Browncbr1 Posted May 31, 2015 Report Posted May 31, 2015 ive read that some people have said that mooney brakes are not the most robust or lack some authority compared to other planes. Im not sure if those accounts are the standard or the exceptions. I installed new brake pads and bled lines thinking it would help. They don't feel spongee. But, they don't stop my plane very well at all. I was trying to make a turn off today and I was stomping as hard as I could and it was just slowing down at a comfortable rate, not representative of how hard I was pushing. . Other planes I've flown would have locked up the wheels had I been pushing that hard. Does this sound like a problem or just how the mooney brakes are? There is literally no way I would be able to lock up the wheels with these brakes. This is all with just me... Wondering how it would be at gross Quote
stevesm20b Posted May 31, 2015 Report Posted May 31, 2015 Sounds like you have a problem. I don't have a problem slowing down or stopping my Mooney. Quote
gsxrpilot Posted May 31, 2015 Report Posted May 31, 2015 Yeah, somethings not right with those brakes. Mine will stop the plane short or lock up the wheels if I don't dump the flaps. Quote
bonal Posted May 31, 2015 Report Posted May 31, 2015 +1 on the possibility there is an issue with your brakes, mine will lock if I apply sufficient pressure. Quote
cliffy Posted May 31, 2015 Report Posted May 31, 2015 How long has it been since the wheel cylinders were apart and cleaned, new orings and bled? How old are your brake discs? Do the wheel cylinders slide easily on the slider pins in the mount? Â Hopefully the answer to these questions will fix your problem You should be able to lock them up. Quote
Hank Posted May 31, 2015 Report Posted May 31, 2015 How long has it been since the wheel cylinders were apart and cleaned, new orings and bled? How old are your brake discs? Do the wheel cylinders slide easily on the slider pins in the mount? Â Hopefully the answer to these questions will fix your problem You should be able to lock them up. The brake fluid will turn to gel over time, too. Check yours, you may want to flush it all out and put in new, then bleed them all over again. I routinely make the 2500' turn off with little braking. Quote
kerry Posted May 31, 2015 Report Posted May 31, 2015 Cleveland brakes are probably most desirable brakes for aircraft and that's what's on your Mooney. Quote
Browncbr1 Posted May 31, 2015 Author Report Posted May 31, 2015 It just came out of annual and my mechanic said he replaced the left slave cylinder seal due to some moisture showing. He also installed brake pads on both sides and bled the system at my request. It seems the same as before. I can't imagine him doing all that and not greasing the slider pins. It brakes evenly. That is to say that one side isn't stronger than the other. Are the right and left systems completely independent of each other? It's odd that they would brake very evenly poorly. Quote
Browncbr1 Posted May 31, 2015 Author Report Posted May 31, 2015 Not sure how old rotors are, but they seem to look ok... I'll check again. Quote
carusoam Posted May 31, 2015 Report Posted May 31, 2015 Breaking is at best 'not good' compared to modern autos.... This is a function of their tiny size and where the brakes are located. Only on the two back wheels. Realistically, when you brake too hard, they will lock-up. A set of brakes that is working properly will be controllable from light braking to full braking. If they lock up, let up, then reapply. If you apply full force to the brakes and only slow gently, you get an uneasy feeling and post a question on MS. Some thing is not right. But it is usually easy to make right. +1 on the replace old gunky red gel with fresh cherry juice... Go Mooney! Best regards, -a- Quote
MB65E Posted May 31, 2015 Report Posted May 31, 2015 I don't think the pads have broken in yet. Give it some time and they will improve. However, I'd have your tech looks at it again with a fresh set of eyes. Make sure the fluid is topped, and double check the pads and rotors. I just taxied a 36'' wheeled Huskey that had new pads on it. It was a miserable Taxi. -Matt 1 Quote
Alan Fox Posted May 31, 2015 Report Posted May 31, 2015 I would lean towards a new set of rotors , these are overlooked a lot , when they wear they do not wear evenly , and they get a glaze over years of use , that is not conducive to good friction.....If you have a good solid pedal(s) I don't think that it is a fluid or slide issue.....although fresh fluid is a great Idea from preventative maintenance standpppoint....p Quote
N601RX Posted May 31, 2015 Report Posted May 31, 2015 Rapco and Cleveland both have a break in procedure for their pads. Did this get performed? Quote
Browncbr1 Posted May 31, 2015 Author Report Posted May 31, 2015 I can understand how pads may need to be broken in if the rotor isn't perfectly smooth. Perhaps it will get better, but will check everything again first. But, this was somewhat how it was with the previous pads that were quite worn already. I didn't do any break in procedure and wasn't advised by anyone until now. And I just had one landing on these pads before the above described scenario. Quote
bonal Posted May 31, 2015 Report Posted May 31, 2015 New pads on mine and if all goes as planned annual should be done tomorrow and I will be doing my imitation of a fearless test pilot. Will note brake performance. Some brake pads require a run to fully hot to break in so we shall see how they perform but of corse there will be a number of things that will be tested on this flight. Quote
Guitarmaster Posted May 31, 2015 Report Posted May 31, 2015 There was a post here on MS a short time ago regarding bleeding. Â I'll see if I can find it. Â Basically, he had trapped air where the flexible line is connected to the hard line. Â He called it an "old motorcycle trick" to bleed at the fitting. Â Â I have had the same problem with, and still do to some extent, my brakes. Â Bleeding doesn't help and new pads (mine were worn to the rivets) helped a little, but not a whole lot. Â My next step is to try this "trick." Â Good luck! Quote
Guitarmaster Posted May 31, 2015 Report Posted May 31, 2015 Here it is... Â http://mooneyspace.com/topic/15390-bleeding-air-out-of-brakes/?hl=motorcycle Quote
Andy95W Posted May 31, 2015 Report Posted May 31, 2015 I can understand how pads may need to be broken in if the rotor isn't perfectly smooth. Perhaps it will get better, but will check everything again first. But, this was somewhat how it was with the previous pads that were quite worn already. I didn't do any break in procedure and wasn't advised by anyone until now. And I just had one landing on these pads before the above described scenario. The break-in procedure (brake-in?) is actually called "glazing", and while it's bad for car brakes, our organic brake pads actually need it. You basically taxi the airplane at about 1800 rpm or so for about a mile, then let them cool and go fly. If that doesn't work, check the thickness of your brake discs. If they are well within spec, bleed per the aforementioned Mooneyspace post. Good luck! When you get them right, you'll appreciate the effort you put into it. Quote
Browncbr1 Posted May 31, 2015 Author Report Posted May 31, 2015 I'll taxi some riding the brakes to see if the glazing helps. Quote
Yooper Rocketman Posted June 1, 2015 Report Posted June 1, 2015 I changed the pads on my Rocket during my recent annual and forgot about the break-in procedure. Â Thought I was going off the runway the first landing. Â I complained to my hangar partner (an A&P) and he asked if I did the break-in procedure?. Â I'm thinking there's more to this that just breaking them in. Â Well, that fixed the problem. Quote
Browncbr1 Posted June 1, 2015 Author Report Posted June 1, 2015 Glad to know that I'm not the only one. Will update after doing the break-in procedure. Quote
bonal Posted June 1, 2015 Report Posted June 1, 2015 Thanks for the correction in terminology yes "glazing" haven't heard the term in ages. I used to run Ferodo pads on my race bikes and had to glaze them to smoking hot twice (2 heat cycles) before they would function. I'm glad this subject came up because I no doubt would have forgot to glaze my new pads before my test flight. Quote
bonal Posted June 2, 2015 Report Posted June 2, 2015 Annual done test flight complete and yes new pads were real weak at first. After a handful of hard stops during taxi they improved some and with a full stop on runway after landing they felt ok but I think will need some more glazing. Quote
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