner braking pads were touching the brake disc supports. I had to take some material away from both, the braking pads and the disc supports... did anyone had the same problem?

My understanding is that this aluminium supports where welded in the rim by the constructor and they were slightly too big (indeed one of them was broken).

As well, does anyone know where to get some brake discs? are these from Matco?

Hope it helps!
Cheers,
Jorge

[HighWing]

1. Only about one half of the brake linings are in contact with the disc.
2. The calipers seem to deflect or deform under pressure.
3. The optimum brake pedal to master cylinder lever ratio is 2.5 to 1.

Re reading this thread I finally noticed the highlighted sections in the above quote.

In the old days, the bungee gear was notoriously toed in from the factory. In my opinion it is the primary reason for the squirrely reputation of the early Kitfox. Then the factory came out with a note in one of their early Kitfox Times magazines with a technique for aligning the wheels to parallel tracking. I did the deed and found that by putting the padded pipe on the axles and applying a little muscle, I could get straight tracking, but then noticed that all the realignment came at the expense of a bent axle. I found that the brake calipers were no longer perpendicular to the axles, but remained true to the toed in gear legs. I shimmed the calipers with washers strategically placed between the caliper and mounting pad to approximate a 90 degree relationship to the axle. This was done before first flight so I never experienced brake issues with that airplane. Maybe this is the genesis of some of the braking issues with the bungee geared Kitfoxes - poor lining contact with the rotor.