Anticept Posted April 27, 2016 Report Share Posted April 27, 2016 Good thing Morden, because you can't baby matco liners. That makes them wear faster. If you talk to matco tech support, they will tell you about the tests they did. Brakes lasted much longer with moderate braking vs light braking. They found that taxiing was particularly bad when people rode the brakes. Also, rotor wear is important. The pistons in these brakes do not have a lot of travel. Worn liners and worn rotors means it's very easy to lock the brakes up. Matco has a specification of how thick the rotor needs to be (page 12). Adhere to it! We had one get to .140 before I noticed, and I noticed because the brake locked up and the pilot didn't check the pads either! Link to comment Share on other sites More sharing options...
FlyingMonkey Posted April 27, 2016 Report Share Posted April 27, 2016 Good thing Morden, because you can't baby matco liners. That makes them wear faster. If you talk to matco tech support, they will tell you about the tests they did. Brakes lasted much longer with moderate braking vs light braking. They found that taxiing was particularly bad when people rode the brakes. Also, rotor wear is important. The pistons in these brakes do not have a lot of travel. Worn liners and worn rotors means it's very easy to lock the brakes up. Matco has a specification of how thick the rotor needs to be (page 12). Adhere to it! We had one get to .140 before I noticed, and I noticed because the brake locked up and the pilot didn't check the pads either! Oh yeah...another thing about worn pads with the Matcos: If they are worn enough, the cylinder travel is too great and the cylinder will cock itself at an angle in its recess, and LOCK the brake onto the rotor. You can get it back in to release the brake, but it will probably require some vice grips and a lot of cussing. If it happens on roll out you will probably end up in the weeds and break your nice airplane. Guess how I know this... (no, I didn't have it happen on the runway, so no broken airplane) Link to comment Share on other sites More sharing options...
Roger Lee Posted April 27, 2016 Report Share Posted April 27, 2016 Oh yeah...another thing about worn pads with the Matcos: If they are worn enough, the cylinder travel is too great and the cylinder will cock itself at an angle in its recess, and LOCK the brake onto the rotor. You can get it back in to release the brake, but it will probably require some vice grips and a lot of cussing. If it happens on roll out you will probably end up in the weeds and break your nice airplane. Guess how I know this... (no, I didn't have it happen on the runway, so no broken airplane) Andy Is absolutely right. If you allow our brake pads to wear too far the pistons come out so far they cock to the side and lock the brakes. Just had one like that 3 weeks ago. mark my words it always seems to happen on the runway and you can't push it off. Link to comment Share on other sites More sharing options...
Roger Lee Posted April 27, 2016 Report Share Posted April 27, 2016 Eddie, I miced a new set of Marc pads. They are 3.7mm which is about how thin Matco's are when you need to replace them. Matco's can get to about 3.25mm or there about. The Marc pads are a harder material, but I think that makes them a worse braking brake too. The marc's fade with heat and have less stopping power. Plus the Marc master cylinder puts out about half the pressure that a Matco does. Link to comment Share on other sites More sharing options...
Doug G. Posted April 27, 2016 Report Share Posted April 27, 2016 Andy Is absolutely right. If you allow our brake pads to wear too far the pistons come out so far they cock to the side and lock the brakes. Just had one like that 3 weeks ago. mark my words it always seems to happen on the runway and you can't push it off. I got lucky, it happened when I did my run-up on the taxi way before requesting clearance to take off. I had to be towed back to my hangar. Link to comment Share on other sites More sharing options...
Runtoeat Posted April 28, 2016 Report Share Posted April 28, 2016 I didn't have the notch on my last set of pads to tell me how worn they were. Roger, if your saying the Matco's should be replaced when they get to be 3.25 mm (about .125") I'm very lucky my Matco brakes didn't lock up on me - they were about .080". Another tell-tale your pads are worn is to watch the level of the brake fluid in our little fluid reservoir. Link to comment Share on other sites More sharing options...
Roger Lee Posted April 28, 2016 Report Share Posted April 28, 2016 Since matco's are riveted to the shoes the greater worry is getting down to the rivets and ruining your disc. I have seen 3 sets of very worn thin pads lead to brake lockup with both Matco and Marc. Link to comment Share on other sites More sharing options...
Runtoeat Posted April 28, 2016 Report Share Posted April 28, 2016 From the information posted here, looks like replacing pads when they get down to 1/8" thickness or are at the bottom of the "notch" (if the pads have this) is a good rule of thumb Link to comment Share on other sites More sharing options...
FlyingMonkey Posted April 28, 2016 Report Share Posted April 28, 2016 Concur. Just to straighten the record, it's now referred to as, "the Morden notch." Early on, in my previous life, I was told by many senior pilots, it was never good to have a procedure named after you. I believe "the Moden notch," is an exception to that rule. Ha! Well, I only found this procedure by letting my pads wear to the point of brake lock, so I think the rule of thumb stands. I'll wear it as a badge of shame / honor! Link to comment Share on other sites More sharing options...
Runtoeat Posted April 28, 2016 Report Share Posted April 28, 2016 Andy, I think Bill has tagged you with something that those who hang out on this forum will feel compelled to refer to when the subject of brakes comes up! Link to comment Share on other sites More sharing options...
FastEddieB Posted April 29, 2016 Author Report Share Posted April 29, 2016 Eddie, what is the difference in the thickness where you show measuring it and the area around where the pins are? Measured today, and came up with .157" at the pins, where zero wear should be expected. This is from the AMM: I figure that has to be a mistake, or if I were cynical, maybe a way to sell more brake rotors! Maybe a conversion error or other brakes had been spec'd at one time and it never got changed. Regardless, I'm no longer worried about it. But I will measure at each annual and keep track . Link to comment Share on other sites More sharing options...
Anticept Posted April 29, 2016 Report Share Posted April 29, 2016 I just check marc ingegno's website. The discs ship 4mm thick from the factory. That's .157 inches. So basically, that AMM is impossible to comply with! You should send them an email and let them know. Link to comment Share on other sites More sharing options...
Roger Lee Posted April 30, 2016 Report Share Posted April 30, 2016 Marc Ingegno in Italy will never respond. Even MFG's have a hard time conversing with them. That's one reason FD dumped them, plus they are expensive coming over here and backward in trying to make the disc float which causes poor performance and they are that great in quality. Even the wheels flex and change size with air pressure in the tires which also cause the disc to bind. They do make good targets. Link to comment Share on other sites More sharing options...
FastEddieB Posted April 30, 2016 Author Report Share Posted April 30, 2016 ...and backward in trying to make the disc float which causes poor performance... To be fair, high performance motorcycles routinely use floating rotors, so at least the concept is sound. Link to comment Share on other sites More sharing options...
Anticept Posted April 30, 2016 Report Share Posted April 30, 2016 I meant let the manufacturer of your skyarrow know... Link to comment Share on other sites More sharing options...
FastEddieB Posted April 30, 2016 Author Report Share Posted April 30, 2016 I meant let the manufacturer of your skyarrow know... I got that - I will. Link to comment Share on other sites More sharing options...
Anticept Posted April 30, 2016 Report Share Posted April 30, 2016 Marc ingegno responded. Wear limit is 3.2 mm. Link to comment Share on other sites More sharing options...
Roger Lee Posted April 30, 2016 Report Share Posted April 30, 2016 3.2mm = 1/8". So your still good on the disc. 1mm = 1/64" for the pads. Link to comment Share on other sites More sharing options...
FastEddieB Posted April 30, 2016 Author Report Share Posted April 30, 2016 Decimally, 3.2mm = .126", so the manual is clearly wrong and I've got lots and lots of life left on both sets of rotors. I put that limit on my checklist and I'll inform Magnaghi Monday. Link to comment Share on other sites More sharing options...
Roger Lee Posted April 30, 2016 Report Share Posted April 30, 2016 " so the manual is clearly wrong" and it's not even Rotax. Link to comment Share on other sites More sharing options...
Runtoeat Posted April 30, 2016 Report Share Posted April 30, 2016 While we're talking brakes, Roger, do you have a part no. for the Matco bearings used in the main wheel? I might have a unique bearing since I ordered and installed the Matco wheel and brake assy with 1.25" axle instead of the more common .75" axle. Also, I'm wondering if just the rubber bearing seal can be ordered or must a new bearing be purchased if the seal is worn? Update: Found the bearing. Timken LM67000LA 902A1. It would be nice if the seals could be replaced instead of buying the whole bearing. Link to comment Share on other sites More sharing options...
Roger Lee Posted April 30, 2016 Report Share Posted April 30, 2016 If the seal is gone then a new bearing is needed. Did you damage the seal? Usually a bearing goes before a seal. http://www.matcomfg.com/ROLLERBEARING125-idv-3108-44.html Link to comment Share on other sites More sharing options...
Runtoeat Posted May 1, 2016 Report Share Posted May 1, 2016 Don't need a seal. Just giving brakes and bearings some TLC. While repacking the bearings I thought about the seal getting a pretty good work out. Was wondering how long it goes before it stops sealing effectively. Link to comment Share on other sites More sharing options...
Roger Lee Posted May 1, 2016 Report Share Posted May 1, 2016 Haven't seen one fail yet. Link to comment Share on other sites More sharing options...
Tom Baker Posted May 1, 2016 Report Share Posted May 1, 2016 If I was guessing the wear will be on the wheel instead of the seal. I've seen to many cases on airplanes where a soft part like a rubber baffle seal or hose rubbing on aluminum will wear the aluminum and leave little or no mark on the softer part. Link to comment Share on other sites More sharing options...
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